Effects of E. Coli O157H7 Vaccination on the Prevalence and Load of E. Coli O157H7 and Non-O157 STEC on the Hides of Beef Cattle at Harvest

<p>Escherichia coli O157:H7 remains the major foodborne pathogen of concern for the beef industry. Extensive research has been conducted and is on-going to identify and develop novel intervention strategies to reduce E. coli O157:H7 from live cattle and processed carcasses. Recent work has shown that hides are the main source of beef carcass contamination at slaughter and as such reductions in the prevalence of E. coli O157:H7 on the hide are directly related to lower carcass prevalence rates. Interventions applied to cattle during production have been designed to reduce hide contamination indirectly through lowering the prevalence and levels of E. coli O157:H7 shed in the feces of cattle.</p>
<p>Emerging technologies to reduce the prevalence of E. coli O157:H7 from cattle before arrival at a harvest facility have proven promising in small scale feedlot studies. The present study evaluated the efficacy of the Epitopix SRP E. coli O157:H7 vaccine under large scale commercial conditions. The vaccinated cattle were compared to cattle slaughter during the same timeframe from feedlots in the same general region. While E. coli O157:H7 was the main target of the vaccine and the main focus of this work, we also analyzed a subset of samples for vaccine effects on non-O157 Shiga toxin-producing E. coli (STEC). Also, isolates were analyzed for tracking purposes to determine the contribution to hide contamination made by the lairage environment (defined as processing plant holding pen area).</p>