Prevalence of Escherichia coli O-Types and Shiga Toxin Genes in Fecal Samples from Feedlot Cattle

Abstract While efforts to control foodborne illness associated with the Shiga toxin–producing Escherichia coli (E. coli) O157 through processes and procedures implemented at harvest facilities have been very successful, there is concern about the burden of illness associated with other Shiga toxin–producing E. coli. The U.S. Department of Agriculture Food Safety and Inspection Service announced plans to classify an additional six non-O157 Shiga toxin–producing E. coli as adulterants. Little is known about the prevalence and distribution of these E. coli in the animal production environment. An investigation of the prevalence of O157 and the six major non-O157 E. coli serogroups was conducted in 21 feedlots over the period July 2011 to October 2011. Individual fecal swabs were collected from cattle approximately 60 days after their arrival in the feedlot and were pooled for evaluation using a polymerase chain reaction assay to identify the presence of seven E. coli O-types (O157, O45, O103, O121, O145, O26...