ch 20
No description yet. This curated deck is ready for daily study.
Card preview (9)
What is an endotoxin and how is it different from exotoxins/enterotoxins?
Endotoxin is the lipid A portion of LPS in gram-negative bacteria. It is released during cell lysis and triggers strong pro‑inflammatory cytokine responses (fever, shock). Exotoxins/enterotoxins are secreted proteins with specific targets.
What disease is caused by Bordetella pertussis?
Pertussis (whooping cough)
What vaccine protects against pertussis?
Acellular pertussis vaccine (DTaP for infants, Tdap booster for teens/adults).
What problems are NDM-1 and KPC associated with?
-Antibiotic resistance enzymes -Break down beta-lactam antibiotics
What are coliforms? Which species is used as an indicator organism for fecal contamination in water?
Lactose-fermenting gram-negative rods E. coli = indicator of fecal contamination
How can an EMB plate or Hektoen plate be used to differentiate coliforms and noncoliforms?
EMB E. coli → metallic green sheen Non-coliforms → colorless Hektoen Salmonella → black colonies (H₂S+) E. coli → no black precipitate
What are the H, K, O antigens in gram-negative bacteria?
H – flagellar K – capsule O – cell wall (LPS)
What is the difference between an enterotoxigenic and an enteroinvasive infection?
Enterotoxigenic (ETEC, EHEC) → toxin-mediated diarrhea Enteroinvasive (Salmonella) → invade intestinal cells, inflammation