[Primarily study on a multiplex PCR-based system for the rapid detection of Salmonella spp., Shigella spp. and Escherichia coli O157:H7].

OBJECTIVE: To establish a multiplex PCR-based system for the simultaneous detection of Salmonella spp., Shigella spp. and Escherichia coli 0157:H7 in 12 hours. METHODS: After 6 h nonselective enrichment in BPW, DNA template were prepared at 100 degrees C for 10 min. Three sets of primers were designed to amplify the gene segments of invA of Salmonella spp, ipaH of Shigella spp, and uidA of E. coli 0157:H7, and the products were analyzed by electrophoresis. At the same time, this system was optimized, and the specificity and sensitivity of this system were evaluated. RESULTS: Three target bacteria were detected in 12 h by using this multiplex PCR-based system. The sensitivity of it was up to 10-30 cfu/ml, and the high specificity was demonstrated by detecting 23 target stains and 15 non-target stains. CONCLUSION: A rapid, specific, and sensitive multiplex PCR-based system for the simultaneous detection of Salmonella spp., Shigella spp. and E. coli 0157:H7 in 12 h has been studied primarily.