Phylum Proteobacteria, Class Gammaproteobacteria, Order Vibrionales, Family Vibrionaceae, Genus Vibrio, Vibrio cholerae Pacini
serogroup “non-O1, non-O139”.
Atypical sucrose negative strains are forming now a separate species - Vibrio mimicus Davis et al. 1982.
Old synonyms: Vibrio cholera Pacini 1854, Kommabacillus Koch 1884, Bacillo virgola del Koch Trevisan 1884, Bacillus cholerae
(Pacini) Trevisan 1884, Bacillus cholerae-asiaticae Trevisan 1884/1885, Pacinia cholerae-asiaticae (Trevisan) Trevisan 1885, Spirillum
cholerae-asiaticae (Trevisan) Zopf 1885, Microspira comma Schroeter 1886, Spirillum cholerae (Pacini) Mace 1889, Vibrio cholerae-
asiaticae (Trevisan) Pfeiffer 1896, Vibrio comma (Schroeter) Blanchard 1906, Liquidovibrio cholerae (Pacini) Orla_Jensen 1909.
Gram-negative, small, straight, slightly curved, curved or comma-shaped rods, 0.5-0.8 x 1.4-2.6 µm. Involution forms occur in old
cultures and under adverse growth conditions. In liquid media is motile by one polar flagella enclosed in a sheath continous with the
outer membrane of the cell wall (Leifson stain). No lateral flagella on solid media.
Fimbriae are produced by V. cholerae O1 and non-O1; these pili are 5-6 nm wide and form bundles of parallel undulating filaments
up to 15 µm long. The protein TcpA from pili is very important because its formation is coregulated with cholera toxin expression and
is a key determinant of in vivo colonization. The gene enconding TcpA reside on a pathogenicity island.
Capsules have been detected at V. cholerae O139 strains.
On first isolation colonies are smooth, glistening, transparent, and by oblique light
show a typical greenish to red-bronze iridescence and fine granular transparency.
Colonial variants are rugose (opaque, usually found in older cultures) or rough, in
response to different growth conditions. V. cholerae produce opaque and translucent
varieties of smooth colonies on heart infusion and meat extract agars. A few strains
produce a brown diffusible melanin-like pigment.
Do not have an absolute requirement for Na+. Can grow on non-selective media
without added salt (e.g. Nutrient agar). Grow in Nutrient broth with 0% NaCl, 1% NaCl,
6% NaCl (variable). No growth in 8-12% NaCl. Can grow at a pH of 10.
Can grow at 30-40 ºC. No growth at 4 ºC.
Facultative anaerobe, chemoorganotrophic.
Most commonly used selective media is Thiosulfate-Citrate-Bile salts-Sucrose
(TCBS) agar. Grows well on blood agar and MacConkey. Biogroup O1 classical is
nonhemolytic but most strains of El Tor biogroup, serogroup O139 and non-O1,
non-O139 are beta-hemolytic on T-soy agar with 5% sheep blood.
Can survive in a “free living state” in both fresh-water and saline environments. Widely distributed in sewage, brackish water, coastal
inlets, estuaries, polluted rivers and lakes. Also exist in an epibiotic form associated with various microscopic organisms
(cyanobacteria, phytoplankton, zooplankton).
May attach to the tissues or chitinous exoskeleton of crustaceans.
Strains of non-O1 V. cholerae greatly outnumber O1 strains in the environment; V. cholerae non-O1 has been recovered from birds,
amphibians, herbivores and freshwater fish.
Sensible to O/129 vibriostatic agent (10 & 150 µg).
V. cholerae causes a diarrhea (infections of gastrointestinal tract) with a wide range of severity (from cholera gravis, pandemic
cholera, to a mild diarrhea with rapid recovery).
Current strains that cause pandemic cholera produce cholera toxin and belong to serogroup O1 and O139; epidemic strains of V.
cholerae O1 are ussualy the El Tor biotype. Non-toxigenic strains of V. cholerae O1 may be isolated from cases of diarrhea and from
environment in areas where cholera is absent.
Majority of V. cholerae non-O1 isolates lacks the classic virulence factors that are present in O1 strains (cholera toxin and the toxin
co-regulated pilus). Non-O1 strains of V. cholerae are involved in septicemia in immunocompromised hosts.
- J.J. Farmer, M. Janda, 2004. Family I. Vibrionaceae. In: Bergey’s Manual of Systematic Bacteriology, Second edition,Vol two, part
B, George M. Garrity (Editor-in-Chief), pp. 491-546.
- J. G.Holt et al., 1994. Group 5 Facultatively anaerobic Gram-negative rods. Subgroup 2 Family Vibrionaceae. In: Begey’s Manual of
Determinative Bacteriology, 9-th edition, Williams & Wilkins. pp. 190-194.
- Judith A. Johnson, 2006. Vibrio. In: Topley & Wilson’s Microbiology and Microbial Infections, 10 edition, Vol. 2, Bacteriology,
Edward Arnold Ltd., 1507-1523.
- Davis, B R, Fanning, G R, Madden, J M, Steigerwalt, A G, Bradford, H B, Jr, Smith, H L, Jr, Brenner, D J. Characterization of
biochemically atypical Vibrio cholerae strains and designation of a new pathogenic species, Vibrio mimicus. J. Clin. Microbiol.
1981 14: 631-639.
Nitrate reduction to nitrite, oxidase, lipase, ONPG, indole production (Hart Infusion Broth 1% NACl), methyl red (1% NaCl), citrate
(Simmons), lysine (1% NaCl), ornithine (1% NaCl), gelatin hydrolysis (1% NaCl, 22 ºC), acid production from D-glucose, D-galactose,
maltose, D-mannitol, sucrose & trehalose are positive.
H2S production in TSI, urea hydrolysis, esculin hydrolysis, phenylalanine deaminase, arginine (1% NaCl), gas production from
D-glucose, acid production from: D-adonitol, L-arabinose, D-arabitol, cellobiose, dulcitol, myo-inositol, lactose, melibiose, raffinose,
L-rhamnose, salicin, D-sorbitol & D-xylose are negative.
Voges-Proskauer (1% NaCl), acid production from glycerol & D-mannose is variable.
(c) Costin Stoica