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Page 1: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Nosocomial PathogensNNIS Jan 1990 - Mar 1996

0

5000

10000

15000

20000

25000

30000

35000

40000

Urinary TractInfection

Surgical SiteInfection

BloodstreamInfection

Pneumonia Other Sites

Nu

mb

er o

f Iso

late

s

Burke JP N Engl J Med 2003348651-656

Presenter
Presentation Notes
SSI are the second most common cause of nosocomial infections Up to 2-5 of pts undergoing clean extraabdominal operations and up to 20 undergoing intraabdominal operations will develop SSI

Bacterial dose Virulence

Impairedhost resistance

EPIDEMIOLOGYwound classification I Clean

II Clean contaminated

III Contaminated

IV Dirty procedures

skin andmusculoskeletal soft tissues

Hollow viscus hasbeen opened

Bacteria introduced to Sterile body cavity

To Control established Infections

Presenter
Presentation Notes
Issues related to bacterial contamination have been well defined Clean surgical procedures are those where operations has affected only integumentary and musculoskeletal soft tissues13Clean contaminated procedures are those where a hollow viscus eg alimentary biliary genitourinary has been opened under controlled circumstances elective colon surgery13Contaminated procedures are those where bacteria has been introduced into a normally sterile site eg penetrating abdominal trauma13Dirty procedures are those where surgery is performed to control established infection eg colon resection for complicated diverticulitis 13Traumatic wounds with retained devitalized tissue foreign bodies or fecal contamination perforated viscus acute purulent bacterial inflammation

Sabiston Textbook of Surgery 18th ed

NNIS risk index 0 to 3 points (1) American Society of Anesthesiologists (ASA)

Physical Status Classification of gt2 (2) Contaminated or dirtyinfected wound classification (3) length of operation gtT hours where T depends

upon the operative procedure being performed

Index 1 (0 points) 15Index 2 (one point) 29Index 3 (two points) 68Index 4 (three points) 13

Elective Surgical ProceduresHair RemovalClipping hair just before case is best

Hair Removal Method Infection Rate

PM Razor 52 - 88AM Razor 64 - 10PM Clipper 4 - 75AM Clipper 18 - 32

Alexander JW et al Arch Surg1983 118347-352

Shaving Clipping and SSI

Cruse Arch Surg 1973 107 206

Infected

23

17

09

0

05

1

15

2

25

Shave Clip Neither

Fundamentals of Antibiotic Administration

Once the incision is madeantibiotic delivery to thewound is impairedMust give before incision

ABXABX

SSIs and Glucose Levels CTS pts

012345678

100ndash150 150ndash200 200ndash250 250ndash300Day 1 Blood Glucose (mgdL)

Dee

p In

fect

ion

Rat

e

Zerr KJ et al Glucose control lowers the risk of wound infection in diabetics after open heart operations page 360 Reprinted from The Annals of Thoracic Surgeons Vol 63

13 1625

67

P=0002

Glucose control (200 mgdl)decreases infection rate

Presenter
Presentation Notes
Elevated blood glucose levels after an operation are also associated with an increased risk of SSIs particularly in diabetic patients In an observational study Zerr and colleagues found a correlation between glucose levels immediately following surgery and the rate of deep sternal infection1 131313131313131313131313131313Reference131Zerr KJ Furnary AP Grunkemeier GL Bookins S Kanhere V Starr A Glucose control lowers the risk of wound infection in diabetics after open heart operations Ann Thorac Surg 199763356ndash36113

Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)

SENTRY ndash US and Canada 2000

Rennie RP et al Diagn Microbiol Infect Dis 200345287-293

N=1404 isolates

108 P aeruginosa

Enterococci 82

E coli 70

Enterobacter 58

Other 173 MSSA 309

MRSA ~15

Klebsiella 51

Presenter
Presentation Notes
In the SENTRY Antimicrobial Surveillance Program S aureus was found to be the predominant pathogen in nosocomial SSSIs MRSA was more prevalent than any other organism excluding methicillin-susceptible S aureus13S aureus accounted for 459 of isolates recovered from SSSIs among hospitalized patients at 24 sites in the United States and 5 sites in Canada between October and December 2000 Notably approximately 30 of S aureus isolates were methicillin (oxacillin)-resistant 13Other common pathogens isolated from SSSIs were P aeruginosa (108) Enterococcus spp (82) E coli (70) Enterobacter spp (58) and Klebsiella spp (51) The same rank order of pathogens in SSSIs was observed in both the United States and Canada

Microbiology Increasing proportion of

SSIs Antimicrobial-resistant

pathogensMRSAhelliphellip

Unusual pathogens Rhizopus oryzae Clostridium perfringens Rhodococcus bronchialis Nocardia farcinica Legionella pneumophila and

Legionella dumoffii Pseudomonas multivorans

From Weiss CA Statz CI Dahms RA et al Six years of surgical wound surveillance at a tertiary care center Arch Surg 1341041

Unusual pathogens of SSIs

bull Rhizopus oryzea ndashelastoplast adhesive bandage

bull Clostridium perfringens ndashelastic bandages

bull Rhodococcus bronchialis ndashcolonized health care personnel

bull Legionella dumoffii and pneumophila ndashtap water

bull Pseudomonas multivorans ndashdisinfectant solution

0

10

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30

40

50

60

1975 87 88 89 90 91 92 93 94 95 96 97 98 99

2000

2002

Res

ista

nt is

olat

es (

)

CDC MMWR 199746624-628 635 (1975 data) Lowy FD N Engl J Med 1998339520-532 (1987-1997 data) CDC NNIS System Report JanuaryndashNovember 1998 (1998 data) CDC NNIS System Report January 1990ndashMay 1999 issued June 1999 Am J Infect

Progression of Methicillin Resistant S aureus ndash United States13uarr

571553

Presenter
Presentation Notes
MRSA was first described in the United Kingdom in 1961 MRSA rates were low in US hospitals reported at lt 2 in the 1970s and early 1980s 13Examination of the rates of methicillin resistance in S aureus isolates in the United States by the CDC documents that rates have increased steadily over the past decade with a dramatic 40 increase during the last 5-year historical mean In 2000 553 of the S aureus isolates associated with a hospital-acquired infection in ICU patients were resistant to methicillin reflecting a further 31 increase in resistant S aureus isolates during the past year More recently in 2002 571 of S aureus isolates were MRSA accounting for an increase of 13 from the previous year1313

1

2

Surgical sitebull Hematoma

bull Foreign bodies

bull Dead tissue

bull Dead space

Presenter
Presentation Notes
Page 7 - Iron and impermeability of clot - silk suture - electrocautery and ischemia - these are importanat because we can control them - other include burn trauma bites PVD poor hygiene drains

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
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  • EPIDEMIOLOGYwound classification
  • Slide Number 17
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  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
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  • Shaving Clipping and SSI
  • Slide Number 41
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  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
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  • Surgical site
  • Slide Number 89
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  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
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  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
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  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 2: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Bacterial dose Virulence

Impairedhost resistance

EPIDEMIOLOGYwound classification I Clean

II Clean contaminated

III Contaminated

IV Dirty procedures

skin andmusculoskeletal soft tissues

Hollow viscus hasbeen opened

Bacteria introduced to Sterile body cavity

To Control established Infections

Presenter
Presentation Notes
Issues related to bacterial contamination have been well defined Clean surgical procedures are those where operations has affected only integumentary and musculoskeletal soft tissues13Clean contaminated procedures are those where a hollow viscus eg alimentary biliary genitourinary has been opened under controlled circumstances elective colon surgery13Contaminated procedures are those where bacteria has been introduced into a normally sterile site eg penetrating abdominal trauma13Dirty procedures are those where surgery is performed to control established infection eg colon resection for complicated diverticulitis 13Traumatic wounds with retained devitalized tissue foreign bodies or fecal contamination perforated viscus acute purulent bacterial inflammation

Sabiston Textbook of Surgery 18th ed

NNIS risk index 0 to 3 points (1) American Society of Anesthesiologists (ASA)

Physical Status Classification of gt2 (2) Contaminated or dirtyinfected wound classification (3) length of operation gtT hours where T depends

upon the operative procedure being performed

Index 1 (0 points) 15Index 2 (one point) 29Index 3 (two points) 68Index 4 (three points) 13

Elective Surgical ProceduresHair RemovalClipping hair just before case is best

Hair Removal Method Infection Rate

PM Razor 52 - 88AM Razor 64 - 10PM Clipper 4 - 75AM Clipper 18 - 32

Alexander JW et al Arch Surg1983 118347-352

Shaving Clipping and SSI

Cruse Arch Surg 1973 107 206

Infected

23

17

09

0

05

1

15

2

25

Shave Clip Neither

Fundamentals of Antibiotic Administration

Once the incision is madeantibiotic delivery to thewound is impairedMust give before incision

ABXABX

SSIs and Glucose Levels CTS pts

012345678

100ndash150 150ndash200 200ndash250 250ndash300Day 1 Blood Glucose (mgdL)

Dee

p In

fect

ion

Rat

e

Zerr KJ et al Glucose control lowers the risk of wound infection in diabetics after open heart operations page 360 Reprinted from The Annals of Thoracic Surgeons Vol 63

13 1625

67

P=0002

Glucose control (200 mgdl)decreases infection rate

Presenter
Presentation Notes
Elevated blood glucose levels after an operation are also associated with an increased risk of SSIs particularly in diabetic patients In an observational study Zerr and colleagues found a correlation between glucose levels immediately following surgery and the rate of deep sternal infection1 131313131313131313131313131313Reference131Zerr KJ Furnary AP Grunkemeier GL Bookins S Kanhere V Starr A Glucose control lowers the risk of wound infection in diabetics after open heart operations Ann Thorac Surg 199763356ndash36113

Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)

SENTRY ndash US and Canada 2000

Rennie RP et al Diagn Microbiol Infect Dis 200345287-293

N=1404 isolates

108 P aeruginosa

Enterococci 82

E coli 70

Enterobacter 58

Other 173 MSSA 309

MRSA ~15

Klebsiella 51

Presenter
Presentation Notes
In the SENTRY Antimicrobial Surveillance Program S aureus was found to be the predominant pathogen in nosocomial SSSIs MRSA was more prevalent than any other organism excluding methicillin-susceptible S aureus13S aureus accounted for 459 of isolates recovered from SSSIs among hospitalized patients at 24 sites in the United States and 5 sites in Canada between October and December 2000 Notably approximately 30 of S aureus isolates were methicillin (oxacillin)-resistant 13Other common pathogens isolated from SSSIs were P aeruginosa (108) Enterococcus spp (82) E coli (70) Enterobacter spp (58) and Klebsiella spp (51) The same rank order of pathogens in SSSIs was observed in both the United States and Canada

Microbiology Increasing proportion of

SSIs Antimicrobial-resistant

pathogensMRSAhelliphellip

Unusual pathogens Rhizopus oryzae Clostridium perfringens Rhodococcus bronchialis Nocardia farcinica Legionella pneumophila and

Legionella dumoffii Pseudomonas multivorans

From Weiss CA Statz CI Dahms RA et al Six years of surgical wound surveillance at a tertiary care center Arch Surg 1341041

Unusual pathogens of SSIs

bull Rhizopus oryzea ndashelastoplast adhesive bandage

bull Clostridium perfringens ndashelastic bandages

bull Rhodococcus bronchialis ndashcolonized health care personnel

bull Legionella dumoffii and pneumophila ndashtap water

bull Pseudomonas multivorans ndashdisinfectant solution

0

10

20

30

40

50

60

1975 87 88 89 90 91 92 93 94 95 96 97 98 99

2000

2002

Res

ista

nt is

olat

es (

)

CDC MMWR 199746624-628 635 (1975 data) Lowy FD N Engl J Med 1998339520-532 (1987-1997 data) CDC NNIS System Report JanuaryndashNovember 1998 (1998 data) CDC NNIS System Report January 1990ndashMay 1999 issued June 1999 Am J Infect

Progression of Methicillin Resistant S aureus ndash United States13uarr

571553

Presenter
Presentation Notes
MRSA was first described in the United Kingdom in 1961 MRSA rates were low in US hospitals reported at lt 2 in the 1970s and early 1980s 13Examination of the rates of methicillin resistance in S aureus isolates in the United States by the CDC documents that rates have increased steadily over the past decade with a dramatic 40 increase during the last 5-year historical mean In 2000 553 of the S aureus isolates associated with a hospital-acquired infection in ICU patients were resistant to methicillin reflecting a further 31 increase in resistant S aureus isolates during the past year More recently in 2002 571 of S aureus isolates were MRSA accounting for an increase of 13 from the previous year1313

1

2

Surgical sitebull Hematoma

bull Foreign bodies

bull Dead tissue

bull Dead space

Presenter
Presentation Notes
Page 7 - Iron and impermeability of clot - silk suture - electrocautery and ischemia - these are importanat because we can control them - other include burn trauma bites PVD poor hygiene drains

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 3: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

EPIDEMIOLOGYwound classification I Clean

II Clean contaminated

III Contaminated

IV Dirty procedures

skin andmusculoskeletal soft tissues

Hollow viscus hasbeen opened

Bacteria introduced to Sterile body cavity

To Control established Infections

Presenter
Presentation Notes
Issues related to bacterial contamination have been well defined Clean surgical procedures are those where operations has affected only integumentary and musculoskeletal soft tissues13Clean contaminated procedures are those where a hollow viscus eg alimentary biliary genitourinary has been opened under controlled circumstances elective colon surgery13Contaminated procedures are those where bacteria has been introduced into a normally sterile site eg penetrating abdominal trauma13Dirty procedures are those where surgery is performed to control established infection eg colon resection for complicated diverticulitis 13Traumatic wounds with retained devitalized tissue foreign bodies or fecal contamination perforated viscus acute purulent bacterial inflammation

Sabiston Textbook of Surgery 18th ed

NNIS risk index 0 to 3 points (1) American Society of Anesthesiologists (ASA)

Physical Status Classification of gt2 (2) Contaminated or dirtyinfected wound classification (3) length of operation gtT hours where T depends

upon the operative procedure being performed

Index 1 (0 points) 15Index 2 (one point) 29Index 3 (two points) 68Index 4 (three points) 13

Elective Surgical ProceduresHair RemovalClipping hair just before case is best

Hair Removal Method Infection Rate

PM Razor 52 - 88AM Razor 64 - 10PM Clipper 4 - 75AM Clipper 18 - 32

Alexander JW et al Arch Surg1983 118347-352

Shaving Clipping and SSI

Cruse Arch Surg 1973 107 206

Infected

23

17

09

0

05

1

15

2

25

Shave Clip Neither

Fundamentals of Antibiotic Administration

Once the incision is madeantibiotic delivery to thewound is impairedMust give before incision

ABXABX

SSIs and Glucose Levels CTS pts

012345678

100ndash150 150ndash200 200ndash250 250ndash300Day 1 Blood Glucose (mgdL)

Dee

p In

fect

ion

Rat

e

Zerr KJ et al Glucose control lowers the risk of wound infection in diabetics after open heart operations page 360 Reprinted from The Annals of Thoracic Surgeons Vol 63

13 1625

67

P=0002

Glucose control (200 mgdl)decreases infection rate

Presenter
Presentation Notes
Elevated blood glucose levels after an operation are also associated with an increased risk of SSIs particularly in diabetic patients In an observational study Zerr and colleagues found a correlation between glucose levels immediately following surgery and the rate of deep sternal infection1 131313131313131313131313131313Reference131Zerr KJ Furnary AP Grunkemeier GL Bookins S Kanhere V Starr A Glucose control lowers the risk of wound infection in diabetics after open heart operations Ann Thorac Surg 199763356ndash36113

Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)

SENTRY ndash US and Canada 2000

Rennie RP et al Diagn Microbiol Infect Dis 200345287-293

N=1404 isolates

108 P aeruginosa

Enterococci 82

E coli 70

Enterobacter 58

Other 173 MSSA 309

MRSA ~15

Klebsiella 51

Presenter
Presentation Notes
In the SENTRY Antimicrobial Surveillance Program S aureus was found to be the predominant pathogen in nosocomial SSSIs MRSA was more prevalent than any other organism excluding methicillin-susceptible S aureus13S aureus accounted for 459 of isolates recovered from SSSIs among hospitalized patients at 24 sites in the United States and 5 sites in Canada between October and December 2000 Notably approximately 30 of S aureus isolates were methicillin (oxacillin)-resistant 13Other common pathogens isolated from SSSIs were P aeruginosa (108) Enterococcus spp (82) E coli (70) Enterobacter spp (58) and Klebsiella spp (51) The same rank order of pathogens in SSSIs was observed in both the United States and Canada

Microbiology Increasing proportion of

SSIs Antimicrobial-resistant

pathogensMRSAhelliphellip

Unusual pathogens Rhizopus oryzae Clostridium perfringens Rhodococcus bronchialis Nocardia farcinica Legionella pneumophila and

Legionella dumoffii Pseudomonas multivorans

From Weiss CA Statz CI Dahms RA et al Six years of surgical wound surveillance at a tertiary care center Arch Surg 1341041

Unusual pathogens of SSIs

bull Rhizopus oryzea ndashelastoplast adhesive bandage

bull Clostridium perfringens ndashelastic bandages

bull Rhodococcus bronchialis ndashcolonized health care personnel

bull Legionella dumoffii and pneumophila ndashtap water

bull Pseudomonas multivorans ndashdisinfectant solution

0

10

20

30

40

50

60

1975 87 88 89 90 91 92 93 94 95 96 97 98 99

2000

2002

Res

ista

nt is

olat

es (

)

CDC MMWR 199746624-628 635 (1975 data) Lowy FD N Engl J Med 1998339520-532 (1987-1997 data) CDC NNIS System Report JanuaryndashNovember 1998 (1998 data) CDC NNIS System Report January 1990ndashMay 1999 issued June 1999 Am J Infect

Progression of Methicillin Resistant S aureus ndash United States13uarr

571553

Presenter
Presentation Notes
MRSA was first described in the United Kingdom in 1961 MRSA rates were low in US hospitals reported at lt 2 in the 1970s and early 1980s 13Examination of the rates of methicillin resistance in S aureus isolates in the United States by the CDC documents that rates have increased steadily over the past decade with a dramatic 40 increase during the last 5-year historical mean In 2000 553 of the S aureus isolates associated with a hospital-acquired infection in ICU patients were resistant to methicillin reflecting a further 31 increase in resistant S aureus isolates during the past year More recently in 2002 571 of S aureus isolates were MRSA accounting for an increase of 13 from the previous year1313

1

2

Surgical sitebull Hematoma

bull Foreign bodies

bull Dead tissue

bull Dead space

Presenter
Presentation Notes
Page 7 - Iron and impermeability of clot - silk suture - electrocautery and ischemia - these are importanat because we can control them - other include burn trauma bites PVD poor hygiene drains

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
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  • EPIDEMIOLOGYwound classification
  • Slide Number 17
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  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
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  • Slide Number 43
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  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
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  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
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  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
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Page 4: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Sabiston Textbook of Surgery 18th ed

