Flashcards in L37 Deck (34):
What is the universal property of steptococcus?
GP cocci - pairs or cocci
Which strep is group A, beta hemolytic?
Which strep is group B, beta hemolytic?
What 4 infections are you thinking about with strep pyogenes?
1. Pharyngitis = strep throat!
2. Skin infections
3. Rheumatic fever
What virulence factor is particularly important for strep pyogenes? (baker's hat)
- Inhibits alternative complement
- But... elicits opsonic Abs
- Adhesion to keratinocytes (skin infections)
**Many different types - you need to have immunity to that specific epitope
How does M protein contribute to rheumatic heart disease?
Abs made against M protein are auto-reactive to heart muscle
Describe other virulence factors notable for s.pyogenes.
1. GP capsule = anti-phagocytic
2. Surface adhesion molecules
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
What are the exotoxins secreted by s.pyogenes? Why do peoples symptoms to these toxins vary?
SpeA/B/C = pyrogenic exotoxins
Responsible for Scarlet Fever & TSS
**HLA dep response - will intrinsically vary from person to person**
How is staph pyogenes transmitted?
Skin lesion contact
Which pus forming skin infections can s.pyogenes cause?
How do you test for s.pyogenes in strep throat?
- V. specific - if positive, you've got it
Also take swab culture in case false negative
Why do you treat strep throat?
Prevent Scarlet Fever!
Drugs for pharyngitis
What are the presenting symptoms of scarlet fever?
Rash started on trunk
Broken capillaries --> skin folds
Peeking skin (desquamation)
What are some tell tale symptoms of impetigo?
Honey crusted skin lesions
- Look like this b/c of pus coming out of the wounds
Drugs for impetigo
MRSA/more extensive disease
What is erysipelas?
**MENTAL TIE TO S.PYOGENES**
Red, swollen rash w/ sharp edges
Form of cellulitis
+ "Fever and I don't feel good"
What could result for s.pyogenes weird tie to lymphatics?
Cellulitis w/ lymphagitis
= Streaking to draining lymph node
What are the clinical symptoms for nec fasc?
Pain out of proportion
May have progressed to septic shock
Explain how s.pyogenes can cause toxic shock syndrome?
Had s.pyogenes skin infection
SpeC toxin = superantigen
+ you have the right HLA to react
Which s.pyogenes infection can progress to cause RF?
Strep throat ONLY!
What are you concerned about if you don't clear the s.pyogenes infection causing RF?
Repeated RF --> rheumatic heart disease
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
Where does s.agalactiae colonize the body?
What patient population are you likely to see with s.agalactiae infections?
How do you treat mom with colonization for s.agalactiae?
Penicillin before birth
Vanco or clinda if allergic
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
What is viridans strep?
Can be A or G hemolytic
Subdivided into MANY groups
Colonizes mucous surfaces but NOT skin
Which viridans strep cause bactermia & endocarditis in patients with colonic neoplasia?
Drugs for viridans strep
Does strep viridans cause pneumonia?
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
Why might someone present with strep viridans bactermia and endocarditis?
Post dental work if got into blood