Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University Medical College, Tainan, Taiwan.
Microb Drug Resist. 2011 Jun;17(2):259-66. doi: 10.1089/mdr.2010.0115. Epub 2011 Feb 25.
This study was conducted to investigate the prevalence and characteristics of ertapenem-resistant (ETP-R) Klebsiella pneumoniae isolates at a Taiwanese hospital. The disk-diffusion tests revealed that the rate of ertapenem resistance among all isolates collected in 2008 was 13.5%, and the resistance rate among bloodstream isolates increased from 0% to 13.6% between 2001 and 2008. Eighty-two nonduplicate ETP-R isolates collected in 2008 were examined. Seventy-four (90.2%) isolates of them had extended-spectrum β-lactamases (CTX-M- and SHV-type), AmpC enzymes (DHA-1 and CMY-2), and IMP-8 metallo-β-lactamase alone or in combination, and an extremely high prevalence of fluoroquinolone resistance (95.1%) and plasmid-mediated quinolone resistance determinants (90.2%) were also observed. Eighteen ETP-R but imipenem-susceptible isolates were selected and compared with 18 imipenem-nonsusceptible isolates collected before 2008. Sequence analyses revealed genetic disruptions of OmpK36 in 11 imipenem-nonsusceptible and 6 imipenem-susceptible isolates, respectively, and OmpK35 disruptions in 10 isolates for both groups. For the isolates with intact ompK36, sodium dodecyl sulfate-polyacrylamide gel electrophoresis suggests decreased expression of OmpK36 in 5 of 7 imipenem-nonsusceptible isolates and 3 of 12 imipenem-susceptible isolates. In conclusion, the increasing prevalence of ertapenem resistance that was predominantly attributed to noncarbapenemase-mediated resistance mechanisms in K. pneumoniae is becoming a serious treat to patients in Taiwan.
这项研究旨在调查台湾一家医院耐厄他培南（ertapenem）的肺炎克雷伯菌（Klebsiella pneumoniae）分离株的流行率和特征。纸片扩散试验显示，2008 年所有分离株的厄他培南耐药率为 13.5%，2001 年至 2008 年间血流感染分离株的耐药率从 0%增加到 13.6%。检测了 2008 年收集的 82 份非重复耐厄他培南分离株。其中 74 株（90.2%）分离株单独或联合产生超广谱β-内酰胺酶（CTX-M 和 SHV 型）、AmpC 酶（DHA-1 和 CMY-2）和 IMP-8 金属β-内酰胺酶，同时也观察到极高的氟喹诺酮耐药率（95.1%）和质粒介导的喹诺酮耐药决定因素（90.2%）。选择了 18 株耐厄他培南但对亚胺培南敏感的分离株，并与 2008 年前收集的 18 株对亚胺培南不敏感的分离株进行比较。序列分析显示，11 株对亚胺培南不敏感和 6 株对亚胺培南敏感的分离株分别存在 OmpK36 的基因缺失，两组各有 10 株分离株存在 OmpK35 的缺失。对于 OmpK36 完整的分离株，十二烷基硫酸钠-聚丙烯酰胺凝胶电泳显示 7 株对亚胺培南不敏感的分离株中有 5 株和 12 株对亚胺培南敏感的分离株中有 3 株 OmpK36 的表达减少。总之，耐厄他培南的流行率不断上升，主要归因于肺炎克雷伯菌中非碳青霉烯酶介导的耐药机制，这对台湾的患者构成了严重威胁。
