title: Antimicrobial resistance of fecal Salmonella spp. isolated from all phases of pig production in 20 herds in Alberta and Saskatchewan.
abstract: Salmonella spp. (n = 468), isolated from the feces of sows, nursery, and grow-finish pigs in 20 farrow-to-finish herds in Alberta and Saskatchewan, were tested for susceptibility to 16 antimicrobials. No resistance was identified to amikacin, amoxicillin-clavulanic acid, ceftiofur, ceftriaxone, ciprofloxacin or nalidixic acid, and less than 1% of the isolates were resistant to cefoxitin and gentamicin. Isolates were most commonly resistant to tetracycline (35%) and sulfamethoxazole (27%). Overall, 59% of the Salmonella were susceptible to all 16 drugs (pansusceptible). Isolates from sows were more likely to be pansusceptible than isolates from nursery or grow-finish pigs. Resistance to 2 or more drugs occurred in 29% of the isolates and was significantly more likely to occur in Salmonella from nursery pigs than from sows. The odds of resistance to 4 of the drugs, streptomycin, ampicillin, kanamycin and cephalothin, were significantly higher in isolates from nursery pigs than grow-finish pigs, while the odds of resistance to 2 drugs, tetracycline and streptomycin, were higher in Salmonella from nursery pigs than from sows. More age-specific risk factor studies are needed to investigate these differences between production phases.
authors.affiliation: Department of Large Animal Clinical Sciences, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4. leigh.rosengren@vetepi.com
authors.forename: Leigh B
authors.initials: LB
authors.lastname: Rosengren
authors.forename: Cheryl L
authors.initials: CL
authors.lastname: Waldner
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Reid-Smith
authors.forename: Sylvia L
authors.initials: SL
authors.lastname: Checkley
authors.forename: Margaret E
authors.initials: ME
authors.lastname: McFall
authors.forename: Andrijana
authors.initials: A
authors.lastname: Rajić
mesh_terms: D000367:Age Factors; D000416:Alberta; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015169:Colony Count, Microbial / Q000662:veterinary; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D005243:Feces / Q000382:microbiology*; D005260:Female; D008297:Male; D008826:Microbial Sensitivity Tests; D012307:Risk Factors; D012475:Salmonella / Q000187:drug effects* / Q000302:isolation & purification; D012481:Salmonella Infections, Animal / Q000188:drug therapy* / Q000382:microbiology; D012525:Saskatchewan; D013552:Swine; D013553:Swine Diseases / Q000188:drug therapy* / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents