title: Antimicrobial resistance in Escherichia coli isolated from retail milk-fed veal meat from Southern Ontario, Canada.
abstract: This study estimated the prevalence of Escherichia coli isolates in fresh retail milk-fed veal scallopini pieces obtained from grocery stores in Ontario, Canada. In addition, the prevalence and antimicrobial resistance patterns were examined for points of public health significance. One hundred fifty-three milk-fed veal samples were collected over the course of two sampling phases, January to May 2004 and November 2004 to January 2005. E. coli isolates were recovered from 87% (95% confidence interval, 80.54 to 91.83%) of samples, and antimicrobial susceptibility testing was conducted on 392 isolates. The prevalence of resistance to one or more antimicrobials was 70% (274 of 392), while the resistance to five or more antimicrobials was 33% (128 of 392). Resistance to ceftiofur (2.8%), ceftriaxone (3.6%), nalidixic acid (12%), and ciprofloxacin (3.8%) alone or in combination was observed. Eighty-five resistance patterns were observed; resistance to tetracycline only (7.4%) was observed most frequently. Individual antimicrobial resistance prevalence levels were compared with grain-fed veal and retail beef data from samples collected in Ontario. In general, resistance to individual antimicrobials was observed more frequently in E. coli isolates from milk-fed veal than in isolates from grain-fed veal and beef. Resistance to one or more antimicrobials and to five or more antimicrobials in E. coli isolates was more frequent in isolates from milk-fed veal than in isolates from grain-fed veal and beef. This study provides baseline data on the occurrence of resistance in E. coli isolates from milk-fed veal that can be compared with data for other commodities. Additionally, E. coli resistance patterns may serve as an indicator of antimicrobial exposure.
authors.affiliation: Laboratory for Foodborne Zoonoses, Public Health Agency of Canada, 120-255 Woodlawn Road West, Guelph, Ontario, Canada N1H 8J1. angela.cook@phac-aspc.gc.ca
authors.forename: Angela
authors.initials: A
authors.lastname: Cook
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Reid-Smith
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Irwin
authors.forename: Scott A
authors.initials: SA
authors.lastname: McEwen
authors.forename: Virginia
authors.initials: V
authors.lastname: Young
authors.forename: Kelly
authors.initials: K
authors.lastname: Butt
authors.forename: Carl
authors.initials: C
authors.lastname: Ribble
mesh_terms: D000821:Animal Feed; D000822:Animal Husbandry; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002417:Cattle; D015169:Colony Count, Microbial; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000254:growth & development / Q000302:isolation & purification*; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D008460:Meat / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D008892:Milk / Q000382:microbiology*; D009864:Ontario; D015995:Prevalence
chemical_list: D000900:Anti-Bacterial Agents