Incidence and level of Vibrio parahaemolyticus associated with freshwater plankton.

We isolated Vibrio parahaemolyticus from plankton samples collected from different freshwater areas in the vicinity of Calcutta, India. Levels of this organism in association with freshwater plankton were low (less than 90 organisms per g). All of the 16 strains of V. parahaemolyticus isolated in this study were Kanagawa negative, and all except 1 were untypable. The occurrence of V. parahaemolyticus in association with freshwater plankton suggests that adsorption onto plankton may aid the survival of this moderately halophilic organism in freshwater milieus.