SAMPLING IN FRESH PRODUCE PRODUCTION REGIONS ON THE CALIFORNIA CENTRAL COAST

We hypothesize that vertebrate populations (especially cattle and wild birds) function as a key source of E. coli O157:H7 (EcO157) contamination of watersheds where leafy greens and other leafy vegetables are grown; that climate, landscape attributes, and irrigation practices correlate with increased risks of EcO157 and commensal E. coli contamination; and in-field contamination of leafy greens plants with EcO157 relates to combinations of production practices and environmental risk factors in the Central California Coast, specifically, the San Juan Valley region. The major objectives of this grant to UC Davis are to collaborate with, and assist, ARS in (1) quantifying environmental loading by vertebrate sources, especially feral swine, (2) characterizing the predisposing conditions for hydrological transport of EcO157 and E. coli to leafy green fields, (3) identifying the in-field mechanism(s) of contamination of leafy greens, and (4) developing and disseminating educational materials for growers of fresh produce and the livestock community about microbial water quality, potential impacts on down-stream stakeholders, and effective BMPs for improving water quality.