Small Group 1: Gram Positive Cocci Flashcards
Coagglutination specific for what?
Ab to Staph aureus
Bacitracin inhibits what?
GAS
PYR test is positive for which 2 organisms?
What is substrate?
What is positive sign?
Group A and D strep (Enterococci)
Substrate is L-pyrroglutamyl-aminopeptidase
Cherry red color develops due to hydrolysis of substrate
Findings suggestive of strep pharyngitis:
Sudden onset sore throat; age 5-15; fever; headache; nausea, vomiting / abdominal pain; red swollen tonsils covered with exudate; petechiae on the palate; tender anterior cervical nodes (if not tender, prob not GAS), scarlet fever-like rash, and a history of exposure to someone with GAS pharyngitis.
Findings suggestive of viral pharyngitis
Conjunctivitis, coryza (irritation of mucus membranes in nose), cough, diarrhea, hoarseness, mouth ulcers, and a viral rash.
Why should abdominal exam be done for pharyngitis?
Splenomegaly suggests mononucleosis (EBV)
Tx for GAS pharyngitis
1st line?
Allergy?
1st line is penicillin or amoxicillin.
If allergic use cephalosporin, clindamycin, or macrolide.
What usually causes a peritonsillar abscess?
Anaerobic bacteria
Difference b/w toxic shock and septic shock
Toxic shock is a subset of septic shock.
Septic shock caused by immune system over-responding to an antigen.
Toxic shock is caused directly by the super-antigens.
How does super antigen cause shock?
Locks T cell to APC –> high TNF and IL-1 release
Is bacteremia more common in TSS from Strep or Staph?
Strep
Tx for TSS
- IV fluids to increase BP (most important)
- AB’s – naficillin for S aureus, penicillin G for GAS. Clindamycin for both b/c it decreases production of the toxin (protein synthesis inhibitor).
- Supportive control such as ventilator, dialysis, or blood
- Source control – debridement for Strep, tampon / surgical packing removal for Staph.
What general type of bacteria are most nosocomial infections caused by?
Resistant GNR’s
What does coagulase do?
Converts fibrinogen → fibrin → clot
