L51 Flashcards
What are essential virulence factors for vibrio cholerae?
CT = cholera toxin TCP = toxin co-regulated pilus
How is cholera transmitted?
Contaminated water
Contaminated food from fecal-oral
Which drug can you use to shorten the time of cholera?
Tetracycline
- Azythro
- Doxy
Explain cholera pathogenesis.
@ Prox SI Stays in lumen - tethers to the SI wall Secrete cholera toxin - Increased cAMP - Excrete Cl- into lumen - Less Na absorbed --> NaCl into lumen - Water follows osmotic gradient
Explain the cholera toxin mechanism.
5B, 1A subunit From bacteriophage ADP ribosylates - adenylate cyclase always on --> increased cAMP Opens CFTR - Cl- out into lumen Can't absorb Na b/c Na/Cl co-transport
What is the role of toxin co-regulated pilus?
Essential virulence via colonization
Encoded by PI
What regulates the activity of cholera’s virulence factors?
ToxR
What is the composition of the cholera toxin?
B subunit - is the non-toxic, immune subunit
What does vibrio parahaemolyticus cause?
Diarrhea from seafood
- Watery
What is the virulence mechanism of V.parahae?
Enterotoxin
- Uncommon in isolates, but amplified and selected for to cause disease
T3SS
What does V.vulnificus cause?
Cellulitis –> maybe bacteremia
Exposure to seawater/eating seafood
CAN PROGRESS TO DEATH
What are the virulence mechanism for V.vulnificus?
Polysacc capsule
Endotoxin –> shock
Treat V.vulnificus
Debridement
Tetracycline + ciprofloxacin
Where do you find aeromonas?
Water & soil
What does aeromonas cause?
Wound infections –> cellulitis –> maybe bacteremia (if person also has h/o cancer)
Acute diarrheal disease, but also many people are asymptomatic carriers
