Vibrio parahaemolyticus and V. vulnificus. Plesiomonas and Aeromonas

Question 1

General features and habitat of Vibrionaceae Family

Answer 1

Gram negative, curved rods (comma)

Facultative anaerobic rods with oxidase positive (differential diagnosis from Enterobacteriaceae which are oxidase negative)

Primarily found in water (organism can multiply freely in water)

Question 2

Vibrio parahaemolyticus

Answer 2

Transmitted by consumption of contaminated shellfish not properly cooked (e.g. Asian cuisine) or from contaminated sea water

Has enterotoxin

Incubation time of around 24 hours

Causing self-limiting but severe gastroenteritis with diarrhea

Can also cause wound infection in sea water (multiple well in sea water)

Cultured on TCBS medium

Question 3

Vibrio vulnificus

Answer 3

Transmitted by consumption of contaminated shellfish not properly cooked (e.g. Asian cuisine) or from contaminated sea water

Virulence factors: capsule, cytolysins, collagenase, protease, siderophores (iron-carrier enzyme)

Cause:
Severe wound infections- erythema, bullae formation and necrosis

Sepsis (septicemia)- after ingesting raw shellfish

Question 4

Plesiomonas (e.g. P. shigelloides)

Answer 4

Gram negative, motile, oxidase positive, rod shaped

Transmitted by seafood (foodborne)

Clinical feature- gastroenteritis with watery or bloody diarrhea

Question 5

Aeromonas (e.g. A. hydrophila)

Answer 5

Gram negative
rod shape
facultative anaerobic
oxidase positive

Transmitted by meat and dairy products (foodborne)

Opportunistic systemic disease in immunocompromised patients

Diarrheal disease- bloody diarrhea (from contaminated food, water)

Wound infections- cellulitis (from contaminated water)

Treatment: Ciprofloxacin