When an outbreak of E. coli related to raw spinach consumption killed three people and sickened more than 200 in 2006, UC researchers mobilized. Their efforts helped to identify the strain of bacteria and trace the origins of the contamination to a San Benito County farm.

As an outcome of that incident, the Center for Produce Safety opened at UC Davis in April with support from food industry leaders, the California Department of Food and Agriculture, and UC's Agriculture and Natural Resources division. Located within the UC Davis Western Institute for Food Safety and Security, the center plays a vital role in ensuring the safety of the state's produce supply.

With agriculture revenue of more than $31 billion a year, California is the nation's No. 1 food producer and exporter and the fifth-largest food supplier in the world. More than 150 countries around the globe rely on California agricultural products.

The Center for Produce Safety, through its partnership with produce producers and state agriculture and health agencies, is doing its part to support California's farmers. The center's mission includes initiatives for new research as well as field-level training and outreach to supplement industry safety programs already in place.

In addition to tackling natural sources of contamination, the Western Institute for Food Safety and Security created an agroterrorism training program. Certified by the U.S. Department of Homeland Security, the curriculum trains workers in the dangers of intentional contamination of agricultural products in processing plants, restaurants, hospital and school food services, and groceries.

UC's legions of cooperative extension advisors, microbiologists, veterinary medicine specialists and other food safety experts are laying a strong scientific foundation on which to build sound regulatory policy and industry best practices.

At stake is the health of consumers, the food industry and the environment. Here is a look at some of the UC efforts in produce safety.


Salinas Valley center home to pest detectives
Steven Koike, University of California Cooperative Extension farm advisor in plant pathology
http://ucanr.org/delivers

In the UC Cooperative Extension's Monterey County headquarters, farm advisors, working with university researchers, provide practical, field-oriented assistance to local producers.

The facility has a fully equipped microbiology lab used for detecting and diagnosing plant pathogenic fungi, bacteria, viruses and nematodes. Due to the urgency of the food safety situation, farm advisor Steven Koike has been focusing the lab's efforts to work on E. coli.

"Specifically, we are trying to develop information on where E. coli is coming from, how it moves around and how it survives in the field," says Koike.

Contamination rare. The task remains challenging with so many possible sources of contamination including livestock, wildlife, humans, irrigation water and even birds and insects. Yet, in the big picture, Koike says, the amount of contaminated produce that makes its way to consumers is small compared with the millions of pounds of food safely brought to market.

"In fact, very little of the produce has such concerns and the industry is doing a good job," Koike says. "Of course, given the occasional outbreak, industry is called upon to do better."

Consumers need to realize that "zero risk" is not realistic, he says. Produce, grown outside under natural conditions, will never be entirely free of the risk to exposure to E. coli and other organisms.

Detecting agroterrorism. Koike's lab is also part of the National Plant Diagnostic Network. Created in the aftermath of the 9/11 terrorist attacks, the network focuses on detecting and identifying plant pathogens deliberately introduced in an act of bioterrorism.

With funding from the U.S. Department of Agriculture Cooperative State Research, Education and Extension Service, the network includes five regional hubs based at land grant universities. The Western regional hub is located at UC Davis under the direction of plant pathology professor Rick Bostick. The Western consortium encompasses universities and state departments of agriculture throughout the West as well as U.S. territories in the Pacific.


Buffers separate cows from crops

Rob Atwill, interim director, Western Institute for Food Safety and Security, professor of Environmental Animal Health and Medical Ecology, UC Davis School of Veterinary Medicine
http://wifss.ucdavis.edu

The Western Institute for Food Safety and Security, based at UC Davis, provides both research and outreach for consumers and food producers. Collaborating with U.S. and state departments of health and agriculture, other universities, and government agencies, the institute examines all stages of food production and works with producers to provide sound scientific basis for food-handling policies and best practices.

"UC has consistently provided critical input to the food industry," says Rob Atwill, interim institute director. "We'll continue to work with the industry to identify what's working and not working in the field. We'll be busy for years."

Spacing out. One of Atwil's ongoing research projects is testing the effectiveness of grassland buffer zones between fields of food crops and pastures where cattle roam. His studies have found that a zone of grasses even 3 to 6 feet wide under certain conditions will reduce the spread of E. coli and other harmful bacteria from livestock feces.

The soil acts as a filtration medium to curb the spread of bacteria from water runoff. Studies haven't yet found a specific variety of grasses more effective than another, but the trick, Atwill says, is to have a well-maintained buffer where the soil isn't compacted and water can drain through it rather than run off the surface.

"The buffer is made to help the ranchers," says Atwill. "The buffers are not a cure-all. To really promote food safety requires a variety of strategies."

Cows aren't the sole carrier of harmful pathogens. Birds, flies, wildlife, humans and dogs also can contaminate crops.

"I think we need to be unbiased," says Atwill, a doctor of veterinary medicine. "Wildlife as a vector for food-borne illness is underappreciated."

Changes in consumer buying habits have increased the risk for potential spreading of contamination. Before the advent of convenient, packaged loose greens, people bought lettuce and spinach in bunches or heads. If contamination with E. coli happened in the field, removing the outer leaves usually removed the problem.

Trade-offs. The produce companies are motivated to secure the safety of their products, and consumers are demanding it. But on the policy side, Atwill says there are issues worth debating.

"How safe do we want our food to be?" he says. "Safety will come at a cost."

Erecting 8-foot-high fences across the rural landscape and trapping large numbers of wild animals will change the environment.

"Is that the landscape we want?" Atwill asks. "Or do we accept some illness each year to have open spaces?"


UC delivers before and after the harvest

Trevor Suslow, extension research specialist, Postharvest Quality and Safety, UC Davis Department of Plant Sciences
http://ucgaps.ucdavis.edu


UC's food safety mission extends from farm to consumer. Each step of the food production and delivery cycle delivers its own challenges. Cooperative Extension specialist Trevor Suslow focuses on post-harvest microbiology and maintaining produce quality through transportation and distribution.

"From the moment of harvest, it's a race to the consumer," Suslow says. "With fresh produce you really are racing the clock."

Testing testing. The 2006 E. coli outbreak in fresh spinach triggered intense emphasis on produce testing to prevent contaminated products from reaching consumer dinner tables. The level of testing has grown dramatically over the last year, Suslow says. But to make sure the freshest produce gets to market quickly, producers can't hold fruits and vegetables in a warehouse for extended periods. Most fresh produce has about a 10-hour testing window, he says. UC researchers are evaluating rapid testing methods to determine the best practices for quick and careful screening.

On the hunt. Much of the university's food safety research and education efforts involves prevention tactics. Once fresh produce is contaminated, it's difficult to remove the pathogens.

"We still don’t have a clear handle on how contamination arises," says Suslow. "There is no guaranteed ‘kill’ step."

Efforts continue throughout the UC system to identify potential sources of food-borne sickness. Working closely with field advisors, campus researchers help isolate contamination sources, ruling out some suspects and intensifying the hunt for yet undetected risks.

"We from the university are addressing irrigation water in the Salinas and Central Coast areas and trying to see if it's a source of contamination," says Suslow.

So far, no association has been found between irrigation water and contamination, he says. During the studies, university researchers were able to suggest methods and frequency for sampling the water so growers can monitor water quality.

With a nationwide emphasis on food safety, Suslow would like to see more funding backing up the research and monitoring efforts.

"Given what many people are calling for in improvements in our food supply, government is going to have to allocate more resources to regulatory agencies," says Suslow.