Agriculture and environment
E.coli Research, March 2007
Narrator: In 2006, more than 200 people were sickened, and at least three people died, after eating spinach contaminated with the E.coli bacteria. The deadly outbreak was traced to a San Benito County, California farm and the source has since been determined to be from either cattle or wildlife. To prevent future outbreaks in food crops, growers and processors are working with University of California scientists to study the biology, ecology and possible sources of E.coli in agricultural systems.
Royce Larsen: We’re now going to take a look at livestock, wildlife and movement of E.coli. We want to know what the sources are, what the potentials are, what the risks are with them and then, if they are a source, how does it move?
Narrator: Larsen is one of several university advisors collaborating with the United States Department of Agriculture on a four-year, 1.7 million dollar research initiative. Robert Mandrell, of the USDA’s Agricultural Research Service, is co-leader of the project.
Robert Mandrell: Each of the team members has expertise very appropriate to this work.
Our laboratory, for example, is going to be intensively involved in testing the samples, isolation of pathogens if they’re there and they’re also fingerprinting those pathogens by a variety of techniques and one relatively new technique, creating the database of strains and fingerprints. Knowledge is going to be important because there may be things that aren’t as much of a risk as we think they are – there may be others that have been undiscovered that are more of a risk than we know and that’s what these kinds of science studies are – research studies are about – to get some information.
Narrator: That’s just what Trevor Suslow, a UC Davis-based postharvest specialist has been doing. For years, Suslow has been working with local farm advisors on E.coli-related projects, including the sampling of lettuce plants in California’s Salinas Valley – the source of previous E.coli outbreaks.
Trevor Suslow : What we try and do is really take a system approach to the kind of risk and also the types of control measures or prevention practices that you would have to have to go as far as you can to assure safe food supply. We initiated a three-year study looking at a little over twenty different on-farm reservoirs up and down the Salinas Valley and then really characterizing them for the kinds of microbial water quality indicators and then suggest both sampling methodology and sampling frequency and how that related to pathogen levels. In this case, in all of the three years of testing, we’ve not found detectable levels of pathogens in the waters.
Narrator: Meanwhile, plans for the four-year, USDA-funded study to trace the ecology and epidemiology of E.coli are underway.
Royce Larsen: Our first year is outreach, planning, meeting with the cattlemen and other groups to try to get things set up, get cooperators and producers to work with us; let them know what the issue is and then this coming winter is when we’ll actually start the sampling and we’ll be doing that for another three years and hopefully be able to get some answers. Ultimately, we want to make sure the food is safe for the public. So, we want to get some answers – what is really going on, so that we can give some really good, sound science, so that the food is safe, but so is the industry and people’s lives can continue and ranchers can continue and farming can continue. So, that’s what we’re after.
Narrator: As for consumers concerned about their risk of E.coli contamination from fresh produce, researchers emphasize that deadly outbreaks are rare.
Robert Mandrell: It’s an incredibly low percentage of the time that this would ever be a risk, so all you have to think about is how much produce you’re eating and you don’t have a problem. Having said that, the produce industry is more sensitive to this even than any of us probably, because they’re the ones who are really affected by it. So, they know that even if it’s a low probability event, another one – because of the media attention – really creates problems for everyone.
Narrator: In Monterey County, I’m Larissa Branin.
California growers and processors are working with University of California scientists to study the biology, ecology and possible sources of E.coli in agricultural systems.
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