Texas researchers give E.coli STEC project update

By Joseph James Whitworth

- Last updated on GMT

Shiga Toxin-Producing E. coli is an issue in beef safety
Shiga Toxin-Producing E. coli is an issue in beef safety

Related tags Bacteria Stec

Texas researchers have presented their latest work on Shiga-toxin producing E. coli (STEC) at a conference dedicated to tackling the issue.

The Texas A&M AgriLife Research and the department of animal science at Texas A&M University gave an update at the event in Lincoln, Nebraska.

Their part focusses on developing interventions to lessen STEC risk and compare their feasibility for large, small and very small beef producers.

Validate process controls

Dr Gary Acuff, director of the Texas A&M Center for Food Safety in College Station, and one of the research team members, presented at the conference.

“We are looking at ways to validate process controls, using surrogate organisms in the plant. The advantages of using surrogates are they are non-pathogenic and we have the data as they respond in the same way,” ​he told FoodQualityNews.com.

“Industry often uses hot water spray and lactic acid spray at the moment.

“A major challenge is understanding the organism, the data is sometimes unpredictable from when it is present in the animal and the more information we have about the bacteria the better the chances are of control.”

Progress of the work

Two graduate students in the Texas A&M department of animal science are investigating novel methods of beef safety preservation.

Carolina Gonzalez, a master’s student,​ is looking at the use of fermentative microorganisms to produce natural antimicrobial compounds on beef top sirloins to inhibit the growth of STEC.

Her research demonstrates the production of lactic acid by these organisms on beef surfaces during product aging.

This will help beef industry members understand how non-pathogenic microorganisms can inhibit the growth of pathogenic microbes on large cuts of beef prior to preparation.

Tamra Tolen, a Ph.d. student, is exploring the ability of differing plant-derived antimicrobial essential oils to inhibit the growth of STEC on ground beef.

These oils, derived from spices including clove and oregano, can exhibit antimicrobial properties.

They are identified as generally safe (GRAS) by the Food and Drug Administration and Department of Agriculture Food Safety Inspection Service and may help inhibit pathogen growth during transportation and retail.

Post-harvest antimicrobial interventions applied during the animal-to-product conversion process, such as thermal carcass treatments and food-grade chemical sprays of beef subprimals, are said to be effective STEC controls at the beef processor level.

Scientific validation for selection and use of these technologies is based upon lab and in-plant studies conducted since the mid-1990s targeting E. coli O157:H7 or other native "indicator" microbial populations, said Acuff’s presentation abstract.

There is much less knowledge about their effectiveness against other STECs to support HACCP programs and processor decision-making.

Data from the Centers for Disease Control and Prevention says STEC causes 230,000 cases of illness annually. Slightly more than 1% results in hospitalization and life-threatening complications.

The presentations were made at the Governor’s Conference/STEC CAP Annual Conference May 27-29.

Part in overall project

Texas A&M is one of 15 universities involved in the STEC research that was funded by a five-year, $25m grant from the US Department of Agriculture.

Acuff said they are into the third year of the project, focusing on intervention which is the third of the objectives.

“The challenge is to pull all the data together and make an integrated report as it involves animal production, harvest, processing, marketing and the consumer and you need to make that understandable to all parties," ​he said.

“It was good to get together [at the conference] and see what each are finding and to catch up with what is going on.

“I was interested in the work with consumers that was presented with the data on how celebrity chefs teach consumers who might be watching and how they could provide valuable information if they communicated better.”

The other objectives are detection, biology, risk analysis and assessment, risk management and communication and involve researchers from the University of Arkansas, California-Davis, California-Tulare, Delaware, Kansas State, New Mexico State, North Carolina State and Virginia Tech. 

Related topics Food Safety & Quality

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