Abstract

Vibrio parahaemolyticus is an estuarine bacterium widely distributed in natural aquatic environments and also a well-known food-borne pathogen, and like other enteropathogenic bacteria, it survives both in its natural environment and in its host. The transition from one state to another requires a high capacity to adapt to different physico-chemical parameters, process which increases the synthesis of specific proteins, including heat-shock proteins (HSPs). In order to investigate the immunogenicity of heat shock proteins from different cellular fractions of V. parahaemolyticus grown under sub-lethal heat and osmotic shock, we analyzed the response of holoxenic mice to V. parahaemolyticuscellular fractions injected intraperitoneally by examining the anti-HSP antibodies response to stressful conditions and the immune protection installed after several immunizations. The supernatant and total cellular extract of heat or simultaneously heat and osmotically-stressed bacterial cultures induced the early occurrence of anti-HSP antibodies (after 4 immunizations), while after 8 immunizations, the anti-HSP antibodies were present in the majority of the tested batches, the most immunogenic fraction proving to be the heat-stressed culture supernatants.

Key words: Vibrio parahaemolyticus, heat shock proteins, heat shock response, mice immunization.