Simultaneous, Quantitative Detection of Four Common Vibrio Species by Microfluidic Chamber-Based Digital PCR in...

Vibrio spp., known as typical marine pathogens, pose serious threats to human health worldwide due to their high incidence and prevalence. In this study, a quantitative detection method was developed for Vibrio parahaemolyticus, Vibrio vulnificus, Vibrio cholerae and Vibrio alginolyticus in aquatic products. A set of multiplex chamber-based digital PCR (cdPCR) primers and probes was designed based on new molecular targets of Vibrio species. The conditions of multiplex cdPCR were optimized and compared with those of multiplex qPCR. Under optimal conditions, the performance indicators, including the specificity, linear range, and detection limit, were systematically evaluated. The results indicate that the established method had 100% specificity among all tested strains and did not cross-react with other foodborne pathogens tested in parallel. The linear dynamic range was 10²-10⁶ CFU/mL, and the limits of detection (LODs) for V. parahaemolyticus, V. vulnificus, V. cholerae and V. alginolyticus were 5.40 × 10² CFU/mL, 3.05 × 10² CFU/mL, 4.55 × 10² CFU/mL and 1.32 × 10² CFU/mL, respectively. Furthermore, the feasibility of the proposed method was assessed in contaminated food samples, with a 10-fold improvement in detection sensitivity over that of the qPCR method under the conditions of this study. The entire detection process could be completed within 2 h. Taken together, the results of this study offer a readily adaptable diagnostic method, allowing for the simultaneous and quantitative detection of four pathogenic Vibrio species, which is promising for food safety and environmental monitoring.