nci mdro
TRANSCRIPT
Prepared & Presented by:
GERRY A. BERNAS
Senior Lab Tech
SQH
i. Definition
ii. Factors resulting to the rise of NCI
iii. Routes of transmission
iv. Sites of infection
v. Occurrence of NCI
vi. Consequences of NCI
vii. Pathological agents
viii. Examples of MDRO.
ix. Bacterial Identification
x. Mechanism of resistance
xi. Role of clinical microbiology lab.
xii. Determining drug resistance.
xiii. Prevention NCI.
Nosocomial Infection (NCI)
Any infection causing illness that was not present
when the patient was admitted to the hospital or
received treatment in OPD.
Infection considered nosocomial if they first appear
48 hrs or more after admission or within 30 days
after discharge.
MDRO ( Multi- drug resistant organism)
Defined as organisms that are resistant to different
classes of anti-microbial agents also called as
antibiotics.
WHO notes that the rate of nosocomial infections
will continue to rise as a result of:
1. Emergence of MDRO.
2. Crowded hospital condition.
3. Increasing number of immunocompromised
patients
4. Appearance of new microorganisms.
1. Contact - Direct physical transfer of
microorganism between a host and
susceptible person.
2. Airborne/droplet. Generated by
coughing, sneezing or respiratory
procedures such as bronchoscopy or suction
- Tiny droplets nuclei ( < 5 microns) remain
suspended in the air.
Con’t..
3. Vector- transmitted through insect bites.
Mosquito bites can transmit malaria and
dengue fever.
4. Common vehicle of transmission
transmitted indirectly by material contaminated
with infectious agents
a. contaminated blood products.
b. contaminated instrument.
c. contaminated food and water.
- Urinary tract 40%
- Surgical wound 15 %
- Respiratory tract 15%
- Skin 10%
- Blood (Bacterimia) 10%
- Others 10%
1. Presence of microorganism in hospital
environment.
2. Immunocompromised patient or any
susceptible host.
3. Transmission of pathogen between staff and
patient or among patient.
1. Additional suffering of patient.
2. Prolong hospital stay.
3. Increased cost of care.
4. Increased morbidity and mortality rate-
death.
MDRO related nosocomial infection has a
mortality rate of more than 50%
1. Bacteriaa. Commensal bacteria – found in the normal
flora of healthy people as skin, nose, axilla, groin, throat. They have lesser virulence but can cause I.V infection and bacterimia.
Ex. Staph epidermidis
Strept viridans
a. Pathogenic bacteria – they have greater virulence and cause infection ( sporadic or endemic)
- They can colonise a healthy person without causing infection and can transmit to another person and will cause them infection.
- some strains develop resistance to
antibiotic and some are highly resistant
(MDRO)
2. Viruses
a. Hepatitis virus (HBV, HCV)
b. HIV
3. Fungi
a. Candida albicans
B. Aspergillus spp
C. Cryptosporidium
1. MRSA (methicillin- resistant staph aureus)
- staph aureus causes a wide variety of
infection and common cause of hospital
acquired infection like wound infection
(abcess), UTI, pneumonia, endocarditis,
osteomyelitis and food poisoning (entero-
toxin).
- MRSA is staph aureus that are resistant to
certain antibiotics called beta-lactams
includes methicillin, oxacillin, penicillin
and amoxicillin.
BIOCHEMICAL TEST STAPH AUREUS OTHER STAPH
SPP/EPIDERMIDIS
CATALASE + +
COAGULASE + _
DNASE + _
Con’t…
- This is because of their ability to produce the
enzyme beta lactamase which breakdown the
drug and render it ineffective.
- Vancomycin is considered the only effective
antibiotic against MRSA.
2. ESBL ( EXTENDED – SPECTRUM BETA-
LACTAMASE)
- ESBL is an enzyme which built up a form of
resistance of community use antibiotics the
extended spectrum cephalosporins (
cefotaxime, cefriaxone, ceftazidime and
monobactams).
- ESBL develops co-resistance with antibiotics
aminogycosides, septrin ( sulfomethoxazole-
trimthoprim), flouroquinolones, tetracycline
and chloramphenicol.
- ESBL enzyme is produced by gram negative
enterobacteriaceae, the most common are E.Coli
and klebsiella pneumoniae.
- Enterbacteriaceae are group of enteric bacteria
that found in intestinal tract of normal individual.
However, they can cause severe infection like
septicemia, UTI, wound infection and pneumonia.
- Patients who are colonized or infected with ESBL
bacteria can spread to other patients through direct
contact, poor hygiene and by contaminated
equipment or via hands of health care workers.
ESBL detection method:
Inhibitor potentiated diffusion test
This test performed by placing two sensitivity discs
on a mueller- hinton sensitivity plate inoculated
with a bacteria suspected ESBL.
One of the discs is impregnated with ESBL inhibitor
like clavulanic acid.
It is then incubated at 37oC and the minimal
inhibitory concentration is measured the next day.
Fig. 1. Phenotypic confirmation test of an ESBL producing strain showing
zone size of more than 5 mm in the disk with ceftazidime and clavulanic
acid (CAC) as compared to Ceftazidime (CA).
3. CRE: carbapenem resistant
enterobacteriaceae
- carbapenem (impenem, meropenem) are class
of antibiotics considered to be the drug of last
resort.
- CRE in general were become resistant to
almost all antibiotic and it can be very difficult
to treat.
- nosocomial infection due to CRE has a
mortality rate of more than 50%.
- like ESBL, the enterobacteriaceae, a group
of gram negative enteric bacilli develops
resistance to carbapenem example E.Coli and
Klebs pneumoniae.
- CRE are also named as superbug, patients
whose care require ventilators, urinary
catheter, IV catheter are the most high risk
of infection.
- Colistin and Tigecycline are the drugs of
choice for CRE infection.
Mechanism of resistance of CRE:
- CRE has different types of carbapenemase
enzymes.
1. Klebsiella pneumonia carbapenemase (KPC)
2. New Delhi Metallo beta-lactamase (NBL)
3. Verona Integron-Encoded metallo beta-
lactamase (VIM)
4.Imipenemase metallo beta-lactamase (IMP)
4. Acinetobacter baumannii
- is aerobic gram negative bacilli
- non lactose fermenter on Mcconkey agar.
- Multi drug resistant acineto.baumannii is a
rapidly known pathogen in health care facilities.
Its ability to survive in a long period of time on
surfaces makes it a major cause of nosocomial
infection and outbreaks.
- it can be found in
curtains, laryngeoscope, cupboard, door
handle, mops, keyboard, telephone etc.
- it has ability to colonize healthy individuals as
well as patients without causing infection.
- immunocompromised patients are of high risk of severe infection because it can be resistant to almost all drugs except Tigecycline (glycylcycline) and colistin (polymixin E).
- infection includes bacteremia, pneumonia, meningitis, UTI and wound infection.
Mechanism of resistance of A. baumannii
-Resistance is due to its impermeable membrane and it posses wide array of enzyme lactamases that hydrolyse penicillin, cephalosporins and carbapenems.
5. Other MDRO
A. Pseudomonas aeroginosa and stenotrophomonas
maltophilia.
- Aerobic, gram negative bacilli
- Non lactose fermenting colony on mcconkey agar.
- They closely related bacteria, can be found in soil,
water, sewage, hospital environment
- they exhibit resistance to most potent antibiotics
cephalosporins, carbapenem etc, and they are
opportunistic human pathogen infecting
immunocompromised patients.
B. VRE. Vancomycin resistant entercocci.
C. XDR –TB . Extensive drug resistant TB.
API SYSTEM: API 20E and API 20NE
-Standardized, miniaturized microtubes
system consist of series of biochemical test
used for identification of gram-negative
bacteria.
-Microtubes are reconstituted with
bacterial suspension and then incubated at
37’C for 18-24 hrs.
-Identification of bacteria is based on
seven digit profile of Analytical Profile Index
(API).
1. Drug inactivation by enzymatic
degradation of antibiotic (beta-
lactamase enzyme)
2. Mutation of binding site
3. Decreased permeability of bacteria cell
membrane.
4. Efflux pumps
5. Transduction of genes.
1. Disc-diffusion method (Kirby-bauertechnique)
-This is a drug sensitivity test, a semi-quantitative test where petri dish filled with sensitivity media (mueller-hinton agar) is completely inoculated and covered with pure culture of bacteria , then small disc saturated with specific antibiotic over the surface and incubated over night at 37o C. the zone of inhibition is measured and compared to the present standard to determine the antibiotic sensitivity.
Kirby-Bauer sensitivity technique in Mueller-Hinton Agar
2. E.Test
It is consist of a predefined gradient of antibiotic
concentration on a plastic strip and it is used to
determine minimum inhibitory concentrations
(MIC) of antibiotics.
The clinical laboratory has important role in
controlling hospital-acquired infection by
accurately identifying nosocomial pathogens
and detecting unexpected MDRO to prevent
outbreaks.
1. Isolation
2. Sterilization
3. Hand washing
4. Wearing personal protective equipment
- gloves
- apron
- mask
5. Proper waste disposal
WASH NOW!!!
Thank You