Streptococcaceae and Similar Organisms Flashcards
1
Q
Group A (S. pyogenes) transmission
A
respiratory secretions
2
Q
Group A Strep disease assocation
A
- pharyngitis
- scarlet fever
- otitis media
- necrotizing fasciitis
- impetigo
- cellulitis
3
Q
Group A strep sequelae
A
- rheumatic fever
- post-streptococcal glomerulonephritis
4
Q
Group A strep biochemical traits
bacitracin
PYR
A
- bacitracin susceptible
- PYR pos
5
Q
- Group A strep colony morphology
A
- pinpoint
- translucent
- large zone of beta hemolysis
6
Q
List Group A strep virulence factors
A
- M protein
- streptococcal pyrogenic exotoxin aka erythrogenic toxin
- streptokinase
- hyaluronic acid capsule
- Streptolysin O and S
- hyaluronidase
7
Q
M protein
A
inhibits phagocytosis
Ab to M protein are protective
8
Q
erythrogenic toxin
A
- causes rash seen in scarlet fever
- superantigen that interacts with macrophages and T helper cells -> TSS
9
Q
streptokinase
A
dissolves clots (fibrinolysis)
10
Q
hyaluronic acid capsule
A
inhibits phagocytosis
11
Q
streptolysins O and S
A
lyse erythrocytes, platelets, and neutrophils
12
Q
hyaluronidase
A
- hydrolyzes hyaluronic acid to aid infection spread
- strains that make hyaluronic capsule do not make hyaluronidase
13
Q
S. dysgalactiae subsp. equisimilis Lancefield Group
A
Lancefield Group C or G antigens
14
Q
S. dysgalactiae subsp. equisimilis disease association
A
- similar to S. pyogenes
- pharyngitis, necrotizing fasciitis, STSS, endocarditis, glomerulonephritis. acute rheumatic fever
15
Q
Group B strep (S. agalactiae) normal environment
A
normal flora of GIT