title: Escherichia coli O157:H7 vaccine field trial in 9 feedlots in Alberta and Saskatchewan.
abstract: A feedlot trial was conducted to assess the efficacy of an Escherichia coli O157:H7 vaccine in reducing fecal shedding of E. coli O157:H7 in 218 pens of feedlot cattle in 9 feedlots in Alberta and Saskatchewan. Pens of cattle were vaccinated once at arrival processing and again at reimplanting with either the E. coli O157:H7 vaccine or a placebo. The E. coli O157:H7 vaccine included 50 microg of type III secreted proteins. Fecal samples were collected from 30 fresh manure patties within each feedlot pen at arrival processing, revaccination at reimplanting, and within 2 wk of slaughter. The mean pen prevalence of E. coli O157:H7 in feces was 5.0%; ranging in pens from 0% to 90%, and varying significantly (P < 0.001) among feedlots. There was no significant association (P > 0.20) between vaccination and pen prevalence of fecal E. coli O157:H7 following initial vaccination, at reimplanting, or prior to slaughter.
authors.affiliation: donkersg@telusplanet.net
authors.forename: Joyce
authors.initials: J
authors.lastname: Van Donkersgoed
authors.forename: Dale
authors.initials: D
authors.lastname: Hancock
authors.forename: Dragan
authors.initials: D
authors.lastname: Rogan
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Potter
mesh_terms: D000416:Alberta; D000818:Animals; D001428:Bacterial Vaccines / Q000592:standards*; D002417:Cattle; D002418:Cattle Diseases / Q000517:prevention & control*; D015169:Colony Count, Microbial / Q000662:veterinary; D004927:Escherichia coli Infections / Q000517:prevention & control / Q000662:veterinary*; D019453:Escherichia coli O157 / Q000276:immunology* / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology*; D011897:Random Allocation; D012525:Saskatchewan
chemical_list: D001428:Bacterial Vaccines