Term
Group A
-metabolism
-virulence
-diseases caused by direct invasion/toxin
-diseases mediated by Ab
-diagnostics |
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Definition
Strep pyogenes
Catalase-neg
Microaerophilic
Beta-hemolytic
-Streptolysin O: oxygen labile, antigenic
-Streptolysin S: oxygen stable
M-protein: adherence, anti-phagocytic, antigenic
Lipoteichoic acid: adherence
Streptokinase
Hyaluronidase
DNAase
Anti-C5a peptidase
DIRECT INVASION/TOXIN:
Pharyngitis
Folliculitis, cellulitis, impetigo, necrotizing fasciitis
Erythrogenic (pyogenic) toxin - scarlet fever
TSS toxin
AB MEDIATED
Rheumatic fever: fever, myocarditis, arthritis, chorea, erythema marginatum, subQ nodules, 10-20 post may get heart valve damage
Acute post-streptococcal glomerulonephritis: tea urine
Gram+ cocci in chains
Growth inhibited by bacitracin (the only beta-hemolytic strep which is)
Pharyngitis: throat swab rapid antigen detection test |
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Term
Group B
-metabolism
-pathology
-diagnostics |
|
Definition
Catalase-neg
Facultative anaerobe
Beta-hemolytic
Neonatal meningitis, pneumonia, sepsis
Sepsis in pregnant women
Elderly, pts with diabetes or neurological disease
Gram stain of CSF or urine
Culture of CSF, urine or blood
*CAMP test* |
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Term
Group D
-2 sub-types
-metabolism
-virulence
-pathology
-diagnostics
-miscellaneous |
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Definition
Enterococci: Strep faecalis, S. faecium
Non-enterococci: S. bovis, S. equinus
Catalase-neg
Facultative anaerobe
Alpha-, beta-, or gamma-hemolytic
Extracellular dextran helps them bind to heart valves
Subacute bacterial endocarditis
Biliary tract infections
UTI (esp enterococci)
Gram stain
Enterococci cultured in: 40% bile, 6.5% NaCl
Non-enterococci can only grow in bile
S. bovis associated with colonic malignancies |
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Term
Strep viridans
-metabolism
-virulence
-pathology
-diagnostics
-miscellaneous |
|
Definition
Cat-neg
Facultative anaerobe
Alpha-hemolytic
Extracellular dextrans helps them bind to heart valves
Subacute bacterial endocarditis
Dental caries - S. mutans
Brain or liver abscesses: S. intermedius
Gram stain
Resistant to optochin
Part of the normal oral flora |
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Term
Strep pneumoniae
-metabolism
-virulence
-toxins
-pathology
-diagnostics
-miscellaneous |
|
Definition
Cat-neg
Facultative anaerobe
Alpha-hemolytic
Polysaccharide Capsule - phagocytosis defense
Pneumolysin: binds to cholesterol in host cell membranes
Pneumonia
Meningitis
Sepsis
Otitis media (children)
Gram-positive diplococci
Culture does NOT grow in presence of: optochin, bile
Positive Quellung test: swelling when tested against antiserum containing anti-capsular Ab
Quellung rxn is used to detect encapsulated bact (S. pneumo, H. influenzae)
**rusty sputum** |
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