Vibrio

Question 1

Shape?

Answer 1

Curved, Gram Negative rods. Oxidase positive.

Question 2

Can they move?

Answer 2

Yes. Motile via polar flagella.

Question 3

What environment are they found in?

Answer 3

Saltwater. Warm months allows more to survive…thus disease occurs in warm months. Don’t eat oysters in the summer.

Question 4

What are the 3 significant Vibrio human pathogens?

Answer 4

1. V. cholerae
2. V. parahaemolyticus
3. V. vulnificus

Question 5

Where is cholera endemic?

Answer 5

Asia, Africa, South America, and Rutvi’s homeland

Question 6

How is cholera spread?

Answer 6

Contaminated water and food

Question 7

What carries cholera?

Answer 7

Humans and environmental reservoirs

Question 8

What serogroups of V. cholerae are responsible for epidemic and pandemic cholera?

Answer 8

O1 and O139

Question 9

What are the 2 subtypes of the O1 serogroup of V. cholera?

Answer 9

1. El Tor

2. Classical

Question 10

What is the incubation period of V. cholera?

Answer 10

2-3 days after ingestion of contaminated source

Question 11

Dose of cholera required to be infectious?

Answer 11

Very high: >10^8 CFU

Question 12

Clinical presentation of cholera?

Answer 12

1. Abrupt onset of vomiting and high volume watery diarrhea (20 L/day)
2. Rice-water stools: speckled w/ mucus and loaded w/ bugs

Question 13

What causes the high volume watery diarrhea of cholera?

Answer 13

Cholera toxin (chloride channel activation)

Question 14

What do cholera patients usually die of?

Answer 14

Dehydration b/c they shit their brains out

Question 15

Virulence factors of V. cholera?

Answer 15

1. TCP: PAI-encoded pilus

2. Phage-encoded toxin

Question 16

What are the characteristics of cholera toxin?

Answer 16

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

Question 17

Diagnosis of cholera?

Answer 17

Stool culture on TCBS (Thiosulfate Citrate Bile salts Sucrose) or MacConkey agars

Question 18

Treatment of cholera?

Answer 18

1. Oral Rehydration Therapy

2. Doxy or Erythromycin

Question 19

What does V. parahaemolyticus cause?

Answer 19

Seafood-associated food poisoning. MC in Japan. Gulf and Pacific coasts of US in the warm months.

Question 20

Clinical presentation of V. parahaemolyticus infection?

Answer 20

1. Watery diarrhea often w/ abdominal cramps
2. N/V
3. Low grade fever

Question 21

How long after exposure to V. parahaemolyticus will symptoms develop?

Answer 21

24 hours

Question 22

Treatment for V. parahaemolyticus?

Answer 22

Usually self-limiting. Tx rarely needed.

Question 23

What do V. parahaemolyticus and V. vulnificus have in common?

Answer 23

Both are free living in sea water

Question 24

How is V. vulnificus spread?

Answer 24

Consumpiton of raw oysters or wound infection (cellulitis)

Question 25

What is the clinical presentation of V. vulnificus infection?

Answer 25

1. Vomiting 2. Diarrhea 3. Abdominal cramps Rare infection but 20% mortality rate.

Question 26

How can V. vulnificus manifest in immunocompromised or chronic liver patients?

Answer 26

1. Septicemia | 2. Bullae

Question 27

Treatment of V. vulnificus?

Answer 27

Doxy