USDA Grant to Support Rearch of E. coli O157 Supershedders
Microbiologist Andy Benson and his research team at the University of Nebraska-Lincoln received a five-year, $2.35 million grant from the U.S. Department of Agriculture to study cattle known as “supershedders,” animals that shed an unusually large number of E. coli O157:H7.
E. coli O157:H7 long has been known to colonize the bovine gut. Although it causes no disease symptoms in the animals, it can be transmitted to humans through improperly cooked beef, among other ways.
"Studies looking at animal-level factors have shown that while many animals may be carriers of the organism, a small portion of animals shedding the organism at very high levels may account for much of the transmission risk," added Benson, the W. W. Marshall professor of biotechnology in UNL's department of food science and technology.
Benson hopes this newly funded research will lead to pre-slaughter intervention strategies to prevent E. coli O157:H7 illness in humans.
The goal is to try to associate organisms in the cattle's gastrointestinal tract with genes in the animals to see if some of those interactions are causing certain animals to become supershedders of the E. coli pathogen, while others that may have E. coli present do not shed it in unusual numbers.
If those relationships can be understood, it may be possible to develop breeding and genetic programs to reduce the number of animals that shed high levels of E. coli O157:H7, salmonella, campylobacter and other pathogens.
"While epidemiologically oriented approaches have provided extensive information about the transmission patterns of the organism, they have essentially failed to come up with meaningful and effective pre-harvest interventions that work in beef production," Benson said. "On the other hand, breeding strategies, which have heretofore never been considered as an approach, could be implemented as a relatively simple intervention with potentially huge payoffs, ultimately reducing numbers of 'supershedders' that are released into feeding operations."
The USDA grant was part of the Food Safety Foundational Awards from the National Institute of Food and Agriculture.
Source: Press release from the Institute of Agriculture and Natural Resources University of Nebraska
