Taxonomy
Morphology
Cultural characteristics
Biochemical characters
Ecology
Pathogenicity
References
Phylum Proteobacteria, Class Gammaproteobacteria, Order Vibrionales, Family Vibrionaceae, Genus Vibrio, Vibrio vulnificus
(Reichelt, Baumann and Baumann 1979) Farmer 1980. Divided in 3 biogroups (1, 2 & 3).
Historical synonyms: Beneckea vulnifica Reichelt, Baumann and Baumann 1979.
Gram-negative, curved rods, motile by monotrichous flagella. Not swarming on
complex media. Fimbriae and capsule are produced. No lateral flagella on solid
media.
Can grow in nutrient broth with: 1% NaCl, 6% NaCl (variable). No growth in 0% NaCl,
8% NaCl, 10% NaCl & 12% NaCl. Growth temperature 30-40 ºC. No growth at 4 ºC.
On blood agar, tends to form smooth, creamy, buff-colored colonies, alpha-hemolytic
or nonhemolytic. May produce opaque and translucent varieties of smooth colonies
on common media.
Green colonies on TCBS agar.
Occurs in human clinical specimens and in marine environments (seawater, crustacean, and estuarine fish. Bacteriophage have
been found in Vibrio vulnificus.
Cause wound infections (result from direct inoculation after contact with marine animals or the marine or estuary environment),
bacteremia and septicemia (associated with the consumption of raw oysters). Rare complications of V. vulnificus include meningitis,
myositis, endometritis, peritonitis, and ocular disease.
V. vulnificus is responsible for more than 90% of deaths due to vibrios.
Strains of biogroup 2 were originally shown to be pathogenic for eels; biogroup 2 is a cause of human wound as well.
Biogroup 3 was associated with human wound infections and exposure to cultured Tilapia spp.
Fimbriae are produced;they may be involved in colonization.
A polysaccharide capsule is produced
An unique V. vulnificus cytotoxin-hemolysin apparently does not play a major role in pathogenesis
Other virulence factors include iron-scavenging systems and resistance to complement-mediated lysis
V. vulnificus has seven O antigen groups.
- 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.
- West, P. A., Brayton, P. R., Bryant, T. N., Colwell, R. R. Numerical Taxonomy of Vibrios Isolated from Aquatic Environments. Int J
Syst Bacteriol 1986 36: 531-543.
Positive results for indole (Heart Infusion Broth, 1% NaCl; biogroup 2 is negative), methyl red (1% NaCl), citrate utilization / Simmons
(biogroup 3 is negative), lysine (1% NaCl), ornithine (1% NaCl) (biogroup 2 is negative), gelatin hydrolysis (1% NaCl, 22 °C), nitrate
reduction to nitrite, oxidase, lipase, ONPG test (biogroup 3 is negative), acid production from D-glucose, cellobiose (biogroup 3 is
negative), D-galactose, lactose (biogroup 3 is negative), maltose, D-mannitol (biogroup 2 & 3 are negative), D-mannose, salicin
(biogroup 3 is negative), D-sorbitol (biogroup 1 & 3 are negative) & trehalose.
Negative results for Voges-Proskauer (1% NaCl), H2S on TSI, urea hydrolysis & arginine (1% NaCl), gas production from D-glucose,
acid production from: D-adonitol, L-arabinose, D-arabitol, dulcitol, glycerol, myo-inositol, raffinose, L-rhamnose, sucrose & D-xylose.
Variable results for phenylalanine deaminase, esculin hydrolysis & acid production from melibiose.
(c) Costin Stoica