Vibrionaceae

Taxobox
color = lightgrey
name = Vibrionaceae
regnum = Bacteria
phylum = Proteobacteria
classis = Gamma Proteobacteria
ordo = Vibrionales
familia = Vibrionaceae
familia_authority = Véron 1965
subdivision_ranks = Genera
subdivision ="Allomonas"
"Beneckea"
"Enhydrobacter"
"Listonella"
"Lucibacterium"
"Photobacterium"
"Salinivibrio"
"Vibrio"

The Vibrionaceae are a family of Proteobacteria, given their own order. Inhabitants of fresh or salt water, several species are pathogenic, including the type species "Vibrio cholerae", which is the agent responsible for cholera. Most bioluminescent bacteria belong to this family, and are typically found as symbiotes of deep-sea animals. [cite book | author = Madigan, Michael; Martinko, John (editors) | title = Brock Biology of Microorganisms | edition = 11th ed. | publisher = Prentice Hall | year = 2005 | id = ISBN 0-13-144329-1 ]

"Vibrionaceae" are Gram-negative organisms and facultative anaerobes, 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" 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 six validly published genera: "Aliivibrio"cite journal |author=Urbanczyk H, Ast J, Higgins M, Carson J, Dunlap P |title= Reclassification of "Vibrio fischeri, Vibrio logei, Vibrio salmonicida" and "Vibrio wodanis" as "Aliivibrio fischeri" gen. nov., comb. nov., "Aliivibrio logei" comb. nov., "Aliivibrio salmonicida" comb. nov. and "Aliivibrio wodanis" comb. nov|journal=International Journal of Systematic and Evolutionary Microbiology|volume=57 |issue=12 |pages=2823–2829 |year=2007 |doi= 10.1099/ijs.0.65081-0 |pmid= 18048732] , "Salinivibrio", "Enterovibrio", "Grimontia", "Photobacterium" and "Vibrio".

Members of this family also synthesize Tetrodotoxin, an ancient marine alkaloid and powerful neurotoxin (Na+ pump inhibitor, 1 mg can kill an adult) that serves to protect members of the Tetraodontiformes ("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. [cite web |author=Johnson J| url=http://www.chm.bris.ac.uk/motm/ttx/ttx.htm |title=Tetrodotoxin |format= |work=Molecule of the Month| date=2002-01-05 |accessdate=2008-10-07] 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 a good example 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. [cite web |author=Edwards N |url=http://www.bristol.ac.uk/Depts/Chemistry/MOTM/stx/saxi1.htm |work=Molecule of the Month | title=Saxitoxin |date=1998-08-18 |accessdate=2008-10-07]

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 gastro-enteritis and V. vulnificus that can lead to acute and fatal septicaemia. 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. [cite book | author = Thompson, Fabiano; Austin, Brian; Jean Swings (editors) | title = The Biology of Vibrios| edition = 1st ed. | publisher = American Society for Microbiology| year = 2006 | isbn=9781555813659] 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, the plant symbiont of coral. These species of vibrio are thought to be a cause of coral bleaching cite journal |author=Ben-Haim, Y, Zicherman-Keren, M & Rosenberg, E |title= Temperature-regulated bleaching and lysis of the coral "Pocillopora damicornis" by the novel pathogen "Vibrio coralliilyticus" |journal=Applied & Environmental Microbiology |volume=69 |issue=7 |pages=4236–4242 |year=2004 |doi= 10.1128/AEM.69.7.4236-4242.2003 |pmid= 12839805] cite book | author = Rosenberg, Eugene; Loya, Yossi | title = Coral Health and Disease| edition = 1st ed. | publisher = Springer| year = 2004 | isbn=3540207724]

References