Over the past 60 years, E. coli has been the primary model organism for gene sequencing and recombinant DNA experiments. While the majority of these E. coli strains are harmless, there exist a few strains that, when present in the human body, cause severe food poisoning and intestinal havoc.
UC Davis is a member of a large-scale research project funded by the United States Department of Agriculture (USDA) geared toward reducing amounts of the E. coli pathogen in cattle and processing plants. They also seek to educate both restaurants and individual consumers in safe storage and preparation methods.
According to the USDA grant proposal, there are 9.4 million cases of food-borne illness every year, with an estimated social cost of $1.4 trillion in sick days and loss of productivity. One of the primary culprits behind these extreme cases is the E. coli strain 0157:H7, but other harmful strains include the 0104 strain.
“Over 50 people were killed in Germany [in 2011] by the 0104 strain,” said Terry Lehenbauer, the associate director of the UC Davis Veterinary Medicine Teaching and Research Center (VMTRC).
The strains the researchers are looking to minimize are in the groups Shigella and enterohemorrhagic E. coli (EHEC). The Shigella strains produce toxins, known as Shiga toxins, which are responsible for dysentery, colitis and renal failure. The EHEC, of which 0157:H7 and 0104 are members, produce other toxins called verotoxins that cause bloody stools, and infection and inflammation of the large intestine.
E. coli can infect anyone, but the highest at-risk groups are the elderly, young children and people with diabetes.
The portion of this project based in Davis is focused on eliminating the presence of these bacteria on animal hides and looking for ecologically sound methods of making food processing safer. Researchers are using specific electrical currents that are harmless to the animals but inactivate E. coli cells.
The research will also focus on learning more about these endemic pathogens.
“Know your enemy,” said James Cullor, director of the VMTRC. “We are working on diagnostic methodologies so we can find these things, track them and find out their biology.”
Davis’ role in the project also delves into the consumer side of prevention. Davis will be developing intervention strategies and training programs to teach proper handling and preparation of potentially contaminated food products.
“We videotaped a group of people preparing hamburgers and salads and saw that less than half of them used soap when washing their hands,” said Christine Bruhn, director of the Center for Consumer Research at UC Davis.
Bruhn’s research has shown that the majority of infections are due to poor sanitation in the home and kitchen, so she will be part of an effort to work with hospitals and health care providers to teach people about proper preparation and sanitation.
These programs will work to teach new generations proper food preparation methods that were common knowledge to previous generations.
“Less than 2 percent [of people] feed the other 98 percent. Each generation is getting farther and farther away from the basic knowledge of food safety,” Cullor said.
The USDA project is a five year, $25 million endeavor with specific goals set up along the way. Aside from UC Davis, the other involved institutions include University of Delaware, New Mexico State University, Texas A&M, Virginia Tech, the University of Arkansas and the USDA Agricultural Research Service.
HUDSON LOFCHIE can be reached at science@theaggie.org.