NNIS risk index 0 to 3 points (1) American Society of Anesthesiologists (ASA)

Physical Status Classification of gt2 (2) Contaminated or dirtyinfected wound classification (3) length of operation gtT hours where T depends

upon the operative procedure being performed

Index 1 (0 points) 15Index 2 (one point) 29Index 3 (two points) 68Index 4 (three points) 13

Elective Surgical ProceduresHair RemovalClipping hair just before case is best

Hair Removal Method Infection Rate

PM Razor 52 - 88AM Razor 64 - 10PM Clipper 4 - 75AM Clipper 18 - 32

Alexander JW et al Arch Surg1983 118347-352

Shaving Clipping and SSI

Cruse Arch Surg 1973 107 206

Infected

23

17

09

0

05

1

15

2

25

Shave Clip Neither

Fundamentals of Antibiotic Administration

Once the incision is madeantibiotic delivery to thewound is impairedMust give before incision

ABXABX

SSIs and Glucose Levels CTS pts

012345678

100ndash150 150ndash200 200ndash250 250ndash300Day 1 Blood Glucose (mgdL)

Dee

p In

fect

ion

Rat

e

Zerr KJ et al Glucose control lowers the risk of wound infection in diabetics after open heart operations page 360 Reprinted from The Annals of Thoracic Surgeons Vol 63

13 1625

67

P=0002

Glucose control (200 mgdl)decreases infection rate

Presenter
Presentation Notes
Elevated blood glucose levels after an operation are also associated with an increased risk of SSIs particularly in diabetic patients In an observational study Zerr and colleagues found a correlation between glucose levels immediately following surgery and the rate of deep sternal infection1 131313131313131313131313131313Reference131Zerr KJ Furnary AP Grunkemeier GL Bookins S Kanhere V Starr A Glucose control lowers the risk of wound infection in diabetics after open heart operations Ann Thorac Surg 199763356ndash36113

Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)

SENTRY ndash US and Canada 2000

Rennie RP et al Diagn Microbiol Infect Dis 200345287-293

N=1404 isolates

108 P aeruginosa

Enterococci 82

E coli 70

Enterobacter 58

Other 173 MSSA 309

MRSA ~15

Klebsiella 51

Presenter
Presentation Notes
In the SENTRY Antimicrobial Surveillance Program S aureus was found to be the predominant pathogen in nosocomial SSSIs MRSA was more prevalent than any other organism excluding methicillin-susceptible S aureus13S aureus accounted for 459 of isolates recovered from SSSIs among hospitalized patients at 24 sites in the United States and 5 sites in Canada between October and December 2000 Notably approximately 30 of S aureus isolates were methicillin (oxacillin)-resistant 13Other common pathogens isolated from SSSIs were P aeruginosa (108) Enterococcus spp (82) E coli (70) Enterobacter spp (58) and Klebsiella spp (51) The same rank order of pathogens in SSSIs was observed in both the United States and Canada

Microbiology Increasing proportion of

SSIs Antimicrobial-resistant

pathogensMRSAhelliphellip

Unusual pathogens Rhizopus oryzae Clostridium perfringens Rhodococcus bronchialis Nocardia farcinica Legionella pneumophila and

Legionella dumoffii Pseudomonas multivorans

From Weiss CA Statz CI Dahms RA et al Six years of surgical wound surveillance at a tertiary care center Arch Surg 1341041

Unusual pathogens of SSIs

bull Rhizopus oryzea ndashelastoplast adhesive bandage

bull Clostridium perfringens ndashelastic bandages

bull Rhodococcus bronchialis ndashcolonized health care personnel

bull Legionella dumoffii and pneumophila ndashtap water

bull Pseudomonas multivorans ndashdisinfectant solution

0

10

20

30

40

50

60

1975 87 88 89 90 91 92 93 94 95 96 97 98 99

2000

2002

Res

ista

nt is

olat

es (

)

CDC MMWR 199746624-628 635 (1975 data) Lowy FD N Engl J Med 1998339520-532 (1987-1997 data) CDC NNIS System Report JanuaryndashNovember 1998 (1998 data) CDC NNIS System Report January 1990ndashMay 1999 issued June 1999 Am J Infect

Progression of Methicillin Resistant S aureus ndash United States13uarr

571553

Presenter
Presentation Notes
MRSA was first described in the United Kingdom in 1961 MRSA rates were low in US hospitals reported at lt 2 in the 1970s and early 1980s 13Examination of the rates of methicillin resistance in S aureus isolates in the United States by the CDC documents that rates have increased steadily over the past decade with a dramatic 40 increase during the last 5-year historical mean In 2000 553 of the S aureus isolates associated with a hospital-acquired infection in ICU patients were resistant to methicillin reflecting a further 31 increase in resistant S aureus isolates during the past year More recently in 2002 571 of S aureus isolates were MRSA accounting for an increase of 13 from the previous year1313

1

2

Surgical sitebull Hematoma

bull Foreign bodies

bull Dead tissue

bull Dead space

Presenter
Presentation Notes
Page 7 - Iron and impermeability of clot - silk suture - electrocautery and ischemia - these are importanat because we can control them - other include burn trauma bites PVD poor hygiene drains

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 5: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

NNIS risk index 0 to 3 points (1) American Society of Anesthesiologists (ASA)

Physical Status Classification of gt2 (2) Contaminated or dirtyinfected wound classification (3) length of operation gtT hours where T depends

upon the operative procedure being performed

Index 1 (0 points) 15Index 2 (one point) 29Index 3 (two points) 68Index 4 (three points) 13

Elective Surgical ProceduresHair RemovalClipping hair just before case is best

Hair Removal Method Infection Rate

PM Razor 52 - 88AM Razor 64 - 10PM Clipper 4 - 75AM Clipper 18 - 32

Alexander JW et al Arch Surg1983 118347-352

Shaving Clipping and SSI

Cruse Arch Surg 1973 107 206

Infected

23

17

09

0

05

1

15

2

25

Shave Clip Neither

Fundamentals of Antibiotic Administration

Once the incision is madeantibiotic delivery to thewound is impairedMust give before incision

ABXABX

SSIs and Glucose Levels CTS pts

012345678

100ndash150 150ndash200 200ndash250 250ndash300Day 1 Blood Glucose (mgdL)

Dee

p In

fect

ion

Rat

e

Zerr KJ et al Glucose control lowers the risk of wound infection in diabetics after open heart operations page 360 Reprinted from The Annals of Thoracic Surgeons Vol 63

13 1625

67

P=0002

Glucose control (200 mgdl)decreases infection rate

Presenter
Presentation Notes
Elevated blood glucose levels after an operation are also associated with an increased risk of SSIs particularly in diabetic patients In an observational study Zerr and colleagues found a correlation between glucose levels immediately following surgery and the rate of deep sternal infection1 131313131313131313131313131313Reference131Zerr KJ Furnary AP Grunkemeier GL Bookins S Kanhere V Starr A Glucose control lowers the risk of wound infection in diabetics after open heart operations Ann Thorac Surg 199763356ndash36113

Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)

SENTRY ndash US and Canada 2000

Rennie RP et al Diagn Microbiol Infect Dis 200345287-293

N=1404 isolates

108 P aeruginosa

Enterococci 82

E coli 70

Enterobacter 58

Other 173 MSSA 309

MRSA ~15

Klebsiella 51

Presenter
Presentation Notes
In the SENTRY Antimicrobial Surveillance Program S aureus was found to be the predominant pathogen in nosocomial SSSIs MRSA was more prevalent than any other organism excluding methicillin-susceptible S aureus13S aureus accounted for 459 of isolates recovered from SSSIs among hospitalized patients at 24 sites in the United States and 5 sites in Canada between October and December 2000 Notably approximately 30 of S aureus isolates were methicillin (oxacillin)-resistant 13Other common pathogens isolated from SSSIs were P aeruginosa (108) Enterococcus spp (82) E coli (70) Enterobacter spp (58) and Klebsiella spp (51) The same rank order of pathogens in SSSIs was observed in both the United States and Canada

Microbiology Increasing proportion of

SSIs Antimicrobial-resistant

pathogensMRSAhelliphellip

Unusual pathogens Rhizopus oryzae Clostridium perfringens Rhodococcus bronchialis Nocardia farcinica Legionella pneumophila and

Legionella dumoffii Pseudomonas multivorans

From Weiss CA Statz CI Dahms RA et al Six years of surgical wound surveillance at a tertiary care center Arch Surg 1341041

Unusual pathogens of SSIs

bull Rhizopus oryzea ndashelastoplast adhesive bandage

bull Clostridium perfringens ndashelastic bandages

bull Rhodococcus bronchialis ndashcolonized health care personnel

bull Legionella dumoffii and pneumophila ndashtap water

bull Pseudomonas multivorans ndashdisinfectant solution

0

10

20

30

40

50

60

1975 87 88 89 90 91 92 93 94 95 96 97 98 99

2000

2002

Res

ista

nt is

olat

es (

)

CDC MMWR 199746624-628 635 (1975 data) Lowy FD N Engl J Med 1998339520-532 (1987-1997 data) CDC NNIS System Report JanuaryndashNovember 1998 (1998 data) CDC NNIS System Report January 1990ndashMay 1999 issued June 1999 Am J Infect

