Abstract: This study aimed to establish a quantitative assay method to detect Vibrio vulnificus in aquatic products based on droplet digital polymerase chain reaction (ddPCR). A pair of primers and probe were designed targeting the single-copy gene met in V. vulnificus. The specificity, sensitivity and repeatability of this method were tested through comparison with real-time PCR. The results indicated that the developed ddPCR method had good specificity, sensitivity and repeatability. In pure cultures, the limit of quantitation (LOQ) and limit of detection (LOD) of this method were 323 and 61 copies/mL, respectively. In artificially contaminated oyster samples, the sensitivity was 1.13 × 102 copies/g. The quantitative result of ddPCR was about 1.4 times as high as the plate counting result and was more stable and accurate than real-time PCR. Therefore, ddPCR is a rapid, specific and sensitive method for quantitative detection of V. vulnificus.

Key words: droplet digital polymerase chain reaction, Vibrio vulnificus, real-time quantitative polymerase chain reaction