title: Resistance phenotypes and genotypes among multiple-antimicrobial-resistant Salmonella enterica subspecies enterica serovar Choleraesuis strains isolated between 2008 and 2012 from slaughter pigs in Okinawa Prefecture, Japan.
abstract: A total of 349 Salmonella enterica subspecies enterica serovar Choleraesuis (S. Choleraesuis) strains, which were isolated between 2008 and 2012 from 349 pigs at two slaughterhouses in Okinawa Prefecture, Japan, were investigated for antimicrobial susceptibility and the presence of antimicrobial resistance genes. All isolates were resistant to at least four antimicrobial agents. The antimicrobial agents for which isolates showed a high incidence of resistance were as follows: ampicillin (100%) and streptomycin (100%), followed by gentamicin (99.7%), oxytetracycline (99.7%), sulfamethoxazole/trimethoprim (99.4%), nalidixic acid (40.1%) and oxolinic acid (40.1%). All isolates were sensitive to cefuroxime, ceftiofur, colistin, fosfomycin, enrofloxacin, orbifloxacin and danofloxacin. The predominant resistance phenotypes and genotypes were: resistance to ampicillin, streptomycin, gentamicin, oxytetracycline and sulfamethoxazole/trimethoprim (58.5%, 204/349) and blaTEM-strA-strB-aadA1-aadA2-aacC2-tet (B)-sul1-sul2-dhfrXII-dhfrXIII (36.1%, 126/349). The quinolone resistance-determining regions (QRDRs) of gyrA, gyrB, parC and parE of the quinolone-resistant isolates (n=12) showed amino acid substitutions of Ser-83→Phe or Asp-87→Tyr in GyrA and Ser-107→Ala in ParC. To our knowledge, this is the first report on the molecular characterization of antimicrobial resistance among S. Choleraesuis strains in Japan.
authors.affiliation: Okinawa Prefecture Central Livestock Hygiene Service Center, 2505 Ozato, Ozato, Nanjyo, Okinawa 901-1202, Japan.
authors.forename: Masanao
authors.initials: M
authors.lastname: Matayoshi
authors.forename: Takashi
authors.initials: T
authors.lastname: Kitano
authors.forename: Tetsu
authors.initials: T
authors.lastname: Sasaki
authors.forename: Masaji
authors.initials: M
authors.lastname: Nakamura
mesh_terms: D000003:Abattoirs / Q000592:standards; D000667:Ampicillin; D000818:Animals; D001483:Base Sequence; D027081:DNA Gyrase / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D027101:DNA Topoisomerase IV / Q000235:genetics; D004352:Drug Resistance, Microbial / Q000235:genetics* / Q000502:physiology; D005798:Genes, Bacterial / Q000235:genetics*; D005838:Genotype; D005839:Gentamicins; D062312:Islands / Q000453:epidemiology; D007564:Japan / Q000453:epidemiology; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D008969:Molecular Sequence Data; D009268:Nalidixic Acid; D010093:Oxolinic Acid; D010118:Oxytetracycline; D010641:Phenotype; D019779:Salmonella enterica / Q000235:genetics* / Q000502:physiology; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013307:Streptomycin; D013420:Sulfamethoxazole; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology* / Q000382:microbiology*
chemical_list: D017931:DNA Primers; D005839:Gentamicins; D009268:Nalidixic Acid; D000667:Ampicillin; D027101:DNA Topoisomerase IV; D027081:DNA Gyrase; D013420:Sulfamethoxazole; D010093:Oxolinic Acid; D010118:Oxytetracycline; D013307:Streptomycin