Ecology and Molecular Epidemiology of Zoonotic Bacterial Pathogens Asociated with Dairy Farms

Objective 1: Determine the environmental compartments within dairy farming systems that support the survival of zoonotic pathogens (Salmonella enterica, Shigatoxigenic Escherichia coli, and Listeria monocytogenes), characterize their contribution to the pathogen content of raw milk and meat, and test remediation methods for the reduction of bacterial food borne pathogens in the dairy farm environment. Objective 2: Isolate Shiga-toxigenic E. coli from feces of dairy cows to determine the load and profile of strains entering the meat supply from culled dairy cows. Objective 3: Analyze Listeria monocytogenes isolated from the dairy farm environment and from milk for biofilm formation and virulence, and investigate the efficacy of new and existing methods and treatments for the elimination or control of biofilms in milking equipment. Objective 4: Compare and contrast salmonellae that behave as commensal inhabitants of the dairy cow gut, and may be emerging threats as human pathogens, with strains known to inhabit cows transiently and/or to cause disease in humans and animals. Objective 5: Analyze the colonic bacterial metagenomes in individual cows with known, long-term pathogen shedding profiles to identify population changes within and across animals that are associated with pathogen carriage.