Factors affecting the growth and survival of Vibrio parahaemolyticus isolated from oyster

Abstract

This study was performed to identify the effect of temperature, NaCl concentration and ultraviolet ray on the growth and survival of Vibrio parahaemolyticus isolated from oyster. Two V. parahaemolyticus isolates were incubated in APW at 40C, 270C, 370C, 420C, 470C; under ultraviolet light; and incubated in APW with 2%, 6%, and 10% NaCl. The number of V. parahaemolyticus at different conditions was determined over time. Drop planting method was used for V. parahaemolyticus quantitative. The studied results showed that the optimum temperature and NaCl concentration for the growth of two V. parahaemolyticus isolates were 370C and 2% NaCl, respectively. At temperature of 270C and 420C, or at 6% NaCl, V. parahaemolyticus were able to growth but less than at 370C and 2% NaCl. At 40C, both V. parahaemolyticus isolates were not able to multiply, only maintaining stable numbers. Meanwhile, at 470C, 10% NaCl concentration, or under influence of ultraviolet light, V. parahaemolyticus were unable to growth with decreasing numbers over time.