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United States Department of Agriculture

Agricultural Research Service


Location: Meat Safety & Quality Research

Title: Distribution of Shiga-Toxigenic Escherichia coli O157 in the Gastrointestinal Tract of Naturally O157-Shedding Cattle at Necropsy

item Keen, James -
item Laegreid, William -
item Chitko Mckown, Carol
item Durso, Lisa
item Bono, James

Submitted to: Applied and Environmental Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 30, 2010
Publication Date: August 1, 2010
Repository URL:
Citation: Keen, J.E., Laegreid, W.W., Chitko Mckown, C.G., Durso, L.M., Bono, J.L. 2010. Distribution of Shiga-Toxigenic Escherichia coli O157 in the Gastrointestinal Tract of Naturally O157-Shedding Cattle at Necropsy. Applied and Environmental Microbiology. 76(15):5278-5281.

Interpretive Summary: Escherichia coli O157:H7 is an important foodborne pathogen. Cattle are considered a reservoir for this bacterium. It is common, to test cattle feces to determine if any individual animal is shedding E. coli O157:H7; however, more information about where in the cattle gastrointestinal tract E. coli O157:H7 can be found is needed to develop interventions. In animals that were fecal shedding E. coli O157:H7, we found E. coli O157:H7 in samples from the mouth, pharynx, tonsils, lymph nodes, esophagus, all four sections of the stomach, and the small and large intestines, though the specific location of E. coli O157:H7 positive cultures varied between animals. In a larger number of animals presented for harvest, we found E. coli O157:H7 at multiple locations throughout the small and large intestines. Although 31% of the animals were culture positive for E. coli O157:H7 somewhere along the intestinal tract, only 26% of those were fecal-culture positive. These data suggest that fecal shedding underestimated E. coli O157:H7 prevalence in the beef cattle gut and identified potential intervention sites.

Technical Abstract: Shiga-toxigenic Escherichia coli O157 (STEC O157) occurrence was determined along the entire gastrointestinal tract (GIT) of four naturally-infected cattle and at specific locations for 61 additional animals. STECO157 was recovered along the entire length of the GIT, though inter-animal distribution was variable. Fecal shedding underestimated STECO157 prevalence in the gut.

Last Modified: 10/1/2014
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