Survival of Normal and Chlorine-Stressed Pathogenic and Non-Pathogenic Vibrio parahaemolyticus Under Adverse Conditions

Background: vibrio parahaemolyticus is an important human pathogen which can cause gastroenteritis when consumed in raw or partially-cooked seafood. the pathogenesis of v. parahaemolyticus is based on the presence of virulence factors: the thermostable direct hemolysin (tdh) and tdh-related hemolysin (trh), encoded by the tdh and trh genes, respectively.objectives: the present study aimed to evaluate the survival of normal and chlorine-stressed cells of pathogenic and non-pathogenic v. parahaemolyticus under adverse conditions.materials and methods: normal and chlorine-stressed cells of pathogenic and non-pathogenic v. parahaemolyticus were subjected to environmental stresses such as low storage temperature (4 and -18°c), high incubation temperature (50°c) and high nacl content (20%). viable counts were then made at various time intervals by surface plating on tsa-2.0% nacl, and the survival rates of the cells were determined and compared.results: findings of the current study revealed that the normal cells of pathogenic and non-pathogenic v. parahaemolyticus, as well as the chlorine-stressed cells of both strains behave similarly under adverse conditions. in addition, chlorine stress increased the susceptibility of pathogenic and non-pathogenic v. parahaemolyticus to incubation at 4°c, and the presence of high nacl content in the medium. however, chlorine stress did not significantly affect the thermal tolerance of pathogenic and non-pathogenic v. parahaemolyticus, and the susceptibility to incubation at -18°c.conclusions: chlorine-stressed cells of v. parahaemolyticus were more susceptible to adverse conditions than the non-stressed ones. pathogenic and non-pathogenic strains showed the same survival characteristics under the adverse conditions. these results should be considered in the development of food preservation measures.