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Years and years of testing ahead for bacteria in beef that ‘don’t behave’

Years and years of testing ahead for bacteria in beef that ‘don’t behave’

Beef producers have become quite successful at detecting and preventing contamination of E. coli 0157:h7 in their raw beef products — that’s thanks to years of experience after the Shiga toxin-producing bacterial strain (STEC) was first declared as an adulterant in raw beef in 1994.

However, the USDA Food Safety and Inspection Service has now expanded the adulterant list to include six non-0157 strains (026, 045, 0103, 0111, 0121, and 0145). The new rule had producers and scientists at the Institute of Food Technologists Annual Meeting on Tuesday (June 26) warning that these bacteria “don’t behave” like you’d want them to.

“With 0157, we’ve had years and years of testing. We haven’t had those years of experience in the lab with these,” said food safety and public health professor Mindy Brashears of Texas Tech University.

The rule, in place as of June 4, was in response to an October 2009 citizen’s petition. According to research microbiologist Christopher Sommers, the petition came after recent outbreaks and a CDC study that showed that these “big six” accounted for more than 70 percent of non-0157 STEC infections from 1983 to 2002.

A couple of companies—Costco and Beef Products Inc. (BPI)—already have food safety systems in place for non-0157 STEC strains. Director of food safety and quality assurance at BPI, Craig Letch, said that the company developed a system using “robust sampling” (n=167) and has spent well “over a million dollars” in outsourcing 100 percent of the testing for non-0157 STEC strains.

Costco Wholesale’s program for testing for non-0157 STEC strains has been in place since June 2010, according to director of food safety and quality assurance Christine Summers. “Obviously, we don’t want to make any of our customers sick,” she said, noting that the company produces about 160 million pounds of ground beef annually. However, she added that there are problems with the rule. “There is a diversity of STECS. It would be beneficial to identify the virulence genes that cause human illness. Knowledge needs to be gathered.”

Despite challenges, Brashears told the Las Vegas gathering that she’s optimistic that the methodologies are sure to continue to improve as testing progresses and more baseline data is collected. Ultimately, she said, interventions pre- and post-harvest will be key to reducing STECs and protecting the beef supply.

Written by David Despain

CONTACT: Mindy Brashears, Professor, Department of Animal and Food Sciences, Texas Tech University at (806) 742-2805 ext. 235 or


Editor’s Note: The USDA Food Safety and Inspection Service has issued methodology for detecting the ‘big six’ at


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