Savov Encho, Politi Lida, Spanakis Nicholas, Trifonova Angelina, Kioseva Elena, Tsakris Athanasios
1 Laboratory of Microbiology , Military Medical Academy, Sofia, Bulgaria .
2 Department of Microbiology, Medical School, University of Athens , Athens, Greece .
Microb Drug Resist. 2018 Apr;24(3):253-259. doi: 10.1089/mdr.2017.0230. Epub 2017 Sep 6.
New Delhi MBL (NDM) carbapenemase-producing Klebsiella pneumoniae has become one of the most concerning multidrug-resistant pathogens. The Balkan counties are considered a reservoir for the spread of such strains based on several reports documenting NDM infections after hospitalization in this region. Nevertheless, NDM-producing K. pneumoniae have been only occasionally documented from Balkans. The current study documents the first polyclonal outbreak caused by NDM-1-producing K. pneumoniae in Bulgaria. From July 2015 to April 2016, all 25 single-patient carbapenem-nonsusceptible K. pneumoniae isolates were collected. Phenotypic and molecular screening revealed that 17 produced NDM-1 carbapenemase. All NDM-1 producers harbored bla, bla, bla, and bla; five also harbored bla. In all cases, bla was flanked upstream by ISAba125 element and downstream by ble. Pulsed-field gel electrophoresis (PFGE) clustered NDM-1-positive isolates into four distinct clonal types, A to D. MLST assigned isolates of the dominant clonal type A (n = 14) to sequence type (ST) 11, while isolates of clonal types B, C, and D to ST16, ST15, and ST391, respectively. Of interest, ST11 isolates belonged to the same PFGE type as those of the recently described NDM-1 ST11 clonal outbreak in Greece. Traveling abroad or overseas hospitalization was not reported in any case, suggesting most likely intra- and interhospital dissemination. The study presents the first polyclonal outbreak of NDM-producing K. pneumoniae in the Balkans and underlines the need for larger epidemiological studies in the region to illustrate commonalities in the transmission of NDM clones and possible sources in the community.
产新德里金属β-内酰胺酶（NDM）的肺炎克雷伯菌已成为最令人担忧的多重耐药病原体之一。基于该地区数份记录住院后NDM感染情况的报告，巴尔干半岛国家被视为此类菌株传播的一个储存库。尽管如此，产NDM的肺炎克雷伯菌在巴尔干地区仅偶尔有记录。本研究记录了保加利亚首次由产NDM-1的肺炎克雷伯菌引起的多克隆暴发。2015年7月至2016年4月，收集了所有25株对碳青霉烯类不敏感的单株肺炎克雷伯菌分离株。表型和分子筛查显示，17株产生NDM-1碳青霉烯酶。所有产NDM-1的菌株均携带bla、bla、bla和bla；5株还携带bla。在所有病例中，bla上游侧翼为ISAba125元件，下游侧翼为ble。脉冲场凝胶电泳（PFGE）将NDM-1阳性分离株分为四个不同的克隆类型，A至D。多位点序列分型（MLST）将优势克隆类型A（n = 14）的分离株归为序列型（ST）11，而克隆类型B、C和D的分离株分别归为ST16、ST15和ST391。有趣的是，ST11分离株与希腊最近描述的NDM-1 ST11克隆暴发的分离株属于同一PFGE类型。所有病例均未报告有出国旅行或海外住院情况，提示很可能是医院内和医院间传播。该研究呈现了巴尔干地区首次产NDM的肺炎克雷伯菌多克隆暴发，并强调需要在该地区开展更大规模的流行病学研究，以阐明NDM克隆传播的共性以及社区中可能的来源。
