title: Prevalence and characterization of Salmonella in pigs from conventional and organic farms and first report of S. serovar 1,4,[5],12:i:- from Korea.
abstract: This study compared the prevalence of Salmonella spp. and their antimicrobial susceptibilities in pigs from conventional and organic farms during 2012-2013 in Korea and characterized them by molecular methods. Altogether, 100 nontyphoid Salmonella were isolated: 47 from 1324 pigs (3.5%) from conventional farms and 53 from 641 pigs (8.3%) from organic farms. The most frequent serovar was Typhimurium (49%) followed by Panama (24%), 1,4,[5],12:i:- (5%), and Virchow (5%). Overall, the isolates were most often resistant to tetracycline (75%) followed by ampicillin (66%), streptomycin (57%), and gentamicin (44%). The prevalence of antimicrobial resistance, multi-drug resistance phenotype, and resistance to tetracycline, ampicillin, and gentamicin were significantly higher in swine Salmonella from conventional farms than those from organic farms. The most common resistance pattern was ampicillin-gentamicin-tetracycline (n=16). All eight ceftiofur-resistant Salmonella identified produced CTX-M-15. Overall, decreased susceptibility to ciprofloxacin was observed in 39 isolates. Among them, a single isolate was positive for qnrS1 gene. An insertion sequence ISEcp1 was detected upstream of blaCTX-M gene in all isolates. The spread of blaCTX-M-15 gene was attributed to combination of clonal expansion and horizontal dissemination mediated by IncHI2 plasmid. Multilocus variable number of tandem repeats analysis demonstrated clonal dissemination of S. Typhimurium and S. 1,4,[5],12:i:- strains in pigs. To our knowledge, this is the first report of blaCTX-M-15 gene in S. Virchow from pigs and qnrS1 gene in S. Rissen from animals. This study also reports the first occurrence of Salmonella serovar 1,4,[5],12:i:- from Korea and CTX-M-15 producing Salmonella from pigs in Korea.
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Manan-gu, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Migma Dorji
authors.initials: MD
authors.lastname: Tamang
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Manan-gu, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Mamata
authors.initials: M
authors.lastname: Gurung
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Manan-gu, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Hyang-Mi
authors.initials: HM
authors.lastname: Nam
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Manan-gu, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Dong Chan
authors.initials: DC
authors.lastname: Moon
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Manan-gu, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Su-Ran
authors.initials: SR
authors.lastname: Kim
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Manan-gu, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Geum-Chan
authors.initials: GC
authors.lastname: Jang
authors.affiliation: Jeollanamdo Livestock Sanitation Office Western Branch, 395 Miljae-ro, Myoryang-myeon, Yeonggwan-gun, Jeollanamdo 513-822, Republic of Korea.
authors.forename: Dae-Yeong
authors.initials: DY
authors.lastname: Jung
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Manan-gu, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Suk-Chan
authors.initials: SC
authors.lastname: Jung
authors.affiliation: Department of Microbiology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors.forename: Yong-Ho
authors.initials: YH
authors.lastname: Park
authors.affiliation: Bacterial Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Manan-gu, Anyang, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Suk-Kyung
authors.initials: SK
authors.lastname: Lim
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D058871:Organic Agriculture / Q000592:standards; D010957:Plasmids / Q000235:genetics; D015995:Prevalence; D056910:Republic of Korea / Q000453:epidemiology; D012481:Salmonella Infections, Animal / Q000453:epidemiology*; D065288:Serogroup; D013045:Species Specificity; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology* / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents
keywords: Extended-spectrum β-lactamase; MLVA; Nontyphoid Salmonella; Pigs; qnrS gene