[Multiplex PCR assay against E. coli O157 in foodstuffs]

A multiplex PCR assay for detection of Escherichia coli O157:H7 was developed with 4 pairs primers which focus on its specific fliC, rfbE, SLT I and SLT II genes. The target genes fragments of the PCR assay were 560 bp, 678 bp, 210 bp and 484 bp. The multiplex PCR had very high specificity to match all the 71 tested strains including 58 E. coli strains and other 18 strains. The strain of E. coli O157:H7 was identified in one step, and the type of SLT was also identified as well. With the enrichment procedure, the strain of E. coli O157:H7 were recovered at the detection limit of 0.1 cfu/ml from artificial inoculated pasteurized milk.