title: Characterization of plasmid-mediated quinolone resistance determinants in Klebsiella pneumoniae and Escherichia coli from Tokai, Japan.
abstract: The spread of plasmid-mediated quinolone resistance (PMQR) determinants was evaluated in 150 ceftazidime or cefotaxime-resistant clinical isolates of Klebsiella pneumoniae and Escherichia coli from Tokai, Japan between 2008 and 2011. In this study, qnrB, qnrS, and aac(6')-Ib-cr genes were detected in 12 (50.0%), 4 (16.7%), and 1 (4.2%) of 24 K. pneumoniae isolates, respectively, while qnrA, aac(6')-Ib-cr, and qepA genes were detected in 1 (0.8%), 11 (8.7%), and 2 (1.6%) of 126 E. coli isolates, respectively. qnr genes were mainly found in K. pneumoniae (66.7%) and to a lesser extent in E. coli (0.8%). We determined the genetic environment of the qnrB4 gene in 24.6 kb class 1 integron structure, including aar-2, cmlA, blaOXA-10, aadA1, qacEdelta1, sul1, and blaDHA-1. In a time-kill assay, introduction of the qnrB4 or qnrS1 plasmid to the recipient E. coli strain decreased the bactericidal activities of fluoroquinolones such as ciprofloxacin, levofloxacin, and pazufloxacin.
authors.affiliation: Department of Clinical Infectious Diseases, Aichi Medical University Graduate School of Medicine, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan; Research Laboratories, Toyama Chemical Co., Ltd., 2-4-1 Shimookui, Toyama 930-8508, Japan. Electronic address: hayato_okade@toyama-chemical.co.jp.
authors.forename: Hayato
authors.initials: H
authors.lastname: Okade
authors.affiliation: Research Laboratories, Toyama Chemical Co., Ltd., 2-4-1 Shimookui, Toyama 930-8508, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakagawa
authors.affiliation: Research Laboratories, Toyama Chemical Co., Ltd., 2-4-1 Shimookui, Toyama 930-8508, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Sakagami
authors.affiliation: Research Laboratories, Toyama Chemical Co., Ltd., 2-4-1 Shimookui, Toyama 930-8508, Japan.
authors.forename: Harumi
authors.initials: H
authors.lastname: Hisada
authors.affiliation: Research Laboratories, Toyama Chemical Co., Ltd., 2-4-1 Shimookui, Toyama 930-8508, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Nomura
authors.affiliation: Development Division, Toyama Chemical Co., Ltd., 3-2-5 Nishishinjyuku, Shinjyuku-ku, Tokyo 160-0023, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Mitsuyama
authors.affiliation: Department of Clinical Infectious Diseases, Aichi Medical University Hospital, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Yamagishi
authors.affiliation: Department of Clinical Infectious Diseases, Aichi Medical University Graduate School of Medicine, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan; Department of Clinical Infectious Diseases, Aichi Medical University Hospital, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan.
authors.forename: Hiroshige
authors.initials: H
authors.lastname: Mikamo
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics*; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics*; D010957:Plasmids / Q000235:genetics; D015995:Prevalence; D015363:Quinolones / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D015363:Quinolones
keywords: Bactericidal activity; Klebsiella pneumoniae; Plasmid-mediated quinolone resistance; qnr