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Vibrio

Vibrio

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Encyclopedia
Vibrio is a genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of Gram-negative
Gram-negative
Gram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color...

 bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 possessing a curved rod shape, several species of which can cause foodborne infection, usually associated with eating undercooked seafood. Typically found in saltwater
Seawater
Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% . This means that every kilogram of seawater has approximately of dissolved salts . The average density of seawater at the ocean surface is 1.025 g/ml...

, Vibrio are facultative anaerobes
Facultative anaerobic organism
A facultative anaerobic organism is an organism, usually a bacterium, that makes ATP by aerobic respiration if oxygen is present but is also capable of switching to fermentation...

 that test positive for oxidase
Oxidase
An oxidase is any enzyme that catalyzes an oxidation-reduction reaction involving molecular oxygen as the electron acceptor. In these reactions, oxygen is reduced to water or hydrogen peroxide ....

 and do not form spores. All members of the genus are motile
Motility
Motility is a biological term which refers to the ability to move spontaneously and actively, consuming energy in the process. Most animals are motile but the term applies to single-celled and simple multicellular organisms, as well as to some mechanisms of fluid flow in multicellular organs, in...

 and have polar flagella
Flagellum
A flagellum is a tail-like projection that protrudes from the cell body of certain prokaryotic and eukaryotic cells, and plays the dual role of locomotion and sense organ, being sensitive to chemicals and temperatures outside the cell. There are some notable differences between prokaryotic and...

 with sheaths. Recent phylogenies have been constructed based on a suite of genes (multi-locus sequence analysis).

The name Vibrio derives from Filippo Pacini
Filippo Pacini
Filippo Pacini was an Italian anatomist, posthumously famous for isolating the cholera bacillus Vibrio cholerae in 1854, well before Robert Koch's more widely accepted discoveries thirty years later....

 who isolated microorganisms he called "vibrions" from cholera patients in 1854, because of their motility.

Pathogenic strains


Several species of Vibrio are pathogens. Most disease causing strains are associated with gastroenteritis
Gastroenteritis
Gastroenteritis is marked by severe inflammation of the gastrointestinal tract involving both the stomach and small intestine resulting in acute diarrhea and vomiting. It can be transferred by contact with contaminated food and water...

 but can also infect open wounds and cause septicemia. It can be carried by numerous sea-living animals, such as crabs or prawns, and has been known to cause fatal infections in humans during exposure. Pathogenic Vibrio include V. cholerae
Vibrio cholerae
Vibrio cholerae is a Gram-negative, comma-shaped bacterium. Some strains of V. cholerae cause the disease cholera. V. cholerae is facultatively anaerobic and has a flagella at one cell pole. V...

(the causative agent of cholera
Cholera
Cholera is an infection of the small intestine that is caused by the bacterium Vibrio cholerae. The main symptoms are profuse watery diarrhea and vomiting. Transmission occurs primarily by drinking or eating water or food that has been contaminated by the diarrhea of an infected person or the feces...

), V. parahaemolyticus
Vibrio parahaemolyticus
Vibrio parahaemolyticus is a curved, rod-shaped, Gram-negative bacterium found in brackish saltwater, which, when ingested, causes gastrointestinal illness in humans. V. parahaemolyticus is oxidase positive, facultatively aerobic, and does not form spores...

, and V. vulnificus
Vibrio vulnificus
Vibrio vulnificus is a species of Gram-negative, motile, curved, rod-shaped bacteria of the Vibrio Genus. It was first reported by Hollis et al. in 1976. It was subsequently given the name Beneckea vulnifica by Reichelt et al. in 1976 , and finally Vibrio vulnificus by Farmer in 1979...

.
Vibrio cholerae
Vibrio cholerae
Vibrio cholerae is a Gram-negative, comma-shaped bacterium. Some strains of V. cholerae cause the disease cholera. V. cholerae is facultatively anaerobic and has a flagella at one cell pole. V...

is generally transmitted via contaminated water. Pathogenic Vibrio can cause foodborne infection, usually associated with eating undercooked seafood.

Vibrio vulnificus
Vibrio vulnificus
Vibrio vulnificus is a species of Gram-negative, motile, curved, rod-shaped bacteria of the Vibrio Genus. It was first reported by Hollis et al. in 1976. It was subsequently given the name Beneckea vulnifica by Reichelt et al. in 1976 , and finally Vibrio vulnificus by Farmer in 1979...

outbreaks commonly occur in warm climates and small, generally lethal, outbreaks occur regularly. An outbreak occurred in New Orleans after Hurricane Katrina and several lethal cases occur most years in Florida.

V. parahaemolyticus is also associated with the Kanagawa phenomenon, in which strains isolated from human hosts
Host (biology)
In biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...

 (clinical isolates) are hemolytic
Hemolysis
Hemolysis —from the Greek meaning "blood" and meaning a "loosing", "setting free" or "releasing"—is the rupturing of erythrocytes and the release of their contents into surrounding fluid...

 on blood agar plates, while those isolated from non-human sources are non-hemolytic.

Many Vibrio are also zoonotic. They cause disease in fish and shellfish, and are common causes of mortality among domestic marine life.

Other strains


Vibrio fischeri
Vibrio fischeri
Vibrio fischeri is a gram-negative rod-shaped bacterium found globally in marine environments. V. fischeri has bioluminescent properties, and is found predominantly in symbiosis with various marine animals, such as the bobtail squid. It is heterotrophic and moves by means of flagella. Free living...

, Photobacterium phosphoreum
Photobacterium phosphoreum
Photobacterium phosphoreum or Vibrio phosphoreum is a Gram-negative bioluminescent bacterium living in symbiosis with marine organisms. It can emit bluish-green light thanks to a chemical reaction between FMN, luciferin and molecular oxygen catalysed by an enzyme called Luciferase.- In Popular...

, and V. harveyi are notable for their ability to communicate. Both V. fischeri and Ph. phosphoreum are symbiotes
Symbiosis
Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...

 of other marine organisms (typically jellyfish
Jellyfish
Jellyfish are free-swimming members of the phylum Cnidaria. Medusa is another word for jellyfish, and refers to any free-swimming jellyfish stages in the phylum Cnidaria...

, fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

, or squid
Squid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...

), and produce light via bioluminescence
Bioluminescence
Bioluminescence is the production and emission of light by a living organism. Its name is a hybrid word, originating from the Greek bios for "living" and the Latin lumen "light". Bioluminescence is a naturally occurring form of chemiluminescence where energy is released by a chemical reaction in...

 through the mechanism of quorum sensing
Quorum sensing
Quorum sensing is a system of stimulus and response correlated to population density. Many species of bacteria use quorum sensing to coordinate gene expression according to the density of their local population. In similar fashion, some social insects use quorum sensing to determine where to nest...

. Vibrio harveyi
Vibrio harveyi
Vibrio harveyi is a species of Gram-negative, bioluminescent, marine bacteria in the genus Vibrio. V. harveyi are rod-shaped, motile , facultatively anaerobic, halophilic, and competent for both fermentative and respiratory metabolism. They do not grow at 4°C or above 35°C. V...

is a pathogen of several aquatic animals and notable as a cause of luminous vibriosis in shrimps (prawns)

Flagella


The "typical", early-discovered Vibrio such as V. cholerae
Vibrio cholerae
Vibrio cholerae is a Gram-negative, comma-shaped bacterium. Some strains of V. cholerae cause the disease cholera. V. cholerae is facultatively anaerobic and has a flagella at one cell pole. V...

have a single polar flagellum (monotrichous) with sheath. Some species such as V. parahaemolyticus
Vibrio parahaemolyticus
Vibrio parahaemolyticus is a curved, rod-shaped, Gram-negative bacterium found in brackish saltwater, which, when ingested, causes gastrointestinal illness in humans. V. parahaemolyticus is oxidase positive, facultatively aerobic, and does not form spores...

and V. alginolyticus have both a single polar flagellum with sheath and thin flagella projecting in all directions (peritrichous), and the other species such as V. fischeri have tufts of polar flagella with sheath (lophotrichous).

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