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United States Department of Agriculture

Agricultural Research Service

Research Project: MOLECULAR CHARACTERIZATION OF PATHOGENS AND THEIR RESPONSES TO ENVIRONMENTAL FACTORS

Location: Molecular Characterization of Foodborne Pathogens

Title: Non-O157 Shiga Toxin-Producing E. coli Associated with Muscle Foods

Author
item Fratamico, Pina

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 7, 2007
Publication Date: July 28, 2007
Citation: Fratamico, P.M. 2007. Non-O157 Shiga Toxin-Producing E. coli Associated with Muscle Foods. Meeting Abstract. P.195.02.

Technical Abstract: Escherichia coli strains that produce Shiga toxins, referred to as Shiga toxin-producing E. coli (STEC) or verotoxigenic E. coli (VTEC), cause hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS). E. coli O157:H7 is the most common cause of STEC infection; however, numerous non-O157 STECs belonging to serogroups O26, O103, O111, O121, O145, and others have been associated with outbreaks and cases of HC and HUS. In some countries non-O157 STEC are isolated more frequently from clinical cases than E. coli O157. Cattle and other ruminants are important reservoirs for these pathogens, and foods of animal origin or food and water contaminated with animal feces have been associated with STEC infections. A study conducted as part of the National Animal Health Monitoring System's Swine 2000 program, which examined 687 fecal samples, showed that swine are a reservoir of STEC strains that can potentially cause human illness. Detection of non-O157 STEC is problematic because these strains are indistinguishable from other E. coli when employing conventional culture-based methods. Thus, little is known on the incidence of non-O157 STEC in food, and the prevalence of non-O157 STEC in the population is presumably grossly underestimated. Methods based on the PCR targeting genes within the O antigen gene cluster of different STEC serogroups and STEC virulence genes were developed for identification and detection of these pathogens. Additional research is needed to identify and characterize emerging pathogenic non-O157 STECs, identify animal reservoirs, and develop methods for detection of these pathogens, which will allow for surveillance of STEC in food, animals, and the environment and an assessment of their importance in human infections.

Last Modified: 8/19/2014