Survival of Vibrio parahaemolyticus in Presence of Chlorine

Vibrio parahaemolyticus is well recognised as the causative agent of gastroenteritis associated with seafood consumption. The concentration and contact time required by the commonly used sanitizer, hypochlorite for killing/ reducing the cells of V. parahaemolyticus in phosphate buffered saline (PBS) and in association with fish was studied. A minimum level of 0.5 ppm of available chlorine was able to reduce the count of both Kanagawa positive (K+) and Kanagawa negative (K-) V.parahaemolyticus in PBS by 90% within 5 min and complete killing of both was achieved in 20 and 30 min, respectively. In fish artificially contaminated with K + V.parahaemolyticus and exposed to 10 and 20 ppm available chlorine, complete destruction of the cells was observed in 10 min, but at 30 ppm level, the time required was only 5 min. Hemolytic activity of the K + V.parhaemolyticus was not affected by chlorine treatment.