cholera, campylobacter, helicobacter Flashcards
is cholera motile?
yes
cholera gram negative or positive?
negative
what is cholera’s shape?
comma shaped, polar flagellum
what antigens are associated with cholera?
O and H
what toxins does cholera produce?
endotoxin and exotoxin (cholera toxin)
what is the major colonization factor for cholera?
toxin coregulated pilus (TCP)
important aspects of cholera pathogenesis
- TCP is expressed and bacteria form micro colonies in intestinal crypts
- cholera toxin binds to GM1 gangliosides of cell membrane
- neuramidase converts other gangliosides to GM increasing toxin binding sites
- cholera toxin induces cAMP and adenylate cyclase production
two mechanisms for fluid loss in cholera
1) villus cells decrease NaCl absorption from gut
2) secretory cells increase Cl and HCO3 secretion into gut, H2O follows
clinical features of cholera
- painless, odorless watery diarrhea
- dehydration, low BP
- high electrolytes in stool
cholera treatment
- fluid and electrolyte replacement
- antibiotics reduce duration of diarrhea
- doxycycline for adults, azithromycin for children and pregnant women
campylobacter shape
curved, comma
campylobacter incubation period
3-5 days
what is Guillaim-Barre Syndrome?
- caused by 1/1000 cases of campylobacter
- development of autoimmunity to own nerves, paralysis that lasts several weeks
campylobacter infectious dose
500 orgs
campylobacter treatment
- fluids
- erythromycin, ciprofloxacin
