Flashcards in Microbiology: Bacterial Deck (241)
Two toxins produced by C. difficile:
What kind of toxin? What is its function?
Toxin A = enterotoxin = exotoxin, binds brush border.
Toxin B = cytotoxin = destroys enterocyte cytoskeleton -> pseudomembranous colitis.
Two antibiotics especially associated with C. diff:
Treatment for C. diff:
Dx of C. diff:
Toxin in stool
Most common E. coli strain causing bloody diarrhea:
Treatment for dysentery caused by E. coli:
Two toxins produced by enterotoxigenic E. coli:
Second messenger inside the cell for action of each?
Heat labile = cAMP increase = watery diarrhea like cholera
Heat stable = cGMP increase
Cause of traveler's diarrhea ("Montezuma's revenge"):
Enterotoxigenic E. coli
E. coli strain causing diarrhea in daycare:
Enterohemorrhagic E. coli
Triad of HUS:
Explain how this happens:
Acute renal failure
Shiga-like toxin from EHEC 0157:H7 damages endothelium, which swells, cuts off blood flow to the kidney. Narrow vessels shear RBC -> mechanical hemolysis. Damaged endothelium consumes the platelets -> thrombocytopenia.
Most E. coli ferment this sugar:
Which one does not?
EHEC does not ferment sorbitol
Tx for HUS:
Do not give abx.
Two E. coli strains causing dysentery:
E. coli strain causing watery diarrhea:
How would you distinguish EHEC from other forms of E. coli on culture?
It does not ferment sorbitol. The others do.
Organism responsible for causing staghorn calculi:
Urease-positive, ammonium-Mg-phosphate stones:
Common cause of osteomyelitis in sickle cell patients:
Four A's of Klebsiella:
Abscesses in lungs and liver
Mucoid colonies, lobar pneumonia in a diabetic:
Flagellated organism, hematogenous dissemination, produces H2S:
Very virulent organism, frequently causes bloody diarrhea, human and primate but not pet reservoirs:
Associated with Reiter syndrome:
Rose spots on abdomen:
Carried in the gallbladder, found only in humans:
Which organism ferments lactose: Salmonella or Shigella?
Which organism produces H2S: Salmonella or shigella?
Which organism produces a monocytic response: Salmonella or Shigella? A PMN response?
Monocytes = Salmonella
PMNs = Shigella