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, and O111) and four virulence genes (stx1, stx2, eaeA, and ehxA). Overall, 1145 fecal pools were evaluated, with 506 (44.2%) being positive for one or more of the E. coli O-serogroups. The pool prevalences for E. coli O157, O45, O26, O103, O121, O145, and O111 were 19.7%, 13.8%, 9.9%, 9.3%, 5.5%, 1.1%, and 0.5%, respectively. Nearly all pools were positive for ehxA (99.7%) or stx2 (98.6%). The pool level prevalence for stx1 and eae was 65.5% and 69.3%, respectively. Pools that were positive for one or more of the other E. coli O-serogroups were 1.37 times more likely to be positive for E. coli O157. Conversely, pools that were positive for E. coli O157 were 1.43 times more likely to be positive for at least one of the other E. coli O-serogroups evaluated. These data will be useful to understand the expected prevalence of potential Shiga toxin-producing E. coli in cattle feedlots.

Summer and Winter Prevalence of Shiga Toxin–Producing Escherichia coli (STEC) O26, O45, O103, O111, O121, O145, and O157 in Feces of Feedlot Cattle

“…Although a few studies have addressed the detection of non-O157 STEC in cattle feces, data regarding the frequency of non-O157 STEC serogroups in preharvest cattle in the Unites States are still limited (Cernicchiaro et al, 2013;Dargatz et al, 2013;Baltasar et al, 2014;Ekiri et al, 2014). The prevalence of non-O157 STEC organisms obtained in our study was lower than what has been reported in previous studies (Barkocy-Gallagher et al, 2003;Cernicchiaro et al, 2013;Ekiri et al, 2014) but comparable to others (Cobbold et al, 2004).…”

“…Non-O157 serogroup and STEC fecal prevalence estimates reported in cattle range from 0.0 to 90.7% and 0.9 to 16.9%, respectively, in the United States Cernicchiaro et al, 2013;Dargatz et al, 2013;Baltasar et al, 2014;Ekiri et al, 2014). However, only a few studies have assessed seasonality of non-O157 STEC shedding in cattle (Barkocy-Gallagher et al, 2003;Alexa et al, 2011;Tanaro et al, 2012).…”

Update on non-O157 Shiga toxin-producing E. coli as a foodborne pathogen: analysis and control

“…The STEC strains consisted of 24 serotypes and included O103:H2 ( n = 12), O136:H12 ( n = 8), O178:H19 ( n = 8), and O103:NM ( n = 5) (Tanaro et al ., 2012 ). Fecal samples obtained from beef cattle in 21 feedlots from four US states were tested by PCR for seven STEC serogroups (Dargatz et al ., 2013 ). All of the feedlots (100%) were positive for O157 and O45, 90.5% for O26, 85.7% for O103, 76.2% for O121, 33.3% for O145, and 19.1% were positive for O111.…”

“…All of the feedlots (100%) were positive for O157 and O45, 90.5% for O26, 85.7% for O103, 76.2% for O121, 33.3% for O145, and 19.1% were positive for O111. All of the feedlots were positive for one or more of the serogroups (Dargatz et al ., 2013 ).…”

Effect Of Source In Online Video Training For Cattle Producers

“…As a result of the public health issues and the economic impact on the beef industry, the beef industry has adopted procedures to reduce the occurrence of E. coli O157:H7 in meat processing facilities (Dargatz et al, 2013). In addition, the use of preharvest E. coli management strategies has been recognized as an important part of a safe beef products system (USDA, 2014b).…”