title: Prevalence of antimicrobial resistance in fecal generic Escherichia coil isolated in western Canadian cow-calf herds. Part I--beef calves.
abstract: The objective of this study was to describe antimicrobial resistance patterns in fecal generic Escherichia coli obtained from calves in western Canadian cow-calf herds. Susceptibility testing was completed on 1677 isolates obtained from 480 beef calves in 91 herds in the spring, and from 1187 isolates obtained from 394 calves in 45 herds in the fall of 2002. Resistance was rare to antimicrobials classified as being of very high importance to human health. Isolates were most commonly resistant to tetracycline, sulphamethoxazole, and streptomycin. Resistance to at least one antimicrobial was identified in 48.8% of the isolates collected in the spring, and 7.0% of those collected in the fall. Spring or fall calf resistance status was not associated with calf gender, breed, age of the dam, or if the calf was treated before sample collection. Calves < or = 3 days of age were less likely to be resistance positive than calves > 10 days of age.
authors.affiliation: Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4. sheryl.gow@usask.ca
authors.forename: Sheryl P
authors.initials: SP
authors.lastname: Gow
authors.forename: Cheryl L
authors.initials: CL
authors.lastname: Waldner
authors.forename: Andrijana
authors.initials: A
authors.lastname: Rajić
authors.forename: Margaret E
authors.initials: ME
authors.lastname: McFall
authors.forename: Richard
authors.initials: R
authors.lastname: Reid-Smith
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002170:Canada / Q000453:epidemiology; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D015169:Colony Count, Microbial / Q000662:veterinary; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D005243:Feces / Q000382:microbiology*; D005260:Female; D008297:Male; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D015995:Prevalence; D012307:Risk Factors; D012621:Seasons; D012737:Sex Factors
chemical_list: D000900:Anti-Bacterial Agents