Relationship between the numbers of escherichia coli and the prevalence of escherichia coli o157:H7 on hides of carcasses at a large beef packing plant

Abstract

Due to the expense of monitoring multiple serotypes of Escherichia coli at slaughter, a study was conducted at a beef abattoir in southern Alberta to determine relationships between E. coli and E. coli O157:H7 on hides. Swab samples were collected from carcasses immediately prior to hide removal over 8 weeks in summer (n = 591) and winter (n = 686). Detection of E. coli was highest in summer (P , 0.05), although detection of E. coli O157:H7 did not differ by season. Numbers of E. coli did not vary by season, but were affected by slaughter plant hygiene schedules. E. coli O157:H7 was more likely (P , 0.001) to be detected on hides of carcasses with the most E. coli (.3.5 log CFU/50 cm2). For E. coli ,3.5 log CFU/50 cm2, the likelihood of detecting E. coli O157:H7 did not differ. Consequently, for 83% of carcasses, there was no relationship between numbers of E. coli and detection of E. coli O157:H7 on hides. Copyright ©, International Association for Food Protection.