title: Assessment of antibiotic resistance phenotype and integrons in Salmonella enterica serovar Typhimurium isolated from swine.
abstract: Salmonella enterica serovar Typhimurium (S. Typhimurium) isolated and identified from swine were subjected for the analysis of antibiotic resistance pattern and clinically important class 1 and 2 integrons. In addition, S. Typhimurium isolates exhibiting ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, tetracycline and florfenicol (ACSSuTF) resistance pattern as described in most Salmonella enterica serotype Typhimurium definitive type 104 (DT104) were characterized by polymerase chain reaction. All the isolates were resistant to more than four antibiotics and showed the highest resistance to streptomycin (94.1%), followed by tetracycline (90.1%), ampicillin (64.7%), chloramphenicol (56.8%) and gentamicin (54.9%). MIC value for the ten isolates ranged between 0.125-2 mug/ml for ciprofloxacin. Among the beta-lactams used, only one of the isolate exhibited resistance to ceftiofur (MIC 8 microg/ml). Sixty eight percent of these multi drug resistance (MDR) S. Typhimurium isolates carried clinically important class 1 integron with 1kb (aadA) and/or 2kb (dhfrXII-orfF-aadA2) resistance gene cassettes. This study reports the increasing trend of multi drug resistance (MDR) S. Typhimurium with clinically important class 1 integron in pigs. In addition, emergence of the ACSSuTF-type resistance in S. Typhimurium PT other than DT104 may limit the use of resistance gene markers in its detection methods by PCR.
authors.affiliation: Department of Infectious Disease, College of Veterinary Medicine, KRF Zoonotic Disease Priority Research Institute and Brain Korea 21 for Veterinary Science, Seoul National University, Seoul, Korea.
authors.forename: Nabin
authors.initials: N
authors.lastname: Rayamajhi
authors.forename: Sang Gyun
authors.initials: SG
authors.lastname: Kang
authors.forename: Mi Lan
authors.initials: ML
authors.lastname: Kang
authors.forename: Hee Soo
authors.initials: HS
authors.lastname: Lee
authors.forename: Kyung Yoon
authors.initials: KY
authors.lastname: Park
authors.forename: Han Sang
authors.initials: HS
authors.lastname: Yoo
mesh_terms: D000818:Animals; D001434:Bacteriophage Typing / Q000662:veterinary; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D032023:Integrons / Q000235:genetics; D007723:Korea / Q000453:epidemiology; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D016133:Polymerase Chain Reaction / Q000662:veterinary; D015995:Prevalence; D012481:Salmonella Infections, Animal / Q000453:epidemiology / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial