title: Prevalences of resistance to seven antimicrobials among fecal Escherichia coli of swine on thirty-four farrow-to-finish farms in Ontario, Canada.
abstract: Fecal specimens were composited and a hydrophobic-grid membrane-filter method was used to measure antimicrobial resistance to ampicillin 16 micrograms/ml, carbadox 30 micrograms/ml, gentamicin 4 mu/ml, nitrofurantoin 32 micrograms/ml, spectinomycin 16 micrograms/ml, sulfisoxazole 32 micrograms/ml and tetracycline 8 micrograms/ml among 8119 Escherichia coli isolates from 68 fecal samples collected on 34 farrow-to-finish swine farms marketing over 500 hogs/yr. The overall prevalences of resistance to antimicrobials among these isolates were: ampicillin 29%, carbadox 3.5%, gentamicin 0.6%, nitrofurantoin 27%, spectinomycin 28%, sulfasoxizole 38% and tetracycline 71%. Thirty to seventy-six per cent of the variations in prevalences were explained by between-farm differences.
authors.affiliation: Department of Population Medicine, University of Guelph, Ontario, Canada.
authors.forename: R H
authors.initials: RH
authors.lastname: Dunlop
authors.forename: S A
authors.initials: SA
authors.lastname: McEwen
authors.forename: A H
authors.initials: AH
authors.lastname: Meek
authors.forename: W D
authors.initials: WD
authors.lastname: Black
authors.forename: R M
authors.initials: RM
authors.lastname: Friendship
authors.forename: R C
authors.initials: RC
authors.lastname: Clarke
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects* / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000517:prevention & control / Q000662:veterinary*; D005243:Feces / Q000382:microbiology; D009864:Ontario / Q000453:epidemiology; D015995:Prevalence; D013552:Swine; D013553:Swine Diseases / Q000188:drug therapy / Q000453:epidemiology / Q000517:prevention & control*
chemical_list: D000900:Anti-Bacterial Agents