Strep Pyogenes Flashcards Preview

Block 5 > Strep Pyogenes > Flashcards

Flashcards in Strep Pyogenes Deck (30):
1

strep pyogenes identifiers

gram +
cocci in chains
beta hemolysis
catalase -
bacitracin sensitive

2

non suppurative infections caused by GAS

acute rheumatic fever
acute post-strep glomerulonephritis

3

toxin mediated infections caused by GAS

scarlet fever
TSS

4

hyaluronic acid capsule

surface protein
camouflages cells
antiphagocytic propertines

5

peptidoglycan

surface protein
stablilizes structure
endotoxin

6

streptolysin S

surface protein
pokes holes in RBC membrane (beta hemolysis)

7

streptokinase

surface protein
activates plasmin to degrade clots

8

M protein

surface protein
binds to keratinocytes
antiphagocytic- blocks complement system, blocks phagocytosis/opsonization
binds fibrinogen

9

lipoteichoic acid

surface protein
sticks to mucous membranes

10

adhesions

surface protein
Fn binding proteins bind fibronectin

11

M like proteins

surface protein
antiphagocytic
bind plasma inhibitors and IgG

12

C5a peptidase

surface protein
cleaves C5a complement and prevents neutrophil recruitment

13

streptolysin O

secreted
toxin detected by ASO antibody titer

14

hyaluronidase

secreted
hydrolyzes HA to get it deeper into tissue

15

pyogenic exotinx

secreted- cause scarlet fever and skin rash

16

NADase

secreted
inhibits internalization and killing

17

DNAase

secreted
degrades free DNA in pus

18

superantigens

secreted
nonspecific activation of T cells causing a huge inflammatory response

19

main disease caused by strep pyogenes

pharyngitis (viral is most common)
ARF

20

epidemiology of pharyngitis

5-15yo
peaks in late winter
person to person spread
asymptomatic carriers

21

diagnosis of pharyngitis

throat culture to determine strep or viral
plate culture- beta hemolysis

22

treatment of pharyngitis

penicillin
macrolides

23

jones criteria for ARF

migratory arthritis
carditis
subcutaneous nodules
syndeham's chorea
erythema marginatum

24

signs of scarlett fever

scarlitinal rash- red on body
strawberry tongue

25

basis of molecular mimicry

antigens "mimic" host proteins by sharing antigens

26

what is acute glomerulonephritis

inflammatory disorder of renal glomeruli that happens after a skin strep infection--immune complexes of IgG/C3 accumulate on the basement membrane and damage it

27

PANDAS

autoimmune neuropsychiatric disorder in kids associated with strep
chorea, OCD
due to cross reactive antibodies for brain

28

strep pyoderma

impetigo
superficial skin infection in kids 2-5s
spread due to poor hygiene
vesicles --> pustules --> crusty amber lesions

29

strep cellulitis

spreading inflammation of skin and subcutaneous tissue
due to burns, wounds, or surgical infections

30

necrotizing fascitis

highly invasive fascia infection
high mortality
treat by debridement, fasciotomy, or amputation