Progression of Methicillin Resistant S aureus ndash United States13uarr

571553

Presenter
Presentation Notes
MRSA was first described in the United Kingdom in 1961 MRSA rates were low in US hospitals reported at lt 2 in the 1970s and early 1980s 13Examination of the rates of methicillin resistance in S aureus isolates in the United States by the CDC documents that rates have increased steadily over the past decade with a dramatic 40 increase during the last 5-year historical mean In 2000 553 of the S aureus isolates associated with a hospital-acquired infection in ICU patients were resistant to methicillin reflecting a further 31 increase in resistant S aureus isolates during the past year More recently in 2002 571 of S aureus isolates were MRSA accounting for an increase of 13 from the previous year1313

1

2

Surgical sitebull Hematoma

bull Foreign bodies

bull Dead tissue

bull Dead space

Presenter
Presentation Notes
Page 7 - Iron and impermeability of clot - silk suture - electrocautery and ischemia - these are importanat because we can control them - other include burn trauma bites PVD poor hygiene drains

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

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  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
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  • EPIDEMIOLOGYwound classification
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  • Elective Surgical ProceduresHair Removal
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  • Shaving Clipping and SSI
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  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
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  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
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  • Surgical site
  • Slide Number 89
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  • Pathogenesis of SSI
  • Slide Number 95
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  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
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  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
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  • Work up any potential pathogens to maximum of three
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  • Workup of Wound Cultures
  • Workup of Wound Cultures
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Page 6: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Elective Surgical ProceduresHair RemovalClipping hair just before case is best

Hair Removal Method Infection Rate

PM Razor 52 - 88AM Razor 64 - 10PM Clipper 4 - 75AM Clipper 18 - 32

Alexander JW et al Arch Surg1983 118347-352

Shaving Clipping and SSI

Cruse Arch Surg 1973 107 206

Infected

23

17

09

0

05

1

15

2

25

Shave Clip Neither

Fundamentals of Antibiotic Administration

Once the incision is madeantibiotic delivery to thewound is impairedMust give before incision

ABXABX

SSIs and Glucose Levels CTS pts

012345678

100ndash150 150ndash200 200ndash250 250ndash300Day 1 Blood Glucose (mgdL)

Dee

p In

fect

ion

Rat

e

Zerr KJ et al Glucose control lowers the risk of wound infection in diabetics after open heart operations page 360 Reprinted from The Annals of Thoracic Surgeons Vol 63

13 1625

67

P=0002

Glucose control (200 mgdl)decreases infection rate

Presenter
Presentation Notes
Elevated blood glucose levels after an operation are also associated with an increased risk of SSIs particularly in diabetic patients In an observational study Zerr and colleagues found a correlation between glucose levels immediately following surgery and the rate of deep sternal infection1 131313131313131313131313131313Reference131Zerr KJ Furnary AP Grunkemeier GL Bookins S Kanhere V Starr A Glucose control lowers the risk of wound infection in diabetics after open heart operations Ann Thorac Surg 199763356ndash36113

Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)

SENTRY ndash US and Canada 2000

Rennie RP et al Diagn Microbiol Infect Dis 200345287-293

N=1404 isolates

108 P aeruginosa

Enterococci 82

E coli 70

Enterobacter 58

Other 173 MSSA 309

MRSA ~15

Klebsiella 51

Presenter
Presentation Notes
In the SENTRY Antimicrobial Surveillance Program S aureus was found to be the predominant pathogen in nosocomial SSSIs MRSA was more prevalent than any other organism excluding methicillin-susceptible S aureus13S aureus accounted for 459 of isolates recovered from SSSIs among hospitalized patients at 24 sites in the United States and 5 sites in Canada between October and December 2000 Notably approximately 30 of S aureus isolates were methicillin (oxacillin)-resistant 13Other common pathogens isolated from SSSIs were P aeruginosa (108) Enterococcus spp (82) E coli (70) Enterobacter spp (58) and Klebsiella spp (51) The same rank order of pathogens in SSSIs was observed in both the United States and Canada

Microbiology Increasing proportion of

SSIs Antimicrobial-resistant

pathogensMRSAhelliphellip

Unusual pathogens Rhizopus oryzae Clostridium perfringens Rhodococcus bronchialis Nocardia farcinica Legionella pneumophila and

Legionella dumoffii Pseudomonas multivorans

From Weiss CA Statz CI Dahms RA et al Six years of surgical wound surveillance at a tertiary care center Arch Surg 1341041

Unusual pathogens of SSIs

bull Rhizopus oryzea ndashelastoplast adhesive bandage

bull Clostridium perfringens ndashelastic bandages

bull Rhodococcus bronchialis ndashcolonized health care personnel

bull Legionella dumoffii and pneumophila ndashtap water

bull Pseudomonas multivorans ndashdisinfectant solution

0

10

20

30

40

50

60

1975 87 88 89 90 91 92 93 94 95 96 97 98 99

2000

2002

Res

ista

nt is

olat

es (

)

CDC MMWR 199746624-628 635 (1975 data) Lowy FD N Engl J Med 1998339520-532 (1987-1997 data) CDC NNIS System Report JanuaryndashNovember 1998 (1998 data) CDC NNIS System Report January 1990ndashMay 1999 issued June 1999 Am J Infect

Progression of Methicillin Resistant S aureus ndash United States13uarr

571553

Presenter
Presentation Notes
MRSA was first described in the United Kingdom in 1961 MRSA rates were low in US hospitals reported at lt 2 in the 1970s and early 1980s 13Examination of the rates of methicillin resistance in S aureus isolates in the United States by the CDC documents that rates have increased steadily over the past decade with a dramatic 40 increase during the last 5-year historical mean In 2000 553 of the S aureus isolates associated with a hospital-acquired infection in ICU patients were resistant to methicillin reflecting a further 31 increase in resistant S aureus isolates during the past year More recently in 2002 571 of S aureus isolates were MRSA accounting for an increase of 13 from the previous year1313

1

2

Surgical sitebull Hematoma

bull Foreign bodies

bull Dead tissue

bull Dead space

Presenter
Presentation Notes
Page 7 - Iron and impermeability of clot - silk suture - electrocautery and ischemia - these are importanat because we can control them - other include burn trauma bites PVD poor hygiene drains

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
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  • Slide Number 4
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  • Slide Number 10
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  • EPIDEMIOLOGYwound classification
  • Slide Number 17
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  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
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  • Slide Number 50
  • Slide Number 51
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  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
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  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 7: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Shaving Clipping and SSI

Cruse Arch Surg 1973 107 206

Infected

23

17

09

0

05

1

15

2

25

Shave Clip Neither

Fundamentals of Antibiotic Administration

Once the incision is madeantibiotic delivery to thewound is impairedMust give before incision

ABXABX

SSIs and Glucose Levels CTS pts

012345678

100ndash150 150ndash200 200ndash250 250ndash300Day 1 Blood Glucose (mgdL)

Dee

p In

fect

ion

Rat

e

Zerr KJ et al Glucose control lowers the risk of wound infection in diabetics after open heart operations page 360 Reprinted from The Annals of Thoracic Surgeons Vol 63

13 1625

67

P=0002

Glucose control (200 mgdl)decreases infection rate

Presenter
Presentation Notes
Elevated blood glucose levels after an operation are also associated with an increased risk of SSIs particularly in diabetic patients In an observational study Zerr and colleagues found a correlation between glucose levels immediately following surgery and the rate of deep sternal infection1 131313131313131313131313131313Reference131Zerr KJ Furnary AP Grunkemeier GL Bookins S Kanhere V Starr A Glucose control lowers the risk of wound infection in diabetics after open heart operations Ann Thorac Surg 199763356ndash36113

Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)

SENTRY ndash US and Canada 2000

Rennie RP et al Diagn Microbiol Infect Dis 200345287-293

N=1404 isolates

108 P aeruginosa

Enterococci 82

E coli 70

Enterobacter 58

Other 173 MSSA 309

MRSA ~15

Klebsiella 51

Presenter
Presentation Notes
In the SENTRY Antimicrobial Surveillance Program S aureus was found to be the predominant pathogen in nosocomial SSSIs MRSA was more prevalent than any other organism excluding methicillin-susceptible S aureus13S aureus accounted for 459 of isolates recovered from SSSIs among hospitalized patients at 24 sites in the United States and 5 sites in Canada between October and December 2000 Notably approximately 30 of S aureus isolates were methicillin (oxacillin)-resistant 13Other common pathogens isolated from SSSIs were P aeruginosa (108) Enterococcus spp (82) E coli (70) Enterobacter spp (58) and Klebsiella spp (51) The same rank order of pathogens in SSSIs was observed in both the United States and Canada

Microbiology Increasing proportion of

SSIs Antimicrobial-resistant

pathogensMRSAhelliphellip

Unusual pathogens Rhizopus oryzae Clostridium perfringens Rhodococcus bronchialis Nocardia farcinica Legionella pneumophila and

Legionella dumoffii Pseudomonas multivorans

From Weiss CA Statz CI Dahms RA et al Six years of surgical wound surveillance at a tertiary care center Arch Surg 1341041

Unusual pathogens of SSIs

bull Rhizopus oryzea ndashelastoplast adhesive bandage

bull Clostridium perfringens ndashelastic bandages

bull Rhodococcus bronchialis ndashcolonized health care personnel

bull Legionella dumoffii and pneumophila ndashtap water

bull Pseudomonas multivorans ndashdisinfectant solution

0

10

20

30

40

50

60

1975 87 88 89 90 91 92 93 94 95 96 97 98 99

2000

2002

Res

ista

nt is

olat

es (

)

CDC MMWR 199746624-628 635 (1975 data) Lowy FD N Engl J Med 1998339520-532 (1987-1997 data) CDC NNIS System Report JanuaryndashNovember 1998 (1998 data) CDC NNIS System Report January 1990ndashMay 1999 issued June 1999 Am J Infect

