Molecular epidemiology of carbapenem resistant Enterobacteriaceae in Valle d'Aosta region, Italy, shows the emergence of KPC-2 producing Klebsiella pneumoniae clonal complex 101 (ST101 and ST1789).
Molecular epidemiology of carbapenem resistant Enterobacteriaceae in Valle d'Aosta region, Italy, shows the emergence of KPC-2 producing Klebsiella pneumoniae clonal complex 101 (ST101 and ST1789).
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DOI：
10.1186/s12866-015-0597-z
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发表时间：
2015-11-09
期刊：
影响因子：
4.2
通讯作者：
Zarrilli R
中科院分区：
文献类型：
--
作者：
Del Franco M;Paone L;Novati R;Giacomazzi CG;Bagattini M;Galotto C;Montanera PG;Triassi M;Zarrilli R
碳青霉烯耐药肠杆菌科（CRE）的传播是一个新兴的临床问题，在欧洲和世界范围内具有重要意义。本研究的目的是意大利瓦莱达奥斯塔地区CRE分离株的分子流行病学和碳青霉烯类耐药机制。从2013年11月至2014年8月的52名住院患者和/或门诊患者中分离出60份连续CRE样本。采用脉冲场凝胶电泳（PFGE）和多位点序列分型（MLST）对分离菌株进行基因分型，采用PCR和测序法对碳青霉烯酶进行鉴定。通过过滤交配进行碳青霉烯类抗生素耐药基因转移，通过PCR复制子分型将亲本菌株和转移接合子菌株的质粒分配到不相容组。CRE分离株的分子表征将25株肺炎克雷伯菌分离株分配为PFGE A1-A5型和测序型（ST）101，17 K。pneumoniae分离株与A型PFGE和ST 1789（ST 101的单位点变异体）的同源性为7.3%。pneumoniae分离株与PFGE B或C型及ST 512、2 K. 5株大肠埃希菌为A型和ST 131型。所有K。肺炎克雷伯菌ST 101和ST 1789为产超广谱β-内酰胺酶（ESBL）菌株，携带blaCTX-M-1群基因; pneumoniae ST 101分离株对粘菌素耐药。β-内酰胺酶基因的分子分析将blaKPC-2和blaCTX-M-组1鉴定为接合质粒，分配给ST 101和ST 1789 K中的IncFII不相容组。pneumoniae分离株将blaKPC-3插入接合质粒中，在ST 512和ST 405 K中分配到IncF不相容性组。pneumoniae分离株将blaVIM-1插入到接合质粒中，分配到ST 131 E中的IncN不相容性组。大肠杆菌分离株。CRE在瓦莱达奥斯塔地区的传播是由于KPC-2产生K的选择引起的。pneumoniae ST 101和ST 1789流行性克隆属于克隆复合物101; pneumoniae流行性克隆，分配给ST 512和ST 405，以及产生Vim-1的大肠杆菌ST 131流行性克隆。碳青霉烯类耐药性，沿着blaKPC-2、blaKPC-3和blaVIM-1碳青霉烯酶基因，在滤器交配实验中分别通过分配至IncFII、IncF和IncN不相容性组的接合质粒转移。产K. pneumoniae ST 101分离株。本文的在线版本（doi：10.1186/s12866-015-0597-z）包含补充材料，可供授权用户使用。
The spread of carbapenem resistant Enterobacteriaceae (CRE) is an emerging clinical problem, of great relevance in Europe and worldwide. The aim of this study was the molecular epidemiology of CRE isolates in Valle d’Aosta region, Italy, and the mechanism of carbapenem resistance. Sixty consecutive CRE samples were isolated from 52 hospital inpatients and/or outpatients from November 2013 to August 2014. Genotyping of microbial isolates was done by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST), carbapenemases were identified by PCR and sequencing. Carbapenem resistance gene transfer was performed by filter mating, plasmids from parental and transconjugant strains were assigned to incompatibility groups by PCR-based replicon typing. Molecular characterization of CRE isolates assigned 25 Klebsiella pneumoniae isolates to PFGE types A1-A5 and sequencing type (