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United States Department of Agriculture

Agricultural Research Service

Title: Detection and Quantitation of Enterohemorrhagic Escherichia Coli O157, O111, and 026 in Beef and Bovine Feces by Real-Time Polymerase Chain Reaction

Author
item Sharma, Vijay

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 19, 2002
Publication Date: September 20, 2002

Interpretive Summary: Escherichia coli O157:H7, a Shiga toxin-producing E. coli (STEC), is by far the most prevalent in human disease and has been associated with the most important foodborne outbreaks in the USA and Canada. However, E. coli O26 and O111, which are also STEC, have emerged as significant causes of human disease over the past 20 years. Estimates indicate that E. coli O26 and O111 may be responsible for 25% of all cases with serious disease symptoms such as kidney failure and risk of death. Most human E. coli O157:H7, O26, and O111 infections are caused by consumption of contaminated foods (ground beef, milk, and produce) and water. Cattle are generally considered the major reservoir for these disease-causing bacteria. E. coli O157:H7, O26, and O111 colonize intestine of cattle and are secreted into feces of these animals. These bacteria can survive in feces for months and are the major source for the transmission of these bacteria to other cattle and humans. The objective of this study was to develop real-time PCR (R-PCR) methods for rapid detection and quantitation of O157, O26, and O111 in cattle feces and ground beef. We developed two sets of specific and sensitive R-PCR assays for detecting low levels (1 to 10 bacterial cells) of these bacteria in feces and beef. The meat processing industry, which slaughters more than $50 billion worth of livestock annually, could use this technology to meet current federal regulations that mandate zero tolerance for visible fecal contamination for E. coli O157:H7. Moreover, these methods will serve as valuable techniques to monitor the transmission and persistence of these bacteria in cattle and for testing produce and water for fecal contamination.

Technical Abstract: Escherichia coli O157:H7, a Shiga toxin-producing E. coli (STEC), is by far the most prevalent in human disease and has been associated with the most important foodborne outbreaks in the USA and Canada. However, E. coli O26 and O111, which are also STEC, have emerged as significant causes of human disease over the past 20 years. Estimates indicate that E. coli O26 and O111 may be responsible for 25% of all cases with serious disease symptoms such as kidney failure and risk of death. Most human E. coli O157:H7, O26, and O111 infections are caused by consumption of contaminated foods (ground beef, milk, and produce) and water. Cattle are generally considered the major reservoir for these disease-causing bacteria. E. coli O157:H7, O26, and O111 colonize intestine of cattle and are secreted into feces of these animals. These bacteria can survive in feces for months and are the major source for the transmission of these bacteria to other cattle and humans. The objective of this study was to develop real-time PCR (R-PCR) methods for rapid detection and quantitation of O157, O26, and O111 in cattle feces and ground beef. We developed two sets of specific and sensitive R-PCR assays for detecting low levels (1 to 10 bacterial cells) of these bacteria in feces and beef. The meat processing industry, which slaughters more than $50 billion worth of livestock annually, could use this technology to meet current federal regulations that mandate zero tolerance for visible fecal contamination for E. coli O157:H7. Moreover, these methods will serve as valuable techniques to monitor the transmission and persistence of these bacteria in cattle and for testing produce and water for fecal contamination.

Last Modified: 7/31/2014
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