Potentially pathogenic vibrios in brackish waters and mussels

Water and mussel samples were collected from two brackish lakes, used as mu ssel farms, at different times of the year, for the quantitative analysis o f Vibrio spp. and for the isolation of potentially pathogenic species. The isolates underwent cultural and biochemical tests selected for rapid identi fication. Glucose oxidizing-fermenting and O/129 sensitive strains were dis tinguished on the basis of the following tests: sucrose and cellobiose util ization, sulphatase activity and polymyxin B resistance performed, respecti vely, on TCBS, CPC and SPS media. Responses to the presence of beta-galacto sidase, salt requirement and growth on triple sugar iron medium were also a dded. A total of 125 from 152 isolates were referred to the species Vibrio fluvialis (55 strains), V. alginolyticus (40), V. parahaemolyticus (11), V. vulnificus (10) and V. mimicus (9). The remaining 27 isolates were not ide ntified. The isolation of potentially pathogenic vibrios from cultivated mu ssels is a risk for health of people consuming raw seafood. Therefore, a lo ng-term monitoring programme should also include the search for these bacte rial species.