My laboratory studies the molecular basis of pathogenesis of bacteria, with a focus on pathogens that cause food-borne disease. At present, the research program has two emphases. The first project focuses on Escherichia coli O157:H7 shedding from cattle. This bacterium is a major food safety pathogen and the cause of severe diarrhea and hemolytic uremic syndrome in humans. Our long-term goal is to eradicate this pathogen from cattle herds. Previous work focused on determining the role of E. coli O157:H7 acid resistance on shedding of the organism from cattle. This approach involved targeting the enzyme products of acid resistance genes, rendering the pathogen acid sensitive and therefore vulnerable to the stomach acid of cattle (and humans). A second strategy being developed involves the use of E. coli O157:H7-specific bacteriophage for reducing or removing this pathogen from cattle. This approach has promise because it would specifically remove E. coli O157:H7, and not other commensal E. coli serotypes, from cattle.
The second research emphasis, similar to the first, involves reducing Salmonella from cattle and poultry. Salmonella enterica serotypes cause disease in many food animals, including cattle, and also move into the human food supply where they can cause gastroenteritis (food poisoning) and sometimes severe, systemic disease in people. We are developing strategies involving Salmonella bacteriophage to reduce or remove this pathogen from cattle and poultry. Success with this approach would reduce the losses in animal production due to Salmonella disease, and concomitantly reduce the number of human cases of salmonellosis acquired from contaminated food.