High efficiency bacterial infecctions of the skin II Flashcards
GAS M-protein serves what function?
Is in the peptidoglycan cell wal allowing serotyping and aiding in virulence by inhibiting complement activation and macrophages.
How does Streptolysin O and Steptolysin S function and what are they found on?
GAS express these and they are pore forming similar to Staph alpha toxin.
Using Streptolysin O to get into the cell.
What are Strep super antigens?
SPE’s pyrogenic exotoxins causing cytokine storms by activating T cells!.
Impetigo is likely caused by ….
Where as bullous impetigo is caused by…?
Honeycrusted impitigo typically caused by GAS
Bullous impetigo is caused by Staph A.
What is the most common cause of cellulitis?
GAS infection.
What causes Scarlet fever?
SPE pyrogenix exotoxins from GAS starting as a rash on upper body that spreads to extemities and strawberry tongue.
What type of reaction is glomerulonephritis?
Type 3 hypersensitivity due to cross reactive antibodies seen 3-6 weeks after a GAS skin infection.
What are two indicators of glomerulonephritis?
Recent streptococcal infection and reduced serum complement concentration.
How does streptococcal toxic shock syndrome difer from Staphyloccocal toxic shock syndrome?
Streptococcal toxic shock syndrome will typically show with bacteremia and maybe even necrotizing fascitis
Pts with staph toxic shock will not display necrotizing fascitis.
What does the ASO test look for?
This is an anti-streptolysin O test looking for antibodies to streptolysin O which is tied to Strep pyogenes.
Positive in glomerular nephritis patients.
What would you treat Strep pyogenes with?
Penicillin or macrolides.
If have strep must treat with oxacillin or vancomycin
How does Exotoxin A work in pseudomonas?
Inactivates EF-2 via ADP ribosylation synthesis blocking protein synthesis.
How does pseudomonas get into other cells?
Type III secretion system.
Also uses phospholipase C (hemolysin) collagenase, lipase, elastase, pyocanin, and pyoverdin.
How might P. aeruginosa present in an osteochondritis infection?
Infection of the bone following a deep puncture wound after possibly stepping on a nail.
What are some factors that can increase susceptibility to pseudomanas infections?
Burns
Diabetes
Wet conditions
Neutropenia.