Progression of Methicillin Resistant S aureus ndash United States13uarr

571553

Presenter
Presentation Notes
MRSA was first described in the United Kingdom in 1961 MRSA rates were low in US hospitals reported at lt 2 in the 1970s and early 1980s 13Examination of the rates of methicillin resistance in S aureus isolates in the United States by the CDC documents that rates have increased steadily over the past decade with a dramatic 40 increase during the last 5-year historical mean In 2000 553 of the S aureus isolates associated with a hospital-acquired infection in ICU patients were resistant to methicillin reflecting a further 31 increase in resistant S aureus isolates during the past year More recently in 2002 571 of S aureus isolates were MRSA accounting for an increase of 13 from the previous year1313

1

2

Surgical sitebull Hematoma

bull Foreign bodies

bull Dead tissue

bull Dead space

Presenter
Presentation Notes
Page 7 - Iron and impermeability of clot - silk suture - electrocautery and ischemia - these are importanat because we can control them - other include burn trauma bites PVD poor hygiene drains

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 8: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Fundamentals of Antibiotic Administration

Once the incision is madeantibiotic delivery to thewound is impairedMust give before incision

ABXABX

SSIs and Glucose Levels CTS pts

012345678

100ndash150 150ndash200 200ndash250 250ndash300Day 1 Blood Glucose (mgdL)

Dee

p In

fect

ion

Rat

e

Zerr KJ et al Glucose control lowers the risk of wound infection in diabetics after open heart operations page 360 Reprinted from The Annals of Thoracic Surgeons Vol 63

13 1625

67

P=0002

Glucose control (200 mgdl)decreases infection rate

Presenter
Presentation Notes
Elevated blood glucose levels after an operation are also associated with an increased risk of SSIs particularly in diabetic patients In an observational study Zerr and colleagues found a correlation between glucose levels immediately following surgery and the rate of deep sternal infection1 131313131313131313131313131313Reference131Zerr KJ Furnary AP Grunkemeier GL Bookins S Kanhere V Starr A Glucose control lowers the risk of wound infection in diabetics after open heart operations Ann Thorac Surg 199763356ndash36113

Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)

SENTRY ndash US and Canada 2000

Rennie RP et al Diagn Microbiol Infect Dis 200345287-293

N=1404 isolates

108 P aeruginosa

Enterococci 82

E coli 70

Enterobacter 58

Other 173 MSSA 309

MRSA ~15

Klebsiella 51

Presenter
Presentation Notes
In the SENTRY Antimicrobial Surveillance Program S aureus was found to be the predominant pathogen in nosocomial SSSIs MRSA was more prevalent than any other organism excluding methicillin-susceptible S aureus13S aureus accounted for 459 of isolates recovered from SSSIs among hospitalized patients at 24 sites in the United States and 5 sites in Canada between October and December 2000 Notably approximately 30 of S aureus isolates were methicillin (oxacillin)-resistant 13Other common pathogens isolated from SSSIs were P aeruginosa (108) Enterococcus spp (82) E coli (70) Enterobacter spp (58) and Klebsiella spp (51) The same rank order of pathogens in SSSIs was observed in both the United States and Canada

Microbiology Increasing proportion of

SSIs Antimicrobial-resistant

pathogensMRSAhelliphellip

Unusual pathogens Rhizopus oryzae Clostridium perfringens Rhodococcus bronchialis Nocardia farcinica Legionella pneumophila and

Legionella dumoffii Pseudomonas multivorans

From Weiss CA Statz CI Dahms RA et al Six years of surgical wound surveillance at a tertiary care center Arch Surg 1341041

Unusual pathogens of SSIs

bull Rhizopus oryzea ndashelastoplast adhesive bandage

bull Clostridium perfringens ndashelastic bandages

bull Rhodococcus bronchialis ndashcolonized health care personnel

bull Legionella dumoffii and pneumophila ndashtap water

bull Pseudomonas multivorans ndashdisinfectant solution

0

10

20

30

40

50

60

1975 87 88 89 90 91 92 93 94 95 96 97 98 99

2000

2002

Res

ista

nt is

olat

es (

)

CDC MMWR 199746624-628 635 (1975 data) Lowy FD N Engl J Med 1998339520-532 (1987-1997 data) CDC NNIS System Report JanuaryndashNovember 1998 (1998 data) CDC NNIS System Report January 1990ndashMay 1999 issued June 1999 Am J Infect

Progression of Methicillin Resistant S aureus ndash United States13uarr

571553

Presenter
Presentation Notes
MRSA was first described in the United Kingdom in 1961 MRSA rates were low in US hospitals reported at lt 2 in the 1970s and early 1980s 13Examination of the rates of methicillin resistance in S aureus isolates in the United States by the CDC documents that rates have increased steadily over the past decade with a dramatic 40 increase during the last 5-year historical mean In 2000 553 of the S aureus isolates associated with a hospital-acquired infection in ICU patients were resistant to methicillin reflecting a further 31 increase in resistant S aureus isolates during the past year More recently in 2002 571 of S aureus isolates were MRSA accounting for an increase of 13 from the previous year1313

1

2

Surgical sitebull Hematoma

bull Foreign bodies

bull Dead tissue

bull Dead space

Presenter
Presentation Notes
Page 7 - Iron and impermeability of clot - silk suture - electrocautery and ischemia - these are importanat because we can control them - other include burn trauma bites PVD poor hygiene drains

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
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  • EPIDEMIOLOGYwound classification
  • Slide Number 17
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  • Slide Number 33
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  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
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  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
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  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
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  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
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  • Slide Number 106
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  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
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Page 9: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

SSIs and Glucose Levels CTS pts

012345678

100ndash150 150ndash200 200ndash250 250ndash300Day 1 Blood Glucose (mgdL)

Dee

p In

fect

ion

Rat

e

Zerr KJ et al Glucose control lowers the risk of wound infection in diabetics after open heart operations page 360 Reprinted from The Annals of Thoracic Surgeons Vol 63

13 1625

67

P=0002

Glucose control (200 mgdl)decreases infection rate

Presenter
Presentation Notes
Elevated blood glucose levels after an operation are also associated with an increased risk of SSIs particularly in diabetic patients In an observational study Zerr and colleagues found a correlation between glucose levels immediately following surgery and the rate of deep sternal infection1 131313131313131313131313131313Reference131Zerr KJ Furnary AP Grunkemeier GL Bookins S Kanhere V Starr A Glucose control lowers the risk of wound infection in diabetics after open heart operations Ann Thorac Surg 199763356ndash36113

Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)

SENTRY ndash US and Canada 2000

Rennie RP et al Diagn Microbiol Infect Dis 200345287-293

N=1404 isolates

108 P aeruginosa

Enterococci 82

E coli 70

Enterobacter 58

Other 173 MSSA 309

MRSA ~15

Klebsiella 51

Presenter
Presentation Notes
In the SENTRY Antimicrobial Surveillance Program S aureus was found to be the predominant pathogen in nosocomial SSSIs MRSA was more prevalent than any other organism excluding methicillin-susceptible S aureus13S aureus accounted for 459 of isolates recovered from SSSIs among hospitalized patients at 24 sites in the United States and 5 sites in Canada between October and December 2000 Notably approximately 30 of S aureus isolates were methicillin (oxacillin)-resistant 13Other common pathogens isolated from SSSIs were P aeruginosa (108) Enterococcus spp (82) E coli (70) Enterobacter spp (58) and Klebsiella spp (51) The same rank order of pathogens in SSSIs was observed in both the United States and Canada

Microbiology Increasing proportion of

SSIs Antimicrobial-resistant

pathogensMRSAhelliphellip

Unusual pathogens Rhizopus oryzae Clostridium perfringens Rhodococcus bronchialis Nocardia farcinica Legionella pneumophila and

Legionella dumoffii Pseudomonas multivorans

From Weiss CA Statz CI Dahms RA et al Six years of surgical wound surveillance at a tertiary care center Arch Surg 1341041

Unusual pathogens of SSIs

bull Rhizopus oryzea ndashelastoplast adhesive bandage

bull Clostridium perfringens ndashelastic bandages

bull Rhodococcus bronchialis ndashcolonized health care personnel

bull Legionella dumoffii and pneumophila ndashtap water

bull Pseudomonas multivorans ndashdisinfectant solution

0

10

20

30

40

50

60

1975 87 88 89 90 91 92 93 94 95 96 97 98 99

2000

2002

Res

ista

nt is

olat

es (

)

CDC MMWR 199746624-628 635 (1975 data) Lowy FD N Engl J Med 1998339520-532 (1987-1997 data) CDC NNIS System Report JanuaryndashNovember 1998 (1998 data) CDC NNIS System Report January 1990ndashMay 1999 issued June 1999 Am J Infect

Progression of Methicillin Resistant S aureus ndash United States13uarr

571553

Presenter
Presentation Notes
MRSA was first described in the United Kingdom in 1961 MRSA rates were low in US hospitals reported at lt 2 in the 1970s and early 1980s 13Examination of the rates of methicillin resistance in S aureus isolates in the United States by the CDC documents that rates have increased steadily over the past decade with a dramatic 40 increase during the last 5-year historical mean In 2000 553 of the S aureus isolates associated with a hospital-acquired infection in ICU patients were resistant to methicillin reflecting a further 31 increase in resistant S aureus isolates during the past year More recently in 2002 571 of S aureus isolates were MRSA accounting for an increase of 13 from the previous year1313

1

2

Surgical sitebull Hematoma

bull Foreign bodies

bull Dead tissue

bull Dead space

Presenter
Presentation Notes
Page 7 - Iron and impermeability of clot - silk suture - electrocautery and ischemia - these are importanat because we can control them - other include burn trauma bites PVD poor hygiene drains

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
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  • EPIDEMIOLOGYwound classification
  • Slide Number 17
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  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
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  • Shaving Clipping and SSI
  • Slide Number 41
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  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
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  • Surgical site
  • Slide Number 89
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  • Pathogenesis of SSI
  • Slide Number 95
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  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
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  • Slide Number 106
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  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 10: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)

SENTRY ndash US and Canada 2000

Rennie RP et al Diagn Microbiol Infect Dis 200345287-293

N=1404 isolates

108 P aeruginosa

Enterococci 82

E coli 70

Enterobacter 58

Other 173 MSSA 309

MRSA ~15

Klebsiella 51

Presenter
Presentation Notes
In the SENTRY Antimicrobial Surveillance Program S aureus was found to be the predominant pathogen in nosocomial SSSIs MRSA was more prevalent than any other organism excluding methicillin-susceptible S aureus13S aureus accounted for 459 of isolates recovered from SSSIs among hospitalized patients at 24 sites in the United States and 5 sites in Canada between October and December 2000 Notably approximately 30 of S aureus isolates were methicillin (oxacillin)-resistant 13Other common pathogens isolated from SSSIs were P aeruginosa (108) Enterococcus spp (82) E coli (70) Enterobacter spp (58) and Klebsiella spp (51) The same rank order of pathogens in SSSIs was observed in both the United States and Canada

Microbiology Increasing proportion of

SSIs Antimicrobial-resistant

pathogensMRSAhelliphellip

Unusual pathogens Rhizopus oryzae Clostridium perfringens Rhodococcus bronchialis Nocardia farcinica Legionella pneumophila and

Legionella dumoffii Pseudomonas multivorans

From Weiss CA Statz CI Dahms RA et al Six years of surgical wound surveillance at a tertiary care center Arch Surg 1341041

Unusual pathogens of SSIs

bull Rhizopus oryzea ndashelastoplast adhesive bandage

bull Clostridium perfringens ndashelastic bandages

bull Rhodococcus bronchialis ndashcolonized health care personnel

bull Legionella dumoffii and pneumophila ndashtap water

bull Pseudomonas multivorans ndashdisinfectant solution

0

10

20

30

40

50

60

1975 87 88 89 90 91 92 93 94 95 96 97 98 99

2000

2002

Res

ista

nt is

olat

es (

)

CDC MMWR 199746624-628 635 (1975 data) Lowy FD N Engl J Med 1998339520-532 (1987-1997 data) CDC NNIS System Report JanuaryndashNovember 1998 (1998 data) CDC NNIS System Report January 1990ndashMay 1999 issued June 1999 Am J Infect

Progression of Methicillin Resistant S aureus ndash United States13uarr

571553

Presenter
Presentation Notes
MRSA was first described in the United Kingdom in 1961 MRSA rates were low in US hospitals reported at lt 2 in the 1970s and early 1980s 13Examination of the rates of methicillin resistance in S aureus isolates in the United States by the CDC documents that rates have increased steadily over the past decade with a dramatic 40 increase during the last 5-year historical mean In 2000 553 of the S aureus isolates associated with a hospital-acquired infection in ICU patients were resistant to methicillin reflecting a further 31 increase in resistant S aureus isolates during the past year More recently in 2002 571 of S aureus isolates were MRSA accounting for an increase of 13 from the previous year1313

1

2

Surgical sitebull Hematoma

bull Foreign bodies

bull Dead tissue

bull Dead space

Presenter
Presentation Notes
Page 7 - Iron and impermeability of clot - silk suture - electrocautery and ischemia - these are importanat because we can control them - other include burn trauma bites PVD poor hygiene drains

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
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  • Slide Number 5
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  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 11: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Microbiology Increasing proportion of

SSIs Antimicrobial-resistant

pathogensMRSAhelliphellip

Unusual pathogens Rhizopus oryzae Clostridium perfringens Rhodococcus bronchialis Nocardia farcinica Legionella pneumophila and

Legionella dumoffii Pseudomonas multivorans

From Weiss CA Statz CI Dahms RA et al Six years of surgical wound surveillance at a tertiary care center Arch Surg 1341041

Unusual pathogens of SSIs

bull Rhizopus oryzea ndashelastoplast adhesive bandage

bull Clostridium perfringens ndashelastic bandages

bull Rhodococcus bronchialis ndashcolonized health care personnel

bull Legionella dumoffii and pneumophila ndashtap water

bull Pseudomonas multivorans ndashdisinfectant solution

0

10

20

30

40

50

60

1975 87 88 89 90 91 92 93 94 95 96 97 98 99

2000

2002

Res

ista

nt is

olat

es (

)

CDC MMWR 199746624-628 635 (1975 data) Lowy FD N Engl J Med 1998339520-532 (1987-1997 data) CDC NNIS System Report JanuaryndashNovember 1998 (1998 data) CDC NNIS System Report January 1990ndashMay 1999 issued June 1999 Am J Infect

Progression of Methicillin Resistant S aureus ndash United States13uarr

571553

Presenter
Presentation Notes
MRSA was first described in the United Kingdom in 1961 MRSA rates were low in US hospitals reported at lt 2 in the 1970s and early 1980s 13Examination of the rates of methicillin resistance in S aureus isolates in the United States by the CDC documents that rates have increased steadily over the past decade with a dramatic 40 increase during the last 5-year historical mean In 2000 553 of the S aureus isolates associated with a hospital-acquired infection in ICU patients were resistant to methicillin reflecting a further 31 increase in resistant S aureus isolates during the past year More recently in 2002 571 of S aureus isolates were MRSA accounting for an increase of 13 from the previous year1313

1

2

Surgical sitebull Hematoma

bull Foreign bodies

bull Dead tissue

bull Dead space

Presenter
Presentation Notes
Page 7 - Iron and impermeability of clot - silk suture - electrocautery and ischemia - these are importanat because we can control them - other include burn trauma bites PVD poor hygiene drains

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 12: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Unusual pathogens of SSIs

bull Rhizopus oryzea ndashelastoplast adhesive bandage

bull Clostridium perfringens ndashelastic bandages

bull Rhodococcus bronchialis ndashcolonized health care personnel

bull Legionella dumoffii and pneumophila ndashtap water

bull Pseudomonas multivorans ndashdisinfectant solution

0

10

20

30

40

50

60

1975 87 88 89 90 91 92 93 94 95 96 97 98 99

2000

2002

Res

ista

nt is

olat

es (

)

CDC MMWR 199746624-628 635 (1975 data) Lowy FD N Engl J Med 1998339520-532 (1987-1997 data) CDC NNIS System Report JanuaryndashNovember 1998 (1998 data) CDC NNIS System Report January 1990ndashMay 1999 issued June 1999 Am J Infect

Progression of Methicillin Resistant S aureus ndash United States13uarr

571553

Presenter
Presentation Notes
MRSA was first described in the United Kingdom in 1961 MRSA rates were low in US hospitals reported at lt 2 in the 1970s and early 1980s 13Examination of the rates of methicillin resistance in S aureus isolates in the United States by the CDC documents that rates have increased steadily over the past decade with a dramatic 40 increase during the last 5-year historical mean In 2000 553 of the S aureus isolates associated with a hospital-acquired infection in ICU patients were resistant to methicillin reflecting a further 31 increase in resistant S aureus isolates during the past year More recently in 2002 571 of S aureus isolates were MRSA accounting for an increase of 13 from the previous year1313

1

2

Surgical sitebull Hematoma

bull Foreign bodies

bull Dead tissue

bull Dead space

Presenter
Presentation Notes
Page 7 - Iron and impermeability of clot - silk suture - electrocautery and ischemia - these are importanat because we can control them - other include burn trauma bites PVD poor hygiene drains

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
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  • EPIDEMIOLOGYwound classification
  • Slide Number 17
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  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
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  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
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  • Surgical site
  • Slide Number 89
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  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
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  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
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  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 13: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

0

10

20

30

40

50

60

1975 87 88 89 90 91 92 93 94 95 96 97 98 99

2000

2002

Res

ista

nt is

olat

es (

)

CDC MMWR 199746624-628 635 (1975 data) Lowy FD N Engl J Med 1998339520-532 (1987-1997 data) CDC NNIS System Report JanuaryndashNovember 1998 (1998 data) CDC NNIS System Report January 1990ndashMay 1999 issued June 1999 Am J Infect

Progression of Methicillin Resistant S aureus ndash United States13uarr

571553

Presenter
Presentation Notes
MRSA was first described in the United Kingdom in 1961 MRSA rates were low in US hospitals reported at lt 2 in the 1970s and early 1980s 13Examination of the rates of methicillin resistance in S aureus isolates in the United States by the CDC documents that rates have increased steadily over the past decade with a dramatic 40 increase during the last 5-year historical mean In 2000 553 of the S aureus isolates associated with a hospital-acquired infection in ICU patients were resistant to methicillin reflecting a further 31 increase in resistant S aureus isolates during the past year More recently in 2002 571 of S aureus isolates were MRSA accounting for an increase of 13 from the previous year1313

1

2

Surgical sitebull Hematoma

bull Foreign bodies

bull Dead tissue

bull Dead space

Presenter
Presentation Notes
Page 7 - Iron and impermeability of clot - silk suture - electrocautery and ischemia - these are importanat because we can control them - other include burn trauma bites PVD poor hygiene drains

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 14: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

1

2

Surgical sitebull Hematoma

bull Foreign bodies

bull Dead tissue

bull Dead space

Presenter
Presentation Notes
Page 7 - Iron and impermeability of clot - silk suture - electrocautery and ischemia - these are importanat because we can control them - other include burn trauma bites PVD poor hygiene drains

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 15: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Surgical sitebull Hematoma

bull Foreign bodies

bull Dead tissue

bull Dead space

Presenter
Presentation Notes
Page 7 - Iron and impermeability of clot - silk suture - electrocautery and ischemia - these are importanat because we can control them - other include burn trauma bites PVD poor hygiene drains

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
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  • Slide Number 13
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  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
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  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
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  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
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  • Slide Number 77
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  • Slide Number 82
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  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 16: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Pathogenesis of SSI

bull Relationship equation

Dose of bacterial contamination x VirulenceResistance of host

SSI Risk

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
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  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
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  • Slide Number 21
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  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
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  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
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  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 17: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Microbiology of SSIs

Staphylococcusaureus

17

Coagulase negstaphylococci

12

Escherichiacoli10

Enterococcusspp8

Pseudomonasaeruginosa

8

Staphylococcusaureus

20

Coagulase negstaphylococci

14

Escherichiacoli8

Enterococcusspp12

Pseudomonasaeruginosa

8

1986-1989(N=16727)

1990-1996(N=17671)

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 18: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

required for saving required for completionFacility ID Event Patient ID Social Security Secondary IDPatient Name Last First MiddleGender F M Date of BirthEthnicity (Specify) Race (Specify)Event Type SSI Date of EventDate of Procedure NHSN Procedure CodeICD-9-CM Procedure Code Outpatient Yes No MDRO Infection Yes NoDate Admitted to Facility LocationEvent Details

Specific Event Superficial Incisional Primary (SIP)

Superficial Incisional Secondary (SIS)

OrganSpace (specify site) ______________

Deep Incisional Primary (DIP)

Deep Incisional Secondary (DIS)

Specify Criteria Used (check all that apply)Signs amp Symptoms Purulent drainage or material Pain or tenderness Localized swelling Redness Heat Fever Incision deliberately opened by surgeon Wound spontaneously dehisces Abscess Hypothermia Apnea Bradycardia Lethargy Cough Nausea Vomiting Dysuria Other evidence of infection found on direct

exam during surgery or by diagnostic testsDagger

Other signs amp symptomsDagger

Laboratory Positive culture

Not cultured

Positive blood culture

Blood culture not done or no organisms detected inblood

Positive Gram stain when culture is negative or not done

Other positive laboratory testsDagger

Radiographic evidence of infection

Clinical Diagnosis Physician diagnosis of this event type

Physician institutes appropriate antimicrobialtherapyDagger

Daggerper organspace specific site criteria

Surgical Site Infection (SSI) Page 1 of 3

OMB No 0920-0666Exp Date 03-31-2011

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
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  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
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  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
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  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
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  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 19: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Drug CodesAMK = amikacinAMP = ampicillinAMPSUL=ampicillinsulbactamCEFEP = cefepimeCEFOX- cefoxitin

CEFOT = cefotaximeCEFTAZ = ceftazidimeCEFTRX = ceftriaxone CIPRO = ciprofloxacinCLIND = clindamycin

DAPTO=daptomycin ERYTH=erythromycinGENT=gentamicinIMI = imipenemLEVO = levofloxacin

LNZ = linezolid MERO = meropenemOX = oxacillinPENG = penicillin GPIP = piperacillin

PIPTAZ = piperacillintazobactamQUIDAL= quinupristindalfopristinRIF = rifampinTMZ =trimethoprimsulfamethoxazoleTOBRA = tobramycinVANC = vancomycin

Pathogen Gram-positive Organisms

_____Coagulase-negativestaphylococci

VANCS I R N

_____Enterococcusfaecalis

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

VANCS I R N

_____Enterococcusfaecium

AMPS I R N

DAPTOS I R N

LNZS I R N

PENGS I R N

QUIDALS I R N

VANCS I R N

_____Staphylococcusaureus

CEFOXS I R N

CLINDS I R N

DAPTOS I R N

ERYTHS I R N

GENTS I R N

LNZS I R N

OXS I R N

QUIDALS I R N

RIF S I R N

TMZS I R N

VANCS I R N

Pathogen Gram-negative Organisms

_____Acinetobacterspp (specify)__________

AMKS I R N

AMPSULS I R N

CEFEPS I R N

CEFTAZS I R N

CIPRO GENTS I R N S I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPTAZ TOBRA S I R N S I R N

_____Escherichia coli

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____

Enterobacterspp (specify)__________

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiellaoxytoca

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Klebsiella pneumoniae

AMKS I R N

CEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Serratia marcescens AMK

S I R NCEFEPS I R N

CEFOTS I R N

CEFTAZS I R N

CEFTRXS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

_____Pseudomonas aeruginosa

AMKS I R N

CEFEPS I R N

CEFTAZS I R N

CIPROS I R N

IMIS I R N

LEVOS I R N

MEROS I R N

PIPS I R N

_____Stenotrophomonas maltophilia

TMZS I R N

Pathogen Other Organisms

_____Organism 1(specify)__________________

____Drug 1S I R N

____Drug 2S I R N

____Drug 3S I R N

____Drug 4S I R N

____Drug 5S I R N

____Drug 6S I R N

____Drug 7S I R N

____Drug 8S I R N

____Drug 9S I R N

Organism 2(specify)

____Drug 1

____Drug 2

____Drug 3

____Drug 4

____Drug 5

____Drug 6

____Drug 7

____Drug 8

____Drug 9

Surgical Site Infection (SSI) Page 2 of 3OMB No 0920-0666

Exp Date 03-31-2011

(specify) _________________________

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 20: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Laboratory Scope1Positive culture from aspirate or drainage or tissue from affected site

If organisms are normal skin flora diphteroides bacillus propionobacter coagulase neg Staph viridans group Strep Aerococcus Micrococcus they must be a pure culture

2Positvie blood culture

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 21: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

WOUNDS AND ABSCESSResident microbial flora of the skin

bull Diphtheroids

bull Staphylococcus epidermidis

bull Other coagulase negative staphylococci

bull Propionobacterium acne

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 22: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

WOUNDS AND ABSCESSbull The commonest pyogenic bacteria

are

bull S aureus bull Str pyogenes bull Pneumococcus bull Pseudomonasbull Coliforms bacilli bull anaerobic organisms particularly Clostridium

perfringens bacteroides spp anaerobic cocci

bull In many cases there is a mixed infection with more than one bacterial spp

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 23: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Contamination vs colonization vs infection

bull 1Pathogenicity Commensal or low grade pathogen or high grade pathogen

bull 2Population light moderate dense

bull 3Immune response absent mild moderate severe

bull 4Tissue injury (necrosis cellular debris pus) absent mild moderate severe

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 24: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Contamination vs colonization vs infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 25: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

SPECIMEN COLLECTION amp TRANSPORTbull The swab is an inefficient sampling and tends to

desiccate the specimen and trap the bacteria

bull If possible pus or exudate should be submitted in

1 small screw- capped bottle 2 firmly stoppered tube or syringe or 3 sealed capillary tube

bull Delay in the transit of specimen to the laboratory must be avoided especially swabs where the exudate may dry

bull If it is decided to send swabs two swab is necessary one for microscopy one for culture

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 26: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

SPECIMEN COLLECTION amp TRANSPORT

bull If the swab is dry moisture it well with a little sterile broth or saline

bull The examination of material on swabs for mycobacterium is always unsatisfactory

bull Physicians should be instructed that when a special investigation is required they usually should state on the request form

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 27: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Laboratory examinationbull Special methods of examination should be

applied to particular specimens

bull The basic procedures usually include

1 A naked eye examination for macroscopy criteria color odor consistency hellip

2 The microscopical examination

3 Culture on aerobic and anaerobic blood agar plates on MacConkey agar and in cooked - meat broth

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 28: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

How to prepare smears

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 29: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

How to prepare smears

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 30: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Collection amp transport

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 31: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Microscopic examinationbull Much useful information may be obtained from a smear by

Gram-staining

bull We should notice bull 1- presence and relative numbers of PMNs and ESCbull 2- Properties of bacteria Morphology amount gram

staining arrangement)bull 3- Intra-cellular vs extra-cellularbull 4- Dominancy

bull Examination of a wet film for fungi or motile bacteria

bull A smear stained by the Ziehl- Neelsen method should be examined when the clinical circumstances suggest the tubercle bacillus another mycobacterium or a nocardia may be present

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 32: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

CULTIVATIONbull The specimen should be inoculated on two plates of

blood agar (5 SBA)

bull 1the one for incubation at 35 C 5-10 CO2 for 18-24h

bull 2the other for incubation anaerobically

bull It should also be plated on Mac Conkey or CNA or PEA agar for selective isolation of GP vs GN

bull Also be inoculated into a tube of cooked ndashmeat broth for the enrichment of exacting aerobes and anaerobes

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 33: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

CULTIVATION

bull Colonies should be noted and more tests for identification and antibiotic susceptibility

tests done

bull If there is no growth after 24h all plates should be re-incubated for another 24h usually up to 72

hours

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 34: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

CULTIVATION

bull And for slow-growing pathogen such as Actinomyces israeli or some species of bacteroides it should be

incubated longer for about 7 days

bull If at 24 h or 48 h there is growth on cooked-meat broth but no growth on the plates the broth should be filmed

and sub-cultured

bull If tuberculous or fungal infection is suspected the specimen should be cultured by the appropriate methods

on special media

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 35: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Interpretation and reportingbull A pure growth of a recognized pathogen obtained from a

wound or closed abscess is easily interpreted as significant and will be reported to the physician as being so

bull Mixed cultures grown from superficial lesions are the basic difficulty

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
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  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
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  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
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  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
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  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 36: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Interpretation and reportingskin commensals In superficial lesions

bull Scanty growths of skin commensals such as albus staph or diphteheroid bacilli are usually disregarded and not reported and a few colonies of Ecoli grown from a perineal

bull But clostridium perfringens is important

bull In superficial lesions such as varicose ulcers present of mixed commensal is not important

bull The result is reported morphotypically Many mixed fecal and skin bacteria present without giving identities or antibiotic sensitivities

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
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  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
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  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 37: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Interpretation and reportingskin commensals In deep aspirated wounds

bull But a pure growth of a commensal from an aspirated deep wound is not contamination and should be reported with AST performance

bull In general a numerous or predominant organism is likely to have pathogenic significance

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 38: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Interpretation and reportingsmear amp culture discrepancy

bull But the relative numbers of the colonies of the different organisms on a culture plate may not reflect the relative numbers of the organisms in the lesion for they are subject to many variations such as

1the relative speed of growth of different species 2antibiotic interactions between different species and 3the greater tendency of the more delicate pathogenes to die during transport of specimens

bull For such reason a causal pathogen may be cultured in smaller numbers than a contaminating commensal

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
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  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 39: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Wound Cultures Controversies

10487081048708 Is sampling a wound for culture relevant 10487081048708 When and how should wounds be sampled

10487081048708 How should samples be transported10487081048708 What analysis should be requested

Gram stain only Culture only

Susceptibility testingQuantitative cultures

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 40: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

WoundsCultures

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 41: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Wound CulturesFor open wounds

bull Clean the wound margins with surgical soap or70 ethyl or isopropyl alcohol

bull Aspirate from the depth of the wound using asterile syringe and needle

bull Aspirated fluid should be sent to the laboratory in an appropriate transport system

bull Alternatively a curette may be used to obtaintissue from base of the wound

bull Swabs are strongly discouraged

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 42: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Wound CulturesFor closed wounds

bull Prepare site as described for obtaining blood culture

bull Aspirate as much purulent material as possiblebull Transport in aerobicanaerobic transport

system

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
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  • Slide Number 7
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  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
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  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
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  • Slide Number 50
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  • Slide Number 53
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  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 43: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Interpretation of results Algorithms

bull Three approaches10487081048708 PMN predominance10487081048708 Q-Score10487081048708 Q-2-3-4 system

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
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  • Slide Number 9
  • Slide Number 10
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  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
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  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
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  • Slide Number 53
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  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 44: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Wound Specimens Algorithms

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
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  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 45: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Wound Culturesbull Culture for aerobic and anaerobic

bacteria if appropriately collected10487081048708 Gram stain results suggest adequate

collection orpresence of inflammation

10487081048708 Tissues or aspirates vs swabs

10487081048708 Primary plating media 5 SBA Choc agarMacConkey agar anaerobic plates and thio ifappropriately collected

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 46: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Extent of workupbull Identify anaerobes to Genus level onlybull Use Gram stain result

10487081048708 Work up organisms seen on stain only10487081048708 List others

bull Work up any potential pathogens to maximum of three list others present by morphology

bull Work up any quantity S aureus P aeruginosa beta hemolytic streptococci enterics and gram negative anaerobes

bull Perform susceptibility testing of predominant organisms only

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
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  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 47: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 48: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Use Gram stain result10487081048708 Work up organisms seen on stain only10487081048708 List others

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 49: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Work up any potential pathogens to maximum of three

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 50: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Workup of Wound Culturesbull Q-Score System10487081048708 Good quality specimen (Q3)

Up to 3 organisms can be considered as potentialpathogens and worked up (IDAST)

10487081048708 Lower quality specimen (Q2 Q1)More SECFewer organisms are worked up

10487081048708 If the Q-score is greater than or equals the PPin culture

Workup all potential pathogens10487081048708 If Q-Score is less than the PP in culture

Look at the Gram stainWorkup all PP that are seen on GSMorphologically ID othersIf all PP present on GS then only Morph ID all

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
  • Slide Number 3
  • Slide Number 4
  • Slide Number 5
  • Slide Number 6
  • Slide Number 7
  • Slide Number 8
  • Slide Number 9
  • Slide Number 10
  • Slide Number 11
  • Slide Number 12
  • Slide Number 13
  • Slide Number 14
  • Slide Number 15
  • EPIDEMIOLOGYwound classification
  • Slide Number 17
  • Slide Number 18
  • Slide Number 19
  • Slide Number 20
  • Slide Number 21
  • Slide Number 22
  • Slide Number 23
  • Slide Number 24
  • Slide Number 25
  • Slide Number 26
  • Slide Number 27
  • Slide Number 28
  • Slide Number 29
  • Slide Number 30
  • Slide Number 31
  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
  • Slide Number 45
  • Slide Number 46
  • Slide Number 47
  • Slide Number 48
  • Slide Number 49
  • Slide Number 50
  • Slide Number 51
  • Slide Number 52
  • Slide Number 53
  • Slide Number 54
  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
  • Slide Number 77
  • Slide Number 78
  • Slide Number 79
  • Slide Number 80
  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 51: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Workup of Wound Cultures

bull Q2-3-4 System10487081048708 Culture workup is based on the of PP present

2PP ndash IDAST 3PP

Look at the Gram stainWorkup two PP if they are seen on GS

If all 3 present on GS then Morph ID4PP

Morph ID only

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

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  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
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  • EPIDEMIOLOGYwound classification
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  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
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  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
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  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
Page 52: Nosocomial Pathogens · 2018. 9. 17. · Nosocomial Pathogens NNIS, Jan. 1990 -Mar. 1996 0 5000 10000 15000 20000 25000 30000 35000 40000 Urinary Tract Infection Surgical Site Infection

Wound Cultures Example

Gram stainmany neutrophils few epithelial cellsGrampositive cocci in clusters Gram positive cocci in chains

Culture growsmany S aureus many Group Astreptococci few enteric bacilli

Q score = 2 [PMN (+3) few epi (-1)]Q2-3-4 = 3 PP

10487081048708 look at gram stain

Work upS aureus Group A streptococcus Morph ID and no susceptibility on enteric bacilli

  • Slide Number 1
  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
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  • EPIDEMIOLOGYwound classification
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  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
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  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
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  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144
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  • Nosocomial PathogensNNIS Jan 1990 - Mar 1996
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  • EPIDEMIOLOGYwound classification
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  • Slide Number 32
  • Slide Number 33
  • Slide Number 34
  • Slide Number 35
  • Elective Surgical ProceduresHair Removal
  • Slide Number 37
  • Slide Number 38
  • Slide Number 39
  • Shaving Clipping and SSI
  • Slide Number 41
  • Slide Number 42
  • Slide Number 43
  • Slide Number 44
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  • Slide Number 55
  • Slide Number 56
  • Slide Number 57
  • Slide Number 58
  • Slide Number 59
  • Slide Number 60
  • Slide Number 61
  • Slide Number 62
  • SSIs and Glucose Levels CTS pts
  • Slide Number 64
  • Slide Number 65
  • Slide Number 66
  • Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)SENTRY ndash US and Canada 2000
  • Microbiology
  • Unusual pathogens of SSIs
  • Progression of Methicillin Resistant S aureus ndash United States
  • Slide Number 71
  • Slide Number 72
  • Slide Number 73
  • Slide Number 74
  • Slide Number 75
  • Slide Number 76
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  • Slide Number 81
  • Slide Number 82
  • Slide Number 83
  • Slide Number 84
  • Slide Number 85
  • Slide Number 86
  • Slide Number 87
  • Surgical site
  • Slide Number 89
  • Slide Number 90
  • Slide Number 91
  • Slide Number 92
  • Slide Number 93
  • Pathogenesis of SSI
  • Slide Number 95
  • Slide Number 96
  • Slide Number 97
  • Slide Number 98
  • Slide Number 99
  • Laboratory Scope
  • WOUNDS AND ABSCESS Resident microbial flora of the skin
  • WOUNDS AND ABSCESS
  • Slide Number 103
  • Slide Number 104
  • Slide Number 105
  • Slide Number 106
  • Slide Number 107
  • Slide Number 108
  • Slide Number 109
  • Slide Number 110
  • Contamination vs colonization vs infection
  • Contamination vs colonization vs infection
  • SPECIMEN COLLECTION amp TRANSPORT
  • SPECIMEN COLLECTION amp TRANSPORT
  • Laboratory examination
  • Slide Number 116
  • Slide Number 117
  • How to prepare smears
  • How to prepare smears
  • Collection amp transport
  • Microscopic examination
  • CULTIVATION
  • CULTIVATION
  • CULTIVATION
  • Interpretation and reporting
  • Interpretation and reporting skin commensals In superficial lesions
  • Interpretation and reporting skin commensals In deep aspirated wounds
  • Interpretation and reportingsmear amp culture discrepancy
  • Wound Cultures Controversies 1048708 Is sampling a wound for culture relevant 1048708 When and how should wounds be sampled1048708 How should samples be transported1048708 What analysis should be requested Gram stain only Culture only Susceptibility testingQuantitative cultures
  • WoundsCultures
  • Wound Cultures For open wounds
  • Wound Cultures For closed wounds
  • Interpretation of results Algorithms
  • Wound Specimens Algorithms
  • Wound Cultures
  • Extent of workup
  • Slide Number 137
  • Slide Number 138
  • Work up any potential pathogens to maximum of three
  • Slide Number 140
  • Workup of Wound Cultures
  • Workup of Wound Cultures
  • Slide Number 143
  • Slide Number 144

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