The Vibrionaceae are a family of Pseudomonadota given their own order, Vibrionales. Inhabitants of fresh or salt water, several species are

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...

ic, including the type species ''

Vibrio cholerae ''Vibrio cholerae'' is a species of Gram-negative, facultative anaerobe and comma-shaped bacteria. The bacteria naturally live in brackish or saltwater where they attach themselves easily to the chitin-containing shells of crabs, shrimps, and oth ...

'', which is the agent responsible for cholera. Most bioluminescent bacteria belong to this family, and are typically found as

symbiont Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasi ...

s of deep-sea animals. Vibrionaceae are

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wa ...

organisms and

facultative anaerobe A facultative anaerobic organism is an organism that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation if oxygen is absent. Some examples of facultatively anaerobic bacteria are '' Staphylococc ...

s, capable of fermentation. They contain oxidase and have one or more flagella, which are generally polar. Originally, these characteristics defined the family, which was divided into four genera. Two of these, ''

Vibrio ''Vibrio'' is a genus of Gram-negative bacteria, possessing a curved-rod (comma) shape, several species of which can cause foodborne infection, usually associated with eating undercooked seafood. Being highly salt tolerant and unable to survive ...

'' and '' Photobacterium'', correspond to the modern group, although several new genera have been defined. Genetic studies have shown the other two original members—'' Aeromonas'' and '' Plesiomonas''—belong to separate families. The family Vibrionaceae currently comprises eight validly published genera: ''Aliivibrio'', ''Catenococcus'', ''Enterovibrio'', ''Grimontia'', ''Listonella'', ''Photobacterium'', ''Salinivibrio'', and ''Vibrio''; although the status of ''Listonella'' has been questioned. Members of this family also synthesize tetrodotoxin (TTX), an ancient marine

alkaloid Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar ...

and powerful neurotoxin (Na+ pump inhibitor, 1 mg can kill an adult) that serves to protect members of an order of fishes, the

Tetraodontiformes The Tetraodontiformes are an order of highly derived ray-finned fish, also called the Plectognathi. Sometimes these are classified as a suborder of the order Perciformes. The Tetraodontiformes are represented by 10 extant families and at least ...

(''tetras''-four and ''odontos''-tooth), which include the puffer fish (see fugu, raw puffer fish served in Japan). As mentioned above, Vibrionaceae bacteria are in symbiosis with many marine organisms. In the case of the puffer fish, and other marine organisms harboring TTX-producing Vibrionaceae, the symbiosis is an ancient and powerful one, providing protection against predation for the marine organisms that harbor these bacteria, while providing the bacteria a protected environment with plenty of nutrients for growth. TTX and saxitoxin provide good examples of convergent biochemical evolution: both toxins are extremely toxic at low levels, both are Na⁺ pump inhibitors and both have nearly identical binding constants on the Na⁺ pump in neurons.

Pathology

A characteristic of the family is the broad host range susceptible to infection by vibrios. Pathogens of man, other than ''V. cholerae'', include '' V. parahaemolyticus'', a cause of gastroenteritis and '' V. vulnificus'' that can lead to acute and fatal

septicaemia Sepsis, formerly known as septicemia (septicaemia in British English) or blood poisoning, is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage is follo ...

. Other species of Vibrionaceae are associated with disease in a wide variety of finfish, one of the most notable and commonly occurring pathogens being '' Vibrio anguillarum'', the cause of septicaemia in farmed salmonids such as Atlantic salmon and rainbow trout. Species such as '' V. tubiashii'' cause disease in larval stages of Pacific oyster (''Crassostrea gigas'') while '' V. harveyi'' causes luminous vibriosis in penaeid shrimps (prawns). The extent of the host range is seen with species such as ''V. mediterranei'' and ''V. coralliilyticus'', which can infect

zooxanthellae Zooxanthellae is a colloquial term for single-celled dinoflagellates that are able to live in symbiosis with diverse marine invertebrates including demosponges, corals, jellyfish, and nudibranchs. Most known zooxanthellae are in the genus ''S ...

, the plant symbionts of coral. These species of ''Vibrio'' are thought to be a cause of coral bleaching.

References

{{Taxonbar, from=Q910922 Bacteria families