Flashcards in Vibrio Deck (27)
Curved, Gram Negative rods. Oxidase positive.
Can they move?
Yes. Motile via polar flagella.
What environment are they found in?
Saltwater. Warm months allows more to survive...thus disease occurs in warm months. Don't eat oysters in the summer.
What are the 3 significant Vibrio human pathogens?
1. V. cholerae
2. V. parahaemolyticus
3. V. vulnificus
Where is cholera endemic?
Asia, Africa, South America, and Rutvi's homeland
How is cholera spread?
Contaminated water and food
What carries cholera?
Humans and environmental reservoirs
What serogroups of V. cholerae are responsible for epidemic and pandemic cholera?
O1 and O139
What are the 2 subtypes of the O1 serogroup of V. cholera?
1. El Tor
What is the incubation period of V. cholera?
2-3 days after ingestion of contaminated source
Dose of cholera required to be infectious?
Very high: >10^8 CFU
Clinical presentation of cholera?
1. Abrupt onset of vomiting and high volume watery diarrhea (20 L/day)
2. Rice-water stools: speckled w/ mucus and loaded w/ bugs
What causes the high volume watery diarrhea of cholera?
Cholera toxin (chloride channel activation)
What do cholera patients usually die of?
Dehydration b/c they shit their brains out
Virulence factors of V. cholera?
1. TCP: PAI-encoded pilus
2. Phage-encoded toxin
What are the characteristics of cholera toxin?
1. Lysogenic phage encoded
2. AB toxin composed of 5 B's and 1 A subunit
3. ADP-ribosylates GTP-binding protein which causes activation of AC...cAMP....Cl channel activation
Diagnosis of cholera?
Stool culture on TCBS (Thiosulfate Citrate Bile salts Sucrose) or MacConkey agars
Treatment of cholera?
1. Oral Rehydration Therapy
2. Doxy or Erythromycin
What does V. parahaemolyticus cause?
Seafood-associated food poisoning. MC in Japan. Gulf and Pacific coasts of US in the warm months.
Clinical presentation of V. parahaemolyticus infection?
1. Watery diarrhea often w/ abdominal cramps
3. Low grade fever
How long after exposure to V. parahaemolyticus will symptoms develop?
Treatment for V. parahaemolyticus?
Usually self-limiting. Tx rarely needed.
What do V. parahaemolyticus and V. vulnificus have in common?
Both are free living in sea water
How is V. vulnificus spread?
Consumpiton of raw oysters or wound infection (cellulitis)
What is the clinical presentation of V. vulnificus infection?
3. Abdominal cramps
Rare infection but 20% mortality rate.
How can V. vulnificus manifest in immunocompromised or chronic liver patients?