Occurrence of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella and Campylobacter spp. on beef carcasses in Northern Ireland.

A survey of beef carcasses was conducted in all 10 European community approved abattoirs in Northern Ireland to determine the incidence of Escherichia coli O157:H7. Analyses were based on excised samples of neck meat taken less than 48 h post-kill. Overall, 780 carcasses were sampled and all were negative for E.

Benefits of indirect impediometry, using Rappaport-Vassiliadis broth, for the detection of Salmonella in processed animal protein.

Four hundred samples of processed animal protein were analysed for the presence of Salmonella using two impediometric methods. The direct method using both Easter and Gibson's, and Ogden's media, as defined in legislation applying throughout the UK, was less selective and sensitive, detecting 30% fewer positive samples than the indirect method using Rappaport-Vassiliadis broth. The indirect method detected 63 positive samples with a false positive rate of less than 10% and about 87% of positive samples were detected less than 12 h after being loaded onto the impedance equipment.