Vibrio is a genus of Gram-negative bacteria, possessing a curved-rod shape,
several species of which can cause foodborne infection, usually associated
with eating undercooked seafood. Typically found in salt water, Vibrio
species are facultative anaerobes that test positive for oxidase and do not
form spores. All members of the genus are motile and have polar flagella with
sheaths. Recent phylogenies have been constructed based on a suite of genes.
The name Vibrio derives from Filippo Pacini, who isolated micro-organisms 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, but can
also infect open wounds and cause septicemia. They can be carried by
numerous marine animals, such as crabs or prawns, and have been known to cause
fatal infections in humans during exposure. Pathogenic Vibrio species
include V. cholerae, V. parahaemolyticus, and V. vulnificus. V.
cholerae is generally transmitted by contaminated water. Pathogenic Vibrio
species can cause foodborne illness, usually associated with eating
undercooked seafood. The pathogenic features can be linked to quorum sensing
where bacteria are able to express their virulence factor via their signalling
molecules. V. vulnificus 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. As of 2013 in the United States, Vibrio
infections as a whole were up 43% when compared with the rates observed in
2006-2008. V. vulnificus, the most severe strain, has not increased.
Foodborne Vibrio infections are most often associated with eating raw
shellfish. V. parahaemolyticus is also associated
with the Kanagawa phenomenon, in which strains isolated from human hosts are
hemolytic on blood agar plates, while those isolated from nonhuman sources are
not hemolytic. Many Vibrio species are also zoonotic.
They cause disease in fish and shellfish, and are common causes of
mortality among domestic marine life. Treatment
Medical care depends on the clinical presentation and the presence of
underlying medical conditions. = Vibrio gastroenteritis=
Because Vibrio gastroenteritis is self-limited in most patients, no
specific medical therapy is required. Patients who cannot tolerate oral fluid
replacement may require intravenous fluid therapy.
Although most Vibrio species are sensitive to antibiotics such as
doxycycline or quinolones, antibiotic therapy does not shorten the course of
the illness or the duration of pathogen excretion. However, if the patient is
ill and has a high fever or an underlying medical condition, oral
antibiotic therapy with doxycycline or quinolone can be initiated.
= Noncholera Vibrio infections= Patients with noncholera Vibrio wound
infection or septicemia are much more ill and frequently have other medical
conditions. Medical therapy consists of: Prompt initiation of effective
antibiotic therapy Intensive medical therapy with
aggressive fluid replacement and vasopressors for hypotension and septic
shock to correct acid-base and electrolytes abnormalities that may be
associated with severe sepsis Early fasciotomy within 24 hours after
development of clinical symptoms can be life-saving in patients with necrotizing
fasciitis. Early debridement of the infected wound
has an important role in successful therapy and is especially indicated to
avoid amputation of fingers, toes, or limbs.
Expeditious and serial surgical evaluation and intervention are required
because patients may deteriorate rapidly, especially those with
necrotizing fasciitis or compartment syndrome.
Reconstructive surgery, such as skin graft, is indicated in the recovery
phase. Other strains
V. harveyi is a pathogen of several aquatic animals, and is notable as a
cause of luminous vibriosis in shrimp Flagella
The "typical", early-discovered Vibrio species, such as V. cholerae, have a
single polar flagellum with sheath. Some species, such as V. parahaemolyticus and
V. alginolyticus, have both a single polar flagellum with sheath and thin
flagella projecting in all directions, and the other species, such as V.
fischeri, have tufts of polar flagella with sheath.
See also Cholera toxin
References External links
Vibrio genomes and related information at PATRIC, a Bioinformatics Resource
Center funded by NIAID Bacteriological Analytical Manual Online
Association of Vibrio Biologist