title: Mechanism of resistance and antibacterial susceptibility in extended-spectrum β-lactamase phenotype Klebsiella pneumoniae and Klebsiella oxytoca isolated between 2000 and 2010 in Japan.
abstract: Clinical isolates of Klebsiella pneumoniae and Klebsiella oxytoca collected from 20 Japanese medical facilities between 2000 and 2010 were analysed to evaluate the mechanisms of resistance and antibacterial susceptibilities to 14 antimicrobials. Overall, eight of 484 (1.6%) K. pneumoniae and 19 of 359 (5.3%) K. oxytoca were determined to be extended-spectrum β-lactamase (ESBL) phenotype isolates, and the identified ESBLs amongst the K. pneumoniae isolates were CTX-M-2, -3, -14 and -15, and SHV-12. In contrast, overproduction of chromosomal β-lactamase OXY-2, which was due to a distinct mutation at the - 10 promoter region of this gene, conferred the ESBL phenotype to all the K. oxytoca isolates except one. Based on the Clinical and Laboratory Standards Institute breakpoints, all the ESBL phenotype K. pneumoniae were susceptible to doripenem, flomoxef, moxalactam (latamoxef), cefmetazole and tazobactam/piperacillin, whereas the ESBL phenotype K. oxytoca were susceptible to ceftazidime and ceftibuten in addition to the above, with the exception of tazobactam/piperacillin. Amongst the oral antimicrobials, ceftibuten was relatively effective against both ESBL phenotype Klebsiella species compared with levofloxacin and amoxicillin/clavulanic acid.
authors: Infectious Diseases, Discovery Research Laboratory for Core Therapeutic Areas, Shionogi & Co. Ltd 3-1-1 Futaba-cho, Toyonaka, Osaka, 561-0825, Japan.
authors: Takafumi
authors: T
authors: Sato
authors: Infectious Diseases, Discovery Research Laboratory for Core Therapeutic Areas, Shionogi & Co. Ltd 3-1-1 Futaba-cho, Toyonaka, Osaka, 561-0825, Japan.
authors: Takafumi
authors: T
authors: Hara
authors: Infectious Diseases, Discovery Research Laboratory for Core Therapeutic Areas, Shionogi & Co. Ltd 3-1-1 Futaba-cho, Toyonaka, Osaka, 561-0825, Japan.
authors: Tsukasa
authors: T
authors: Horiyama
authors: Infectious Diseases, Discovery Research Laboratory for Core Therapeutic Areas, Shionogi & Co. Ltd 3-1-1 Futaba-cho, Toyonaka, Osaka, 561-0825, Japan.
authors: Sachi
authors: S
authors: Kanazawa
authors: Infectious Diseases, Discovery Research Laboratory for Core Therapeutic Areas, Shionogi & Co. Ltd 3-1-1 Futaba-cho, Toyonaka, Osaka, 561-0825, Japan.
authors: Takahiro
authors: T
authors: Yamaguchi
authors: Infectious Diseases, Discovery Research Laboratory for Core Therapeutic Areas, Shionogi & Co. Ltd 3-1-1 Futaba-cho, Toyonaka, Osaka, 561-0825, Japan.
authors: Hideki
authors: H
authors: Maki
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003428:Cross Infection / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D006801:Humans; D007564:Japan; D007710:Klebsiella Infections / Q000382:microbiology*; D041121:Klebsiella oxytoca / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000032:analysis / Q000235:genetics; D047090:beta-Lactams / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D047090:beta-Lactams; D001618:beta-Lactamases