title: Evaluation of antimicrobial resistance profiles of escherichia coli isolates of broiler chickens at slaughter in Alberta, Canada.
abstract: This study was conducted to investigate antimicrobial resistance profiles of Escherichia coli isolates from broiler chickens in Alberta, Canada. Cecal contents of broiler chickens from 24 flocks were collected at slaughter between January and March 2005 for culture and antimicrobial susceptibility testing against a panel of 15 antimicrobials using a broth microdilution technique. Of 600 E. coli isolates tested, 475 (79.2%) were resistant to one or more antimicrobials, 326 (54.3%) were resistant to three or more antimicrobials, 65 (10.8%) were resistant to five or more antimicrobials, and 15 (2.5%) were resistant to seven or more antimicrobials. The most common resistance was to tetracycline (69.2%), followed by streptomycin (48.2%), kanamycin (40.3%), and sulfisoxazole (38.0%). None of the E. coli isolates were resistant to amikacin, ceftriaxone, or ciprofloxacin. Of the isolates that were resistant to two or more antimicrobials, the most common multidrug resistance patterns were streptomycinte-tracycline (44.0%), streptomycin-sulfisoxazole-tetracycline (30.7%), and kanamycin-streptomycin-sulfisoxazole-tetracycline (23.5%). Resistance to tetracycline and kanamycin (odds ratio = 46.7, P = 0.0001) was highly associated, followed by resistance to streptomycin and sulfisoxazole (odds ratio = 12.0, P = 0.0001), and streptomycin and tetracycline (odds ratio = 10.3, P = 0.0001). The flock level prevalence of resistance varied from 16.7% for chloramphenicol to 100.0% for ampicillin, streptomycin, sulfisoxazole, and tetracycline. The results of this study provided baseline information on antimicrobial susceptibility of E. coli isolates of broiler chickens at slaughter in Alberta, which can serve as a bench mark for future research.
authors.affiliation: Food Safety and Animal Health Division, Alberta Agriculture and Rural Development, O.S. Longman Building, 6909-116 Street, Edmonton, Alberta, Canada T6H 4P2. chunu.mainali@gov.ab.ca.
authors.forename: Chunu
authors.initials: C
authors.lastname: Mainali
authors.forename: Margaret
authors.initials: M
authors.lastname: McFall
authors.forename: Robin
authors.initials: R
authors.lastname: King
authors.forename: Rebecca
authors.initials: R
authors.lastname: Irwin
mesh_terms: D000416:Alberta / Q000453:epidemiology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002645:Chickens / Q000382:microbiology*; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial / Q000187:drug effects; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D015995:Prevalence
chemical_list: D000900:Anti-Bacterial Agents