title: Contribution of multi-antimicrobial resistance to the population of antimicrobial resistant Escherichia coli isolated from apparently healthy pigs in Japan.
abstract: The aim of this study was to clarify the involvement of tetracycline usage in resistance rates against other antimicrobials. Antimicrobial susceptibility testing was carried out on 545 porcine Escherichia coli isolates throughout Japan. As the result of analyzing by regions, resistance rates against kanamycin, oxytetracycline and trimethoprim in the Kanto/Koshinetu district were higher than those in some other districts. High resistance rates against kanamycin or trimethoprim in oxytetracycline-resistant isolates were also observed in the Kanto/Koshinetu district. The prevalence of multi-antimicrobial resistance through co-selection of resistances against kanamycin or trimethoprim by tetracycline usage could be the cause of regional differences in these resistances in porcine E. coli. By a communicative surveillance, kanamycin- and trimethoprim-resistance rates were likely to be elevated with tetracycline usage. Thus, usage of specific antimicrobial(s) is a remarkable viewpoint to control antimicrobial resistant bacteria.
authors.affiliation: National Veterinary Assay Laboratory, Ministry of Agriculture, Forestry and Fisheries, Kukubunji, Tokyo 185-8511, Japan. kazuki_harada@nm.maff.go.jp
authors.forename: Kazuki
authors.initials: K
authors.lastname: Harada
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Asai
authors.forename: Akemi
authors.initials: A
authors.lastname: Kojima
authors.forename: Toshiya
authors.initials: T
authors.lastname: Sameshima
authors.forename: Toshio
authors.initials: T
authors.lastname: Takahashi
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D007564:Japan; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D013552:Swine / Q000382:microbiology*; D013753:Tetracycline Resistance
chemical_list: D000900:Anti-Bacterial Agents