Abstract:

To establish a multiplex PCR method for the simultaneous detection of pathogens (Staphylococcus aureus, Salmonella spp, and Shigella flexneri) in soybean products, FTA filter was used to directly extract the template DNAs from soybean products. On the basis of nuc gene of Staphylococcus aureus, phoP gene of Salmonella spp, ipaH gene of Shigella flexneri, three pairs of specific primers were designed for the multiplex PCR detection, and the reaction conditions were optimized. The results showed that three targeted genes of 280, 409, and 326 bp could be specifically amplified using the three pairs of primers. Without bacterial enrichment, the sensitivities of the multiplex PCR for detecting Staphylococcus aureus, Salmonella spp, and Shigella flexneri were 101, 101, and 102 CFU/ml, respectively, and the detection could be finished within 4 h. This multiplex PCR method is accurate, fast and effective, thereby providing a new approach for the detection of Staphylococcus aureus, Salmonella spp, and Shigella flexneri in soybean products.

Key words: multiplex PCR, food-borne pathogen, detection, FTA filter