Detection of Escherichia coli O157:H7 using immunomagnetic separation and mPCR in Turkish foods of animal origin

The present study was conducted to investigate the presence of Escherichia coli O157:H7 in food samples of animal origin and to detect its virulence genes by immunomagnetic separation technique and multiplex PCR (mPCR). A total of 500 samples (consisting of diced meat, minced meat, burger, raw cow's milk and raw cow's milk cheese) were analysed. Escherichia coli O157:H7 was detected in 5 (1%) of 500 analysed samples including two diced meat, one minced meat and two raw-milk cheese. None of the burger samples tested contained E. coli O157:H7. Three isolates obtained from minced and diced meat were found to carry stx1, stx2, hlyA and eaeA genes whereas two isolates from raw-milk cheese were found to harbour the stx1, eaeA and hlyA genes. The results of this study suggest that raw meat and raw-milk cheese tested could pose public health problems in consumers with regard to their virulence factors. -

Keywords: Escherichia coli O157:H7;foods of animal origin;immunomagnetic separation; mPCR ;virulence genes