FSC-342 Midterm: Lecture 17 - Vibrio

Where are Vibrio species commonly found in the environment?

Estuarine and brackish water

Which seafoods are commonly associated with Vibrio?

Raw oysters, shrimp, clams, and coastal fish

What is the morphology of Vibrio species?

Gram-negative, straight or comma-shaped rods

How do Vibrio species move?

Motile by a single polar flagellum

Are Vibrio species oxidase and catalase positive?

Yes

When are Vibrio infections more common?

During warm weather months (April to October)

Where in the U.S. are Vibrio infections most common?

Warm East Coast and Gulf waters

What are the main transmission routes of Vibrio?

Consumption of seafood and exposure of wounds to seawater

Who is most at risk of Vibrio infection?

Immunocompromised individuals

What are common symptoms of Vibrio infections?

Watery diarrhea, cramps, nausea, vomiting, chills

Which Vibrio species causes cholera?

Vibrio cholerae

Which serogroups of V. cholerae are responsible for epidemics and pandemics?

O1 and O139

What toxin is produced by epidemic strains of V. cholerae?

Cholera toxin (CT)

What does cholera toxin do?

Disrupts ion transport in the intestinal epithelium, causing massive fluid loss

What is a classic symptom of severe cholera infection?

Profuse "rice water" diarrhea

What type of illness is caused by non-O1/non-O139 strains of V. cholerae?

Mild to moderate gastroenteritis

What is the incubation time for V. cholerae?

Several to 120 hours

What is the growth temperature range for V. cholerae?

8–42°C

What is the NaCl tolerance range for V. cholerae?

0–6%

How long can V. cholerae survive in seawater?

7 days

How long can V. cholerae survive in shellfish?

Weeks

What is the CDC prevention recommendation for cholera?

“Boil it, cook it, peel it or forget it”

Which Vibrio species causes gastroenteritis and is the most widely distributed Vibrio pathogen?

Vibrio parahaemolyticus

How many U.S. cases were estimated in 2011 from V. parahaemolyticus?

4,500 cases

What is the growth temperature range for V. parahaemolyticus?

5–44°C (optimum 30–35°C)

Does V. parahaemolyticus require salt for growth?

Yes

What is the NaCl growth range for V. parahaemolyticus?

1–8% (optimum 2–4%)

What is the pH growth range for V. parahaemolyticus?

pH 5–11 (optimum 7.5–8.6)

Is V. parahaemolyticus heat sensitive?

Yes, killed at 60°C (15–30 min) or 100°C (1–5 min)

What virulence factor is correlated with V. parahaemolyticus pathogenicity?

Beta-hemolysin

What is the main reservoir for V. parahaemolyticus?

Seafood (oysters, crab, shrimp, lobster)

What is the infectious dose and onset time for V. parahaemolyticus?

High infectious dose; onset 4–30 hours (median 24 h)

What is the duration of V. parahaemolyticus illness?

3–7 days

What foods caused a multistate outbreak in 2013 involving V. parahaemolyticus?

Raw oysters and clams along the Atlantic coast

Which Vibrio species causes septicemia and the most severe infections?

Vibrio vulnificus

What food is most associated with V. vulnificus infection?

Raw oysters

How can V. vulnificus enter through wounds?

Through minor skin breaks, leading to necrotizing infections

What is the fatality rate for raw oyster–associated V. vulnificus infections?

60%

What is the incubation period for V. vulnificus?

6–72 hours (median 24 hours)

What are common symptoms of V. vulnificus infection?

Fever, chills, nausea, hypotension (sometimes GI symptoms)

Where is V. vulnificus commonly found?

Estuaries on Gulf, East, and Pacific Coasts

What is the seasonality of V. vulnificus infections?

Summer months (May–August)

How can V. vulnificus be controlled or inactivated?

Freezing, low-temp pasteurization, mild heat, high pressure processing