Study On The Method Of Detecting Foodborne Pathogens By Liquid - Phase Gene Chip

One pairs of specific oligonucleotide primers and probes were designed according to the 23s rDNA gene of Staphylococcus aureus, the iap gene of Listeria monocytogenes, and the ipaH gene of Shigella spp., respectively to establish a method for diagnosing three foodborne pathogenic bacteria simultaneously by liquid gene chips. The multiple PCR reaction system were established and optimized, acquiring the target fragment with the sizes of 246bp,112bp,174bp, which have 97%,98% and 95% identities for Staphylococcus aureus, Shigella spp., and Listeria monocytogenes, respectively, as compared with those published. The optimized hybridization condition between the target segment and the coupled microspheres were 54℃for 25min. The products were detected in a Luminex 100 suspension array system. The detecting sensitivity of Staphylococcus aureus, Listeria monocytogenes and Shigella spp. were 38 CFU/ml, 44CFU/ml and 21 CFU/ml, respectively. The corresponding detecting sensitivities in PCR systems were 380 CFU/ml,470 CFU/ml, and 240 CFU/ml which were 10 times less sensitive than those in liquid-gene-chip system. Based on the results above, this study established initially the liquid-gene-chip method for detecting the food-borne pathogens. We here report a more efficient and reliable method for foodborne pathogenic bacteria, which will have a good prospect.