Bacteria Flashcards
What are the four main bacterial pathogens associated with intoxications
Staph aureus
Clostridium perfringens
Clostridium botulinum
Bacillus cereus
How does C. perf work?
enymatic lysis: alpha toxin hydrolyses phosphorylchlorine in cell membrane –> lysis –> cell death
reheating food - spores still survive
how does staph aureus work?
alpha toxin –> binds to membrane protein–> forms heptamer, making beta-barrel pore in the membrane;
infection is due to preformed toxin
how does C. diphth work?
potent exotoxin inhibits protein synthesis via EF-2
how does vibrio cholerae work?
toxin permanently activates Gs, increases cAMP
how does C. tetani work?
produces tetanospasmin, exotoxin blocks inhibitor transmitter release – continuous stimulation
how does c. botulinum work?
preformed, LT toxin that inhibits the release of ACh
How does bacillus cereus cause food poisoning?
spores survive cooking rice
nausea and vomitting within 1-5 hours
diarrhea - 8-18 hours
“reheated rice”
what toxin is associated with vomiting in Bacillus cereus
heat-stable; associated with reheating rice
what toxin is associated with diarrhea in Bacillus cereus
heat-liable
what types of patients can salmonella become invasive in?
immunocompromised
children
sickle-cell
what can invasive salmonella cause
septicaemia, sometimes leading to osteomyelitis, pneumonia, or meningitis
