Vibrio, Aeromonas, Plesiomonas, & Campylobacter

Gram negative rods with polar, sheathed flagella in broth but peritrichous, unsheathed flagella on solid media
Rods are “curved” in clinical specimens, but small, straight rods after culture
Facultatively anaerobic
Asporogenous

Most are oxidase positive and able to reduce nitrates to nitrites
All are susceptible to vibriostatic compound O/129
Most exhibit a mucoid “stringing” reaction when colonies mixed with sodium desoxycholate
Except for V. cholerae and V. mimicus, all are halophilic (salt-loving)
Some strains can be serotyped
Vibrio species can be isolated from a variety of clinical specimens, including feces, wound, and blood
Major species are V. cholerae, V. parahaemolyticus, V. vulnificus, and V. alginolyticus

cholerae O1 is causative agent of cholera
- Also known as Asiatic cholera or epidemic cholera; particularly prevalent in India and Bangladesh
- Also seen along the Gulf coast of the U.S.

Acute diarrheal disease
Spread through contaminated water, but also improperly preserved foods, including fish and seafood, milk, ice cream, and unpreserved meat
“Rice Water” stools
- Caused by cholera toxin or choleragen
- Dehydration is usual cause of death

Second most common Vibrio species involved in gastroenteritis
“Summer diarrhea” in Japan
Most cases traced to recent consumption of raw, improperly cooked, or recontaminated seafood, especially oysters
Gastrointestinal symptoms are generally self-limiting; watery diarrhea, moderate cramps or vomiting

Found in marine environments along all coasts in the U.S.
Two categories of infections
- Primary septicemia following consumption of contaminated shellfish, especially raw oysters; patients with liver dysfunction that results in increased levels of iron are predisposed
- Wound infections following traumatic aquatic wound

Ubiquitous oxidase-positive, glucose-fermenting, motile, not curved gram-negative rods widely distributed in fresh and salt water environments
Isolated from produce and meat sources

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