Application of the VPp1 bacteriophage combined with a coupled enzyme system in the rapid detection of Vibrio parahaemolyticus

Abstract

For rapid and quantitative detection of Vibrio parahaemolyticus, a method combining the specific lysis of bacteriophages with a bacterial luciferase–flavin mononucleotide:nicotinamide adenine dinucleotide oxidoreductase bioluminescent system in vitro was developed. A V. parahaemolyticus detection system was established by optimizing three main influencing factors: bacteriophage titer, volume ratio of the bacteriophage to its host bacterium, and lysis time. A standard curve between the number of bacteria and the luminescence intensity of the coupled enzyme system was studied and revealed a good linear relationship. More than 107colony-forming units (cfu)·ml−1 bacteria in pure culture and >108cfu·ml−1 bacteria in oyster samples were readily detected without pre-enrichment. Furthermore, >100cfu·ml−1 bacteria in oyster samples were readily detected after 4h of enrichment culture. Because of its rapid detection, high specificity, and simplicity in operation, this method is an effective tool for detecting living bacteria in food and environmental samples.