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Flashcards in L37 Deck (34):
1

What is the universal property of steptococcus?

GP cocci - pairs or cocci
Catalase NEGATIVE

2

Which strep is group A, beta hemolytic?

S. pyogenes

3

Which strep is group B, beta hemolytic?

S. agalactiae

4

What 4 infections are you thinking about with strep pyogenes?

Pus forming:
1. Pharyngitis = strep throat!
2. Skin infections
Non-pus:
3. Rheumatic fever
4. Glomerulonephritis

5

What virulence factor is particularly important for strep pyogenes? (baker's hat)

M protein
- Inhibits alternative complement
- But... elicits opsonic Abs
- Adhesion to keratinocytes (skin infections)
**Many different types - you need to have immunity to that specific epitope

6

How does M protein contribute to rheumatic heart disease?

Abs made against M protein are auto-reactive to heart muscle

7

Describe other virulence factors notable for s.pyogenes.

1. GP capsule = anti-phagocytic
2. Surface adhesion molecules
3. Toxins

8

Which hemolysin toxin released by s.pyogenes is tested for recent infection?

Streptolysin O titer
Abs vs this indicate recent infection
Important for RF & glomerularnephritis diagnosis

9

What are the exotoxins secreted by s.pyogenes? Why do peoples symptoms to these toxins vary?

SpeA/B/C = pyrogenic exotoxins
Superantigens
Responsible for Scarlet Fever & TSS
**HLA dep response - will intrinsically vary from person to person**

10

How is staph pyogenes transmitted?

Oral secretions
Skin lesion contact

11

Which pus forming skin infections can s.pyogenes cause?

Impetigo
Erysipelas
Nec fasc
TSS

12

How do you test for s.pyogenes in strep throat?

Rapid antigen
- V. specific - if positive, you've got it
Also take swab culture in case false negative

13

Why do you treat strep throat?

Prevent Scarlet Fever!

14

Drugs for pharyngitis

Penicillin
Allergic:
- Macrolides
- Clindamycin

15

What are the presenting symptoms of scarlet fever?

Rash started on trunk
Strawberry tongue
Broken capillaries --> skin folds
Peeking skin (desquamation)

16

What are some tell tale symptoms of impetigo?

Honey crusted skin lesions
- Look like this b/c of pus coming out of the wounds

17

Drugs for impetigo

TOPICAL
Bacitracin
Mupirocin
MRSA/more extensive disease
Amoxicillin/clavulanic acid
Cephalexin

18

What is erysipelas?

**MENTAL TIE TO S.PYOGENES**
Red, swollen rash w/ sharp edges
Form of cellulitis
+ "Fever and I don't feel good"

19

What could result for s.pyogenes weird tie to lymphatics?

Cellulitis w/ lymphagitis
= Streaking to draining lymph node

20

What are the clinical symptoms for nec fasc?

Pain out of proportion
Hemorrhagic bullae
May have progressed to septic shock

21

Explain how s.pyogenes can cause toxic shock syndrome?

Had s.pyogenes skin infection
SpeC toxin = superantigen
+ you have the right HLA to react
Cytokine storm

22

Which s.pyogenes infection can progress to cause RF?

Strep throat ONLY!

23

What are you concerned about if you don't clear the s.pyogenes infection causing RF?

Repeated RF --> rheumatic heart disease
Irreversible damage

24

How long does glomerulonephritis present after the primary s.pyogenes infection? What types of s.pyogenes infections can cause this complication?

2 weeks post pharyngitis OR skin infection

25

Where does s.agalactiae colonize the body?

GI
Female GU

26

What patient population are you likely to see with s.agalactiae infections?

Neonates!!!

27

How do you treat mom with colonization for s.agalactiae?

Penicillin before birth
Vanco or clinda if allergic

28

What type of hemolysis does s.anginosis display? Clinical presentation?

= type of viridans strep
Can do B, G, or A hemolysis
Causes abscesses: liver, brain, teeth

29

What is viridans strep?

Can be A or G hemolytic
Subdivided into MANY groups
Colonizes mucous surfaces but NOT skin

30

Which viridans strep cause bactermia & endocarditis in patients with colonic neoplasia?

S.bovis group
- S.gallolyticus

31

Drugs for viridans strep

1. Penicillin
Allergic:
2. Vanco

32

Does strep viridans cause pneumonia?

NO
It is on the mucosal surfaces of the mouth - you contaminated the scope as you went down to stake culture sample
Don't chose your antibiotic based on its presence in the pneumo culture

33

Why might someone present with strep viridans bactermia and endocarditis?

Post dental work if got into blood

34

Which clinical diseases make you think of strep agalactiae?

Neonates:
- Meningitis
- Pneumonia
- Sepsis
Adults w/ underlying disease