Ecology and distribution of toxigenic Vibrio cholerae in aquatic environments of a temperate region.

The occurrence of a human pathogen, Vibrio cholerae, in aquatic environments and the distribution of toxigenic strains were studied for 2 years. The pathogen was isolated from freshwater, brackish and marine environments. V. cholerae non-01 was frequently recovered but the 01 serogroup was not detected. Of the 57 environmental strains tested, eight (12%) were found to be potentially toxigenic. A number of atypical V. cholerae 01 strains were found which showed higher virulence potentials than the serogroup non-01 strains. A significant correlation of the incidence of the pathogen was noted with water temperature in freshwater environments. In marine environments, a reciprocal correlation of the V. cholerae count and salinity was observed. The present study describes the ecology of V. cholerae in aquatic environments of a temperate region and notes that the occurrence of potentially virulent strains could be of public health significance.