title: A preliminary survey of antibiotic resistance of Salmonella in market-age swine.
abstract: We conducted an epidemiological survey of antibiotic resistance in Salmonella recovered from market-age swine at five different Texas farms. These farms, which were visited between October 1997 and June 1998, were completely integrated, farrow-to-finish operations. Samples were taken from the lymph nodes and cecal contents at the time of slaughter. The Salmonella samples that were recovered were sent to the National Veterinary Services Laboratory for serotyping. Antibiotic resistance was determined using the Dispens-O-Disc Susceptibility Test System using 13 different antimicrobial agents that have been utilized in either veterinary medicine, human medicine, or both. Preliminary analysis of the first 183 samples out of approximately 400 Salmonella samples recovered indicated that 183 (100%) of the Salmonella samples were resistant to penicillin G, and 122 (66.7%) were resistent to chlortetracycline. Six (3.3%) were resistant to four antibiotics (chlortetracycline, penicillin G, streptomycin, and sulfisoxazole), and 25 (13.7%) were resistant to three antibiotics (chlortetracycline, penicillin G, and either streptomycin, sulfisoxazole, or ampicillin). Variation was seen between serotypes, with four out of five S. agona samples (80.0%) and two out of eight S. derby samples (25.0%) resistant to four antibiotics. Variation in antibiotic resistance also was seen between farms. There is an increasing concern about the prevalent usage of antibiotics in medicine and agriculture and the relationship this may have on emerging microbial resistance patterns; therefore, continued surveillance on antibiotic resistance in animal production is warranted.
authors.affiliation: Department of Veterinary Anatomy and Public Health, Texas A&M University, College Station 77843, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Farrington
authors.forename: R B
authors.initials: RB
authors.lastname: Harvey
authors.forename: S A
authors.initials: SA
authors.lastname: Buckley
authors.forename: L H
authors.initials: LH
authors.lastname: Stanker
authors.forename: P D
authors.initials: PD
authors.lastname: Inskip
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents; D004352:Drug Resistance, Microbial; D018432:Drug Resistance, Multiple; D008460:Meat; D008826:Microbial Sensitivity Tests; D012475:Salmonella / Q000187:drug effects*; D012481:Salmonella Infections, Animal / Q000453:epidemiology / Q000382:microbiology*; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000382:microbiology*; D013781:Texas / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents