Acid Adapted Vibrio parahaemolyticus and Vibrio vulnificus Enhance Survival in Acidic Environments

Abstract

Prior exposure of Vibrio parahaemolyticus and V. vulnificus cells to pH 5.5 resulted in an adaptive acid tolerance response of these bacteria to pH 4.0. Acid adapted V. parahaemolyticus and V. vulnificus cells at pH 5.5 for 1 h were reduced by 5 logs within 2 h after exposure to pH 4.0, while non-acid adapted cells were reduced by 4.5 logs within 15 to 30 min after exposure to pH 4.0. Chloramphenicol treated cells were not acid tolerant and were reduced by more than 5 logs within 10 min after exposure to pH 4.0 conditions. This study suggests that development of acid tolerance in V. parahaemolyticus and V. vulnificus may increase the likelihood of these bacteria to survive the acid environment found in the human stomach.