title: Risk factors for Escherichia coli O157 on beef cattle ranches located near a major produce production region.
abstract: Our goal was to identify climate variables and management practices associated with the presence of E. coli O157 in rangeland cow-calf operations located in a major leafy green production region in the California Central Coast. E. coli O157 was present in 2·6% (68/2654) of faecal, 1·5% (3/204) of water and 1·1% (1/93) of sediment samples collected on eight ranches over 2.5 years. Five (62·5%) ranches were positive at least once during the study. The odds of detecting E. coli O157 in faecal samples was higher during periods of higher maximum soil temperature, higher maximum relative humidity, and larger herd sizes, but decreased as wind speed increased. Molecular subtyping of isolates from cattle faeces and streams/sediments suggested minimal movement of strains between ranches. The findings suggest that E. coli O157 prevalence is relatively low on cow-calf ranches in this region, spatially constrained, but may vary by weather conditions and herd size.
authors.affiliation: Western Center for Food Safety,University of California-Davis,Davis, CA,USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Benjamin
authors.affiliation: Western Center for Food Safety,University of California-Davis,Davis, CA,USA.
authors.forename: M T
authors.initials: MT
authors.lastname: Jay-Russell
authors.affiliation: Western Center for Food Safety,University of California-Davis,Davis, CA,USA.
authors.forename: E R
authors.initials: ER
authors.lastname: Atwill
authors.affiliation: Produce Safety and Microbiology Research Unit,U.S. Department of Agriculture,Agricultural Research Service, Western Regional Research Center, Albany, CA,USA.
authors.forename: M B
authors.initials: MB
authors.lastname: Cooley
authors.affiliation: Produce Safety and Microbiology Research Unit,U.S. Department of Agriculture,Agricultural Research Service, Western Regional Research Center, Albany, CA,USA.
authors.forename: D
authors.initials: D
authors.lastname: Carychao
authors.affiliation: University of California Cooperative Extension,Templeton, CA,USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Larsen
authors.affiliation: Produce Safety and Microbiology Research Unit,U.S. Department of Agriculture,Agricultural Research Service, Western Regional Research Center, Albany, CA,USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Mandrell
mesh_terms: D000383:Agriculture / Q000379:methods*; D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D002140:California / Q000453:epidemiology; D002417:Cattle; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D019453:Escherichia coli O157 / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D005243:Feces / Q000382:microbiology*; D008685:Meteorological Concepts; D058889:Molecular Typing; D015995:Prevalence; D012307:Risk Factors; D014871:Water Microbiology