Prevalence of Shiga toxin–producing Escherichia coli and associated virulence genes in feces of commercial feedlot cattle

K-REx Repository

Show simple item record Cernicchiaro, Natalia Cull, Charley A. Paddock, Zachary Dean Shi, Xiaorong Bai, Jianfa Nagaraja, Tiruvoor G. Renter, David G. 2013-10-28T20:37:09Z 2013-10-28T20:37:09Z 2013-09-25
dc.description.abstract The objective of this study was to determine the prevalence of Shiga toxin–producing Escherichia coli (STEC) serogroups and associated virulence genes in feces of commercial feedlot cattle. During March to May 2011, fecal samples were collected from individual cattle (n=960) in 10 cohorts (cattle subpopulations within a feedlot) comprising 17,148 total steers that originated from 48 backgrounding operations in six U.S. states. Fecal samples were enriched in E. coli broth and subjected to two detection protocols: (1) an 11-gene multiplex polymerase chain reaction (PCR) that identifies seven O serogroups (O26, O45, O103, O111, O121, O145, and O157) and four virulence genes (stx1, stx2, eae, and ehxA) applied to extracted total DNA (“direct PCR”); and (2) cultural procedures that involve immunomagnetic separation (IMS) with O26, O103, and O111 beads, plating on a nondifferential MacConkey agar, followed by the multiplex PCR of pooled colonies (“culture-based method”). Generalized linear mixed models were used to adjust prevalence estimates for clustering. Based on direct PCR detection, O157 (49.9%) was the most prevalent O serogroup followed by O26 (20.3%), O103 (11.8%), O121 (10.7%), O45 (10.4%), O145 (2.8%), and O111 (0.8%). Cumulative adjusted prevalence estimates were 22.3, 24.6, and 0.01% for O26, O103, and O111 serogroups, respectively, based on culture-based methods. However, prevalence varied significantly by cohort (p-values<0.05) for O26, O121, and O157 based on direct PCR, and for O26, O103, and O111 serogroups based on culture-based methods. Results of this study indicate that all seven STEC serogroups were identified in feedlot cattle feces, with O157, O26, and O103 being the most prevalent serogroups. A substantial proportion of serogroup-positive samples did not harbor Shiga toxin genes; thus, additional elucidation of the potential human health risk is required. Further evaluation of diagnostic methods for non-O157 STEC is needed given their impact on prevalence estimation. en_US
dc.language.iso en_US en_US
dc.relation.uri en_US
dc.rights This is a copy of an article published in Foodborne Pathogens and Disease © 2013 Mary Ann Liebert, Inc.; Foodborne Pathogens and Disease is available online at: en_US
dc.subject Escherichia coli en_US
dc.subject Shiga toxin en_US
dc.subject Feces en_US
dc.subject Cattle en_US
dc.subject Feedlot en_US
dc.title Prevalence of Shiga toxin–producing Escherichia coli and associated virulence genes in feces of commercial feedlot cattle en_US
dc.type Article (publisher version) en_US 2013 en_US
dc.citation.doi 10.1089/fpd.2013.1526 en_US
dc.citation.epage 841 en_US
dc.citation.issue 10 en_US
dc.citation.jtitle Foodborne Pathogens and Disease en_US
dc.citation.spage 835 en_US
dc.citation.volume 10 en_US
dc.contributor.authoreid ncernic en_US
dc.contributor.authoreid xshi en_US
dc.contributor.authoreid jbai en_US
dc.contributor.authoreid tnagaraj en_US
dc.contributor.authoreid drenter en_US

Files in this item

This item appears in the following Collection(s)

Show simple item record

Search K-REx

Advanced Search


My Account


Center for the

Advancement of Digital