Increased public health surveillance and enhanced pathogen subtyping methodologies have implicated cattle and beef products as possible novel sources of Shiga toxin-producing Escherichia coli (STEC) other than serogroup O157 (non-O157 STEC), Clostridium difficile, and Campylobacter jejuni. The objectives of this study were to determine the prevalence of these pathogens in live cattle at the time of slaughter and to ascertain if there were any differences in prevalence between cull cattle and fattened beef cattle.
Findings: Nine hundred and forty-four fecal samples were collected from cattle presented for slaughter at four distinct geographic regions in the US. Beef cattle were 1.8 times more likely to carry campylobacter in their feces than cull cattle (43% vs. 28%). The prevalence of E. coli O157, O26, and STEC was similar in both groups of cattle, at 7.3%, 7.4%, and 54% respectively. Clostridium difficile was recovered from only 10 of the specimens (1%), all of which were of cull cattle-origin. Since not all strains of these bacteria have been shown to be a threat to food safety, additional molecular tests are required to determine if these organisms present in the feces of live animals pose a potential reservoir for beef contamination and public health. When compared to the low prevalence STEC and Campylobacter isolation rates from ground beef, these data indicate that contamination of carcasses during slaughter is an infrequent event. Outbreak investigations of these emerging pathogens should continue to explore a variety of novel potential sources including such things as vegetables and peanut butter.