Verocytotoxigenic Escherichia coli O157 in beef and sheep abattoirs in Ireland and characterisation of isolates by Pulsed-Field Gel Electrophoresis and Multi-Locus Variable Number of Tandem Repeat Analysis

►VTEC O157 was isolated from 7.6% and 3.9% of bovine rectal and carcass swab samples and from 5.8% and 2.9% of ovine rectal and carcass swab samples respectively. ►None of the bovine minced meat samples (n = 77) and only one of the 14 ovine minced meat samples was positive for VTEC O157. ►Results showed that cattle and sheep presented for slaughter in Ireland harbour VTEC O157, and although the levels entering the food chain are low, this should not be overlooked as possible sources of zoonotic infection. ►Following PFGE and MLVA, cross contamination from faeces to carcasses was identified. ►MLVA discriminated better than PFGE in addition to being more rapid and less labour intensive.