title: Antimicrobial resistance in Salmonella enterica serovar Dublin isolates from beef and dairy sources.
abstract: Salmonella enterica serovar Dublin (S. Dublin) is a cattle-adapted Salmonella serovar, so if antimicrobial resistance in S. Dublin arises as a result of antimicrobial use this most likely occurs within the cattle reservoir without impact from antimicrobial use in humans. We tested the antimicrobial resistance of bovine-origin S. Dublin isolates from 1986 through 2004 using a standard disk diffusion method. High proportions of isolates throughout the time period were resistant to one or more antimicrobials, and a marked increase in resistance to ceftazidime occurred between 2000 and 2004. Dairy-origin isolates were more likely to be resistant to several antibiotics than were isolates from beef operations where exposure to antimicrobials is likely to be less frequent. Plasmid analysis of a subset of isolates also supported the hypothesis that antimicrobial resistance traits in the cattle-adapted serovar Dublin were acquired within the bovine host environment.
authors.affiliation: Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA. madavis@vetmed.wsu.edu
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Davis
authors.forename: Dale D
authors.initials: DD
authors.lastname: Hancock
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Besser
authors.forename: Joshua B
authors.initials: JB
authors.lastname: Daniels
authors.forename: Katherine N K
authors.initials: KN
authors.lastname: Baker
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Call
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy* / Q000382:microbiology; D015169:Colony Count, Microbial / Q000662:veterinary; D003612:Dairying; D004197:Disease Reservoirs / Q000662:veterinary; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field / Q000662:veterinary; D005260:Female; D008297:Male; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D015205:Northwestern United States; D010957:Plasmids; D012481:Salmonella Infections, Animal / Q000188:drug therapy* / Q000382:microbiology*; D019779:Salmonella enterica / Q000145:classification / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents