title: Antimicrobial resistance of Salmonella isolated from finishing swine and the environment of 60 Alberta swine farms.
abstract: The study objective was to describe and evaluate antimicrobial resistance profiles in Salmonella isolated from Alberta swine finishing farms. Salmonella isolates (n = 322) were obtained from 192 fecal and 84 environmental samples of the 60 Salmonella-positive swine finishing farms. Isolates were classified susceptible, intermediate or resistant based on NCCLS guidelines. More than half of the isolates (53.4%) were susceptible to all of the 18 antimicrobials in the testing panel. No resistance was observed to amikacin, amoxicillin/clavulanic acid, cefoxitin, ceftiofur, ceftriaxone, cephalothin, ciprofloxacin, imipenem or nalidixic acid. Less than 1% of isolates were resistant to apramycin, gentamicin and trimethoprim/sulfamethoxazole. Higher frequencies of resistance were observed for chloramphenicol (4.7%), ampicillin (7.8%), kanamycin (11.8%), sulfamethoxazole (21.1%), streptomycin (25.5%) and tetracycline (38.8%). Eleven Salmonella serovars had isolates with resistance to > or =3 antimicrobials. The most frequently resistant serovar was Salmonella Derby, with 27 (38.0%) isolates resistant to > or =3 antimicrobials, including resistance to five and six antimicrobials. An absence of resistance to cephalosporins and fluoroquniolones and a low proportion of isolates resistant to amikacin, amoxicillin/clavulanic acid, apramycin, gentamicin and trimethoprim/sulfamethoxazole are encouraging findings from public health and animal health perspectives. Frequent resistance observed for ampicillin, kanamycin, sulfamethoxazole, streptomycin and tetracycline, antimicrobials commonly used in veterinary medicine for decades, indicates an urgent need to utilize these antimicrobials more prudently if their benefits are to be preserved.
authors.affiliation: Food Safety Division, Alberta Agriculture, Food and Rural Development, Edmonton, Alta., Canada T7H 4P2. andrijana_rajic@hc-sc.gc.ca
authors.forename: Andrijana
authors.initials: A
authors.lastname: Rajić
authors.forename: Margaret E
authors.initials: ME
authors.lastname: McFall
authors.forename: Anne E
authors.initials: AE
authors.lastname: Deckert
authors.forename: Richard
authors.initials: R
authors.lastname: Reid-Smith
authors.forename: Ken
authors.initials: K
authors.lastname: Manninen
authors.forename: Cornelius
authors.initials: C
authors.lastname: Poppe
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Dewey
authors.forename: Scott A
authors.initials: SA
authors.lastname: McEwen
mesh_terms: D000416:Alberta; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D015169:Colony Count, Microbial; D024901:Drug Resistance, Multiple, Bacterial; D005243:Feces / Q000382:microbiology; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D012475:Salmonella / Q000145:classification / Q000187:drug effects* / Q000254:growth & development; D012481:Salmonella Infections, Animal / Q000188:drug therapy* / Q000382:microbiology; D013552:Swine; D013553:Swine Diseases / Q000188:drug therapy* / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents