gram positive (purple/blue) coccirods (bacilli) clostridium (anaerobe) listeria bacillus...

Gram Positive (purple/blue)

Cocci Rods (bacilli)CLOSTRIDIUM (anaerobe) LISTERIABACILLUSCORYNEBACTERIUM

Catalse (+)STAPH

Catalse (-)STREP

Coagulase (+)S. AUREUS

Coagulase (-)

Novobiocin (+)S. EPIDERMIDIS

Novobiocin (-)S. PNEUMONIAE

Hemolysis

α

β

γ

CapsuleS. PNEUMONIA

No CapsuleVIRIDANS STREP

Group AS. PYOGENESGroup BS. AGALACTAIE

ENTEROCOCCUSPEPTOSTREPTOCOCCUS

Gram Negative (pink)

Cocci Rods

“Coccoid” RodsH. FLUPASTURELLABRUCELLABORDETELLA PERTUSSISMaltose Fermenter

NEISSERIA MENINGITIDISNon FermenterNEISSERIA GONORRHOEAE

Fast lactose FermenterKLEBSIELLAE. COLIENTEROBACTER

Slow FermenterCITROBACTERSERRATIA

Lactose Nonfermenter

Oxidase NegativeSHIGELLASALMONELLAPROTEUS

Oxidase PositivePSEUDOMONAS

Gram positive Gram negative

2 envelope layers: 1) cytoplasmic membrane 2) thick peptidoglycan layer

3 envelope layers: 1) cytoplasmic membrane 2 )thin peptidoglycan layer

3) phospholipid/LPS Low lipid content High lipid contentNo endotoxin Endotoxin No periplasmic space Periplasmic space

Teichoic Acid O Specific Side chain

Metabolic Characteristics

• Obligate aerobes

• Facultative anaerobes

• Microaerophilic bacteria

• Obligate Anaerobes

•Love oxygen •Need it to grow•Have all 3 enzymes

•Like oxygen /doesn’t require it

•Can use anaerobic fermentation

•Catalase and Superoxide Dismutase

•Like small amounts of oxygen•Aerotolerent anaerobes•Superoxide Dismutase

•Don’t like oxygen•No enzymes to counter act

Gram Positive Pathogens• Cocci

– Staphylococci– Streptococci

• Rods (bacilli)– Spore formers

• Bacillus • Clostridium

– Nonspore formers• Nonfilamentous

– Corynebacterium– Listeria– [Mycobacterium-kind of]

• Filamentous– Actinomyces– Nocardia

Gram Positive Pathogens

Staphylococcus

StreptococcusCocci-catalase test

Streptococci-negative

Staphylococci-positive

Genus: Staphylococci• Gram Positive Cocci in groups and clusters• Catalase positive• Coagulase Test for differentiation

– S. Aureus-positive– S. Epidermidis-negative– S. Saprophyticus-negative

Virulence factors

•Surface protein A binds to Fc portion of IgG (prevents opsonization)

•Enterotoxin and TSST-1 toxins

Staphylococcus AureusDirect infection

Impetigo

MRSA

Staphylococcus Aureus diseases due to toxins

Scalded Skin Syndrome

Enterotoxin

Very stable

TSST-1

Genus: Staphylococcus

Staph Epidermidis

Genus: Streptococcus

Catalase Negative Gram Positive Cocci in pairs and chains

Genus: Streptococcus

• S. pyogenes• S. agalactiae• S. pneumoniae • Enterococcus

Genus: Streptococcus

• Lancefield Antigens– Lancefield antigens denote cell wall carbohydrates– The presence of Lancefield antigens defines the

pyogenic streptococci– Groups A through T

• A,B, C and D are most important

– Some Streptococcus are not assigned (they do not possess) Lancefield antigens

Genus: Streptococcus

• Hemolysis on BAP• The hemolysis is defined as alpha, beta and gamma

No Complete Partial

Genus: Streptococcus• Strep Pyogenes

– Group A Beta Strep– Strep throat, scarlet fever, rheumatic fever, acute

glomerulonephritis, impetigo• Strep Agalactactiae

– Group B Beta Strep– Perinatal sepsis, meningitis and/or pneumonia

• Strep Pneumoniae– Pneumococcus– Optichin Sensitive– Otitis media, pneumonia, meningitis

• Enterococcus – Group D– UTI

Genus: Streptococcus

• Group A Beta Strep– S. pyogenes

• Strep Throat• Scarlet Fever• Rheumatic Fever• Post Streptococcal Glomerulonephritis• Impetigo

Strawberry tongue

Pharyngitis

Lancefield Antigen Hemolysis on BAP

Chromatographic Immunoassay

Genus: Streptococcus

• Strep Agalactactiae– Group B Beta Strep– Perinatal sepsis, meningitis and/or

pneumonia• Early Sepsis within one week of birth• Late Sepsis from 7days to 3 months of

birth

Genus: Streptococcus• Alpha hemolysis• Optichin Sensitive• Gram positive Lancet Shaped Diplococci • Strep Pneumoniae

– Pneumococcus (nickname)– Otitis media, pneumonia, meningitis

Right lower lobe pneumoniaencapsulated

Significant sequalae

Genus: Streptococcus

• Enterococcus – Group D– Virulence Factors

• Abx resistant due to PBP• Acquired Resistance• Enzymes• Adherence factors• Biofilm formation

– UTI, catheter related infections

Gram Positive Spore Forming Rods

• Bacillus (Fac. Anaerobe)• Clostridium (Strict Anaerobe)

Genus: Bacillus

• Fac. Anaerobe• G + Spore Forming Rod • Bacillus

– B. Anthracis• Cutaneous• Respiratory• Intestinal

RespiratoryB. Anthracis

BAP

Genus: Clostridium

• Anaerobic G + Rod• Spore formers• Clostridium

– C. Perfringens– C Tetni– C. Botulinum– C. Difficile

Target hemolysis on BAP ~ two zones due to production of 2 toxins

Myonecrosis/ gas gangrene

Genus: Clostridium• Anaerobic G + Rod• Spore formers• Clostridium

– C. Perfringens– C Tetni– C. Botulinum– C. Difficile

Terminal Spore

Tennis Racket

Neurotoxin binds to presynaptic terminals in prevents transmission of inhibitory neurotransmitters

DTP and DTaP

Genus: Clostridium

• Anaerobic G + Rod• Spore formers• Clostridium

– C. Perfringens– C Tetni– C. Botulinum– C. Difficile

Infantile Botulism caused by spore ingestion with endogenous toxin production

Spores

Toxin ingestion (usual)

Genus: Clostridium• Anaerobic G + Rod• Spore formers• Clostridium

– C. Perfringens– C Tetni– C. Botulinum– C. Difficile

Plain film of abdomen showing bowel wall thickening, loss of haustral markings (thin arrow) and dilation of the ascending and transverse colon (thick arrow)

Endoscopic view of Psuedomembranous colitis

Gram Positive Nonspore Forming Rods

• Nonfilamentous– Corynebacterium– Listeria– [Mycobacterium-kind of]

Genus: Corynebacterium• Gram Positive Nonspore Forming Rods• Immobile• Nonencapsulated• Nonfilamentous• Corynebacterium

– C. Diphtheriae

Pallisades/ Chinese Letter Arrangements

Barred appearance (metachromatic granules)

Pseudomembrane of throat and/or nasal cavity

DTP and DTaP

Genus: Listeria

• Gram Positive Nonspore Forming Coccobacilus• Tumbling motility at 25 degrees Celsius• Nonfilamentous

– Listeria• L. Monocytogenes

Beta hemolysis

Raw milk, soft cheeses, ice cream, raw vegetables, raw or cooked poultry, raw meat, raw or smoked fish

Transplacental and birth canal transmission

Genus: Mycobacterium• Gram Positive Nonfilamentous Nonspore Forming Rods• Strict aerobe• Very slow growing• Weakly gram positive• Acid Fast-waxy cell wall-mycolic acid

– [Mycobacterium -kind of]• M. Tuberculosis• M.Leprae

Divides every 15 to 20 hours

Acid fast gram positive bacteria

PPD

Genus: Mycobacterium• Gram Positive Nonfilamentous Nonspore Forming Rods• Waxy coating->acid fast• Aerobic/ nonmotile• Can not grow in artificial culture• [Mycobacterium -kind of]

– M. Tuberculosis– M.Leprae

• Leprosy• Hanson’s Disease

Nine banded Armadillo

Incubation is 2-20 years

• Gram Positive Filamentous Nonspore Forming Rods

• Aerobic to Fac. Anaerobe• Opportunistic• Actinomyces

– A. Israelii• Nocardia

Genus: Actinomyces

• Gram Positive Filamentous Nonspore Forming Rods

• Aerobic to Fac. Anaerobe• Non acid fast• Opportunisitic• Actinomyces

– A. Israelii Lumpy Jaw

Actinomycoses infections are polymicrobial

Genus: Nocardia• Gram Positive Filamentous • Branching• Weakly acid fast• Strict aerobe• Catalase positive• Nonspore Forming Rods

– Nocardia

Primary source is soil

Colonies smell like wet dirt

Low virulence opportunistic infection

Now on to Gram Negatives

Gram Negative Cocci

• Neisseria– N. Meningitidis– N. Gonnorhea

• Moraxella– Branhemella Cattorhalis

• Gram Negative Cocci • Kidney bean shape• Ferments maltose and glucose like

meningitis• Oxidase and catalase positive• Endotoxin production• Neisseria

– N. Meningitidis• Meningiococcus (nickname)• Meningitis, septic shock

– N. Gonnorhea

Nonblanching petechial rash

Kidney bean shape

Not B

Direct or from cultured specimen

• Gram Negative Cocci• Kidney bean shaped • Neisseria

– N. Gonorrhea• Gonorrhea• Ophthalmia Neonatorum

Culture is the gold standard

Nucleic Acid Amplification TestsOphthalmia Neonatorum

$$$

• Gram Negative Cocci • Aerobic• Moraxella

– Branhemella Catorrhalis• Otitis media, sinusitis

sinusitis

Otitis media

Gram Negative Spirochetes

• Treponema– T. Pallidum

• Borrelia– B. Burgdorfi– B. Recurrentis

• Leptospira

Gram Negative Spirochetes• Too small for gram stain• Can not be cultured from clinical specimen• Dark field microscopy of clinical sample• Treponema

– T. Pallidum• Syphillus-acquired and congenital

– Nontreponemal tests– Treponemal tests

Electron Micrograph

Secondary stage

Gram Negative Spirochetes

• Microaerophilic• Geimsa or Wright stain• Borrelia

– B. Burgdorfi

Erythema migrans

western black-legged tick (Ixodes)

Gram Negative Spirochete• Aerobic• Motile• G –cell envelope• Animal reservoirs• Flexible spirochete• Not seen on gram stain• Dark field microscopy• Leptospira

– L. Interrigans

Petichial rash

Fine spirals with hooked ends

Water transmission

Many Many Gram Negative Bacilli• Respiratory

– Heamophilus – Bordetella– Legionella– Gardnerella

• Zoonotics– Yersinia– Franicisella– Brucella– Pasteurella– Bartonella

• Enterics – Many many

Respiratory Gram Negative Bacilli

• small pleomorphic, gram-negative coccobacillus. • Nonmotile• non–spore-forming• fastidious• facultative anaerobe• Heamophilus

– H. Influenzae– H. Ducryi

Respiratory Gram Negative Bacilli

• Small pleomorphic, gram-negative coccobacillus. • Nonmotile• non–spore-forming• Fastidious-X &V factor• facultative anaerobe• Heamophilus

– H. Influenzae• HIb• Epiglottitis, otitis media, meningitis, pneumonia

– H. Ducryi

Otitis media

Satelliting around Staph.

Epiglottitis

Insp. Stridor

conjugated

Respiratory Gram Negative Bacilli

• small pleomorphic, gram-negative coccobacillus.

• Nonmotile• non–spore-forming• Fastidious-X &V factor

– Dies quickly outside of body

• facultative anaerobe Heamophilus – H. Ducryi

• “soft chancre”• Culture is difficult• chancroid

Painful genital ulcer

Respiratory Gram Negative Bacilli

• Small aerobic G- Coccobacilllus• Singly and in pairs• Nicotinamide required for (slow)

growth• Bordetella

– B. Pertussis– Whooping cough

Bordet-Gengou medium

ELISA or PCR assays

DTP & DTaP Paroxysmal cough with an inspiratory whoop

Respiratory Gram Negative Bacilli

• Nicotinamide required for (slow) growth• Bordetella

– B. Pertussis– Whooping cough

Virulence factors•Pili and surface protein for adhesion•Pertussis toxin•Enzyme that disrupts immune response•Peptidoglycan injury to ciliated trachea cells

Bordet-Gengou medium

ELISA or PCR assays

DTP & DTaP

Respiratory Gram Negative Bacilli

• Poorly staining• Facultative Intracellular parasite• Compromised host• Aerobic• Legionella

– L. Pneumophila• Legionnaires' disease

– Pneumonia

Urinary antigenSputum culture

Paired serum sample

NONRespiratory Gram Negative Bacilli

• Presumptive Identification– Clue Cells– KOH

• Does not require X & V factors• Gardnerella

– G. Vaginalis• Bacterial Vaginosis (BV), preterm labor

cervicitis

Whiff TestClue cells

Zoonotic Gram Negative Bacilli• Yersinia

• Y. Pestis– Franicisella

• F. Tulerensis– Brucella

• B. Suis• B. Meltensis• B. Abortus• B. Canis

– Pasteurella• P. Multicida

– Bartonella• B. Henselae• B. Quintana

Bubonic Plague

Zoonotic Gram Negative Bacilli• Nonmotile• G- rod• Yersinia

• Y. Pestis

Pneumonic Plague

bubo

•G- bacillus•Aerobic•Low infecting dose•Vector->tick or deer fly•Special media•Immunoflourescence•Serum Serology (>1:40)•Franicisella

• F. Tularensis• Pneumonia• Glandular

Zoonotic Gram Negative Bacilli

ulceroglandular

pneumonia

Zoonotic Gram Negative Bacilli

• Nonmotile• Non-acid fast• Nonsporeforming• Small G- coccobacillus• Catalase, oxidase and urease positive• Brucella

– Brucellosis

Blood culture

Recurrent flu-like symptoms with granulomas

Zoonotic Gram Negative Bacilli

• Small G- coccobacillus• Nonspore forming• Oxidase positive• Ferments CHO• Nonmotile• PCN susceptible• Bacteriophage encoded toxin• Pasteurella

– P. Multocida• Cellulitis associated with

animal bites

Well demarcated cellulitis

Grows on BAP

Bipolar staining

Zoonotic Gram Negative Bacilli

• fastidious • pleomorphic • aerobic • gram-negative bacillus • Bartonella

– B. Henselae• Cat Scratch Fever

– B. Quintana• Trench fever• Urban Trench Fever

Cat scratch fever

Pediculus humanus

Paired sera

Family: Enterobacteriacea• Escherichia Coli• Shigella• Salmonella• Yersinia• Klebsiella• Proteus• Enterobacter • Serratia

•Enterics live in the gut-> are members of the family of Enterobacteriacea•O antigen is lipopolysaccaride•K antigen is polysaccharide capsule•H-flagellar antigen

Enterics• Facultative Anaerobe• Large G- Rods• Nonsporeformers• Normal Flora• Escherichia Coli

– E. Coli (nickname)– E. Coli 0157:H7 or

0157– UTI, Sepsis, Enteric

E.Coli, Respiratory illness, multiple opportunistic infections

UTI/ Pyelonephritis

Motile strains with peritrichous flagella

Enterics• Facultative

Anaerobe• Large G- Rods• Nonsporeformers • Relatively inert

• Shigella– S. Sonnei– S. Flexneri– S. Dysenteriae

• Shigillosis

The O antigens (LPS) define the four species of Shigella

Enterics• G- Rod• Nonsporulating,• Facultative anaerobe• Ferment glucose• Reduce nitrate• Peritrichous flagella when

motile• Produce gas upon sugar

fermentation Salmonella– S. Typhi

• Typhoid Fever– S. Enteritidis

• Gastroenteritis

Carrier states

Eggs & Enteritidis

Enterics• Nonmotile• G - rods • Prominent

polysaccharide capsule

• Multi Drug Resistant• Recently important

in nosocomial infections

• Normal flora• Klebsiella

– K. Pneumoniae• Pneumonia in

debilitated, UTI, etc etc.

Encapsulated/ multi drug resistant

Enterics• Gram Negative Rod• Normal Flora• Hydrolyzes Urea (struvite

stone formation)• Proteus

– P. Mirabilis• Opportunistic infections

including UTI

Highly motile

Enterics• G-Rod• Multi drug

resistance• Enterobacter

– E. Aerogenes– E. Cloacae

• UTI,Endocarditis, opportunistic infection

Enterics• G-rods• Opportunistic

infection Serratia– S. Marcescens

Other Gram Negative Rods• Vibrio• Helicobacter• Pseudomonas• Bacteroides

Other Gram Negative Rods• Vibrio

– V. Cholerae

Other Gram Negative Rods• Helicobacter

– H. Pylori

Other Gram Negative Rods• Helicobacter

– Campylobacter Jejuni

Other Gram Negative Rods

• Pseudomonas– Ps. Aeruginosa

Other Gram Negative Rods

• Bacteroides – B. Fragilis

• Chlamydia• Rickettsia • Coxiella• Ehrlichia

Weird Bugs

• Chlamydia – C. Trachomatis

Weird Bugs

• Obligate intercellular gram negative coccobacilli

• Vector– Dermacentor variabilis (dog

tick) East US– Dermacentor andersoni

Rocky Mountain region and Canada

• Rickettsia– R. Ricketseii

Weird Bugs

Peticheal rash

• Obligate intercellular gram negative coccobacilli

• Coxiella Brunetti

Weird Bugs

• Ehrlichia– E. chaffeensis– E. ewingii

Weird Bugs

Amblyomma americanum

Nymph left ; adult right

Ehrlichea in white tail deer fawn

Distribution of Amblyomma americanum

[Lone Star Tick]

Genus: Mycoplasma

• Pleomorphic• No cell wall• Mycoplasma

– M. Pneumoniae• Atypical pneumonia

The Inevitable Exceptions

• Mycobacteria– Weakly gram positive – Better seen with acid fast stain

• Spirochetes– Too small for light microscopy– Need Dark field microscopy

• Mycoplasma– No cell wall– Neither G+ or G-