Vet Medicine launches a new approach to E. coli food safety

Jan. 30, 2009

by Tania Banak

Infection by Eschericia.coli O157:H7 from undercooked cattle meat proves deadly to about 60 people in the U.S. each year. While testing is available to detect the presence of the bacterium in raw meat, researchers at UW-Madison would prefer to address the problem before the meat is sent to market.

"Can we find ways to reduce the incidence of this bacterium in cattle, so that we can decrease the risk of infections in humans?" asks Dorte Dopfer, a veterinary epidemiologist and new faculty member in food animal production medicine at the UW-Madison School of Veterinary Medicine.

She and colleagues from the UW-Madison College of Agricultural and Life Sciences (CALS) and Texas A&M University have teamed up to approach this question in an innovative and unique way. By linking theory (mathematical modeling) to real-world data (microbiology and epidemiology), the trio hopes to be able to identify new strategies to control disease in humans.

Dopfer notes that food safety research is multi-disciplinary. Which organisms are present and where in the food chain? In what quantity? How will the organism behave as it spreads through groups of individuals?

Instead of approaching the problem from just one viewpoint, she and her colleagues will combine their expertise in order to gain a broader perspective.

"It's not easy," Dopfer admits. "Each specialty area uses a language of its own."

By strategically collecting data, she hopes that microbiologists and epidemiologists will eventually be able to provide data in a format that will give mathematical modelers the information they need to make predictions and try out novel disease interventions.

"Cattle are the main reservoir of verotoxinogenic E. coli, or VTECs," Dopfer says. "They themselves do not become diseased, but if this particular form of E. coli multiplies to certain levels within the animals and their manure, it can accumulate in or on the meat and infect humans, to whom it may become very harmful."

By combining the three disciplines, she hopes to get a clearer sense of what it is in a cow and its environment that permits VTECs to multiply to levels where they cause problems for humans. Once that is established, scientists can determine the best time and method of intervention.

"Should we vaccinate the cows? Should we clean their water troughs? Should we clean their pens more frequently? Or should a combination of all of these be practiced?" she asks. "Integrating theory with real-world data will provide us with better answers. Then we also need to look at the economics, or practicality, of what we find."

Collaborating with Dopfer are Chuck Kaspar, a CALS microbiologist, and Renata Ivanek, a veterinarian, epidemiologist and mathematical modeler from Texas A&M University.