Cytotoxic and cell vacuolating activity of Vibrio fluvialis isolated from paediatric patients with diarrhoea

Abstract

Vibrio fluvialis is a halophilic Vibrio species associated with acute diarrhoeal illness in humans. It has the potential to cause outbreaks and has an association with paediatric diarrhoea. In this study, 11 V. fluvialis strains isolated from hospitalized patients with acute diarrhoea at the Infectious Diseases Hospital, Kolkata were extensively characterized. All the strains showed growth in peptone broth containing 7 % NaCl. The strains showed variable results in Voges-Proskauer test and to a vibriostatic agent. There was also variation in their antibiograms, and some of the strains were multidrug resistant. Among the 11 strains, two showed only a single band difference in their PFGE profile and the remaining strains showed nine different PFGE patterns. However, unlike PFGE, the strains exhibited close matches and clustering in their ribotype patterns. The haemolytic effect on sheep red blood cells varied with strains. Partial sequence analysis revealed that the V. fluvialis haemolysin gene has 81 % homology with that of the El Tor haemolysin of Vibrio cholerae. A striking finding was the capability of all the strains to evoke distinct cytotoxic and vacuolation effects on HeLa cells. INTRODUCTIONDuring the late 1970s, a previously unidentified group of vibrios was isolated from diarrhoeic stools of infants, children and young adults in Bangladesh (Huq et al., 1980). These vibrios were designated 'group F' vibrios in England (Furniss et al., 1977) and 'CDC group EF6' in the USA (Huq et al., 1980). Taxonomic studies concluded that these organisms represented a new species, and they were designated as Vibrio fluvialis (Lee et al., 1981).The distribution of V. fluvialis is worldwide (McNicol et al., 1980;Thekdi et al., 1982) and this organism is not only isolated from human diarrhoeal cases (Huq et al., 1980;Tacket et al., 1982;Thekdi et al., 1982;Hickman-Brenner et al., 1984;Klontz et al., 1994;Hodge et al., 1995) but also from marine and estuarine environments (Seidler et al., 1980;Lee et al., 1981;Morris & Black, 1985). There are reports of food poisoning caused by this organism (Kobayashi & Ohnaka, 1989;Thekdi et al., 1990), especially due to consumption of raw shellfish (Levine & Griffin, 1993). V. fluvialis is also associated with extraintestinal infections (Yoshii et al., 1987;Albert et al., 1991). The clinical symptoms of the disease include mild to moderate dehydration, vomiting, fever, abdominal pain and diarrhoea (Seidler et al., 1980). The halophilic V. fluvialis (Lee et al., 1981;Lockwood et al., 1982) phenotypically resembles Aeromonas species (Seidler et al., 1980) and taxonomically lies between Aeromonas and Vibrio species (Thekdi et al., 1990). Among the halophilic vibrios, it has close similarity to V. furnissii, but, unlike V. fluvialis, V. furnissii is aerogenic in nature (Brenner et al., 1983).Since V. fluvialis enteritis is reported infrequently, the epidemiology of this infection is not adequately understood. There is very little information available on the virulence factors associated wit...

Identification and Characterization of a Repeat-in-Toxin Gene Cluster in Vibrio anguillarum

“…HlyA shares strong homology (76%) with Vah1 of V. anguillarum. Chakraborty et al (8) also indentified a cytotoxin in V. fluvialis which has 81% homology to HlyA of V. cholerae and also causes the vacuolation of HeLa cells. Taken together, the data strongly suggest that Vah1 of V. anguillarum M93Sm causes vacuolation of ASK cells.…”

Is <i>Vibrio fluvialis</i> Emerging As a Pathogen with Epidemic Potential in Coastal Region of Eastern India Following Cyclone <i>Aila</i>?

“…This also supports the fact that the epidemic in Pakhirala village was different from the other villages. V. fluvialis is generally common in infants, children, and young adults (4,6,7). In the present study, children aged ≤10 years and elderly people aged 55 years or above were more affected than others.…”

Hemorrhagic Bullous Cellulitis/Necrotizing Fasciitis of the Foot due to V. fluvialis and Complicated by E. cloacae Osteomyelitis

“…Due to the infrequent reporting of V. fluvialis, the epidemiology of the infection and the mechanisms of pathogenicity are not sufficiently understood [11,12]. With the rising number of reports of cases of this particular strain of Vibrio, it is expected that more information regarding pathogenesis will be available for physicians in the near future [11].…”

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