ABSTRACT
We established a multiplex direct PCR for rapid detection of E.coli,Salmonella,Staphylococcus aureus,Listeria and Yersinia enterocolitica bacteria.Multiplex direct PCR primers were designed according to gene sequences of phoA (E.coli),inv A (Salmonella),nuc (S.aureus),hl y (Listeria),and ail (Y.enterocolitica).After the multiplex direct PCR were established,the specificity and sensitivity of primers were detected.Then,multiplex direct PCR was applied to examine 60 swine product samples,the detection specificity,accuracy and positive predictive value were calculated compared with the gold standard culture method.Results showed that multiplex direct PCR primers could be used for specific detection of E.coli,Salmonella,S.aureus,Listeria and Y.enterocolitica,with the minimal detectable limit of 10,1,100,1 and 1 CFU,respectively.For the examination of 60 swine product samples using multiplex direct PCR,15 were positive for E.coli,6 positive for Salmonella,21 positive for S.aureus,20 positive for Listeria,and 35 positive for Y.enterocolitica,with all positive detection rates higher than that of culture.The total detection sensitivity was 100％,accuracy was 94％,and positive predictive value was 81.44％.Multiplex direct PCR could be used for specific and sensitive detection of common food-borne pathogens,and the testing time was shorten to be 3 hours because of saving time for template extraction.Multiplex direct PCR might serve the detection of food-borne pathogens in food safety risk monitoring much better.