Mico I Flashcards
What are the morphological features of Staph aureus?
Gram positive cocci in grape like clusters
What staph aureus aerobic, anaerobic, or a facultative anaerobe?
facultative anaerobe
What are the reservoirs of staph aureus?
Skin and nose
How is staph aureus resistant to PCN?
Produces beta-lactamase and altered binding site for PCN (MRSA)
What is the role of protein A in staph aureus?
Binds Fc IgG to inhibit complement activation and phagocytosis
What is the function of catalase?
degrades H2O2
What does the TSST toxin of staph aureus bind to?
MHC II
What is the role of coagulase that staph aureus produces?
Forms fibrin clots around self in an abscess
What does it mean when a bacteria is has a beta hemolysis pattern?
Forms a clear area of hemolysis on blood agar
What are the four major beta hemolytic bacteria?
- Staph aureus
- Strep pyogenes
- Strep agalactiae
- Listeria monocytogenes
What is the toxin that staph produces to cause GI issues?
Enterotoxin
What is virulence factor the staph produces to cause SSSS?
Exfoliative toxin
How do you differentiate staph epidermidis from other coagulase negative staph?
Novobiocin sensitive
How do you differentiate staph saprophyticus from other coagulase negative staph?
Novobiocin resistant
What is the treatment for staph aureus infections? (MRSA and not)
Nafcillin (for all but MRSA), and vanco for MRS
What part of the heart is affected with staph aureus?
Right side of the heart (d/t immune system presence in the pulmonary vasculature)
What are the four common diseases that staph pneumoniae causes?
Meningitis
Otitis
Pneumonia
Sinusitis
How do you differentiate staph pneumoniae from other alpha hemolytic bacteria?
Optochin sensitive
What are the two alpha hemolytic bacteria?
Strep viridans
Strep pneumoniae
What are the two beta hemolytic strep species?
Strep agalactiae
Strep pyogenes
What are the four major penicillinase resistant first generation antibiotics?
- Nafcillin
- Oxacillin
- Methicillin
- Dicloxacillin
What is the mechanism of action of penicillin?
Destroy the peptidoglycan linkages in the beta lactam ring