Effects of sublethal heat, bile and organic acid treatments on the tolerance of Vibrio parahaemolyticus to lethal low-salinity

As a marine foodborne pathogenic bacterium commonly found in seawater and seafood, Vibrio parahamolyticus often encounters low salinity stress when the contaminated seafood is washed with fresh water during food processing. This study investigated the influence of prior adaptation to sublethal stresses on the tolerance of Vibrio parahaemolyticus ST550 to lethal low salinity. Results revealed that tolerance to lethal low salinity (0.25% NaCl) was enhanced in the exponential phase cells by prior adaptation in sublethal bile (0.05%), heat (41 °C), acetic (0.05%) or lactic acid (1.0%), but not in low acidity (pH4.48). In stationary phase cells, tolerance to lethal low salinity was enhanced by prior adaptation in bile and heat. Among the stresses examined, bile was the most efficient one to induce tolerance to lethal low salinity in this pathogen.