Superficial contamination of bovine carcasses by Escherichia coli O157 : H7 in a slaughterhouse in Normandy (France)

In 1997, analyses were carried out on 255 bovine carcasses to determine the extent of superficial contamination by E. coli O157. A 50-cm(2) meat sampl e taken from all carcasses was collected and tested using immunomagnetic se paration method to detect E. coli O157. One strain of E. coli O157 bacteriu m was isolated and sent to the reference national center (Institut Pasteur, Paris). The strain was confirmed as E. coli O157:H7 and found to contain t wo out of the three pathogenicity genes (eae and EHEC-hlyA) necessary for e nteropathogenicity. Shiga toxin genes were not detected. Superficial contam ination of E. coli O157:H7 was established, but at low level (0.4%). (C) 20 01 Elsevier Science Ltd. All rights reserved.