Abstract: This study aimed to establish a new accurate quantitative method to detect Staphylococcus aureus in yogurt using droplet digital PCR (ddPCR). Specific primers and probes targeting the nuc gene of Staphylococcus aureus were designed, and the PCR reaction system was optimized. The specificity and sensitivity of ddPCR for detecting the target gene were tested using the DNA extracted viable bacterial cells, and the quantitative results were analyzed. The ddPCR method could be useful to quantitatively detect S. aureus in yogurt with good specificity. The limit of detection (LOD) of the method was 3.3 × 101 CFU/g, and the quantitative deviation was +10.18%, which proved the feasibility of using ddPCR for absolute quantitation of S. aureus. It will provide a useful demonstration for standardized control systems of other food-contaminating bacteria and foodborne pathogenic bacteria.

Key words: droplet digital PCR, yogurt, detection, Staphylococcus aureus