Molecular characteristics of extended-spectrum beta-lactamases and qnr determinants in Enterobacter species from Japan |
| |
Authors: | Kanamori Hajime Yano Hisakazu Hirakata Yoichi Hirotani Ayako Arai Kazuaki Endo Shiro Ichimura Sadahiro Ogawa Miho Shimojima Masahiro Aoyagi Tetsuji Hatta Masumitsu Yamada Mitsuhiro Gu Yoshiaki Tokuda Koichi Kunishima Hiroyuki Kitagawa Miho Kaku Mitsuo |
| |
Institution: | Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan. kanamori@med.tohoku.ac.jp |
| |
Abstract: | The incidence of extended-spectrum β-lactamases (ESBLs) has been increasing worldwide, but screening criteria for detection of ESBLs are not standardized for AmpC-producing Enterobacteriaceae such as Enterobacter species. In this study, we investigated the prevalence of ESBLs and/or AmpC β-lactamases in Japanese clinical isolates of Enterobacter spp. and the association of plasmid-mediated quinolone resistance (PMQR) determinants with ESBL producers. A total of 364 clinical isolates of Enterobacter spp. collected throughout Japan between November 2009 and January 2010 were studied. ESBL-producing strains were assessed by the CLSI confirmatory test and the boronic acid disk test. PCR and sequencing were performed to detect CTX-M, TEM, and SHV type ESBLs and PMQR determinants. For ESBL-producing Enterobacter spp., pulsed-field gel electrophoresis (PFGE) was performed using XbaI restriction enzyme. Of the 364 isolates, 22 (6.0%) were ESBL producers. Seven isolates of Enterobacter cloacae produced CTX-M-3, followed by two isolates producing SHV-12. Two isolates of Enterobacter aerogenes produced CTX-M-2. Of the 22 ESBL producers, 21 had the AmpC enzyme, and six met the criteria for ESBL production in the boronic acid test. We found a significant association of qnrS with CTX-M-3-producing E. cloacae. The 11 ESBL-producing Enterobacter spp. possessing bla(CTX-M), bla(SHV), or bla(TEM) were divided into six unique PFGE types. This is the first report about the prevalence of qnr determinants among ESBL-producing Enterobacter spp. from Japan. Our results suggest that ESBL-producing Enterobacter spp. with qnr determinants are spreading in Japan. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|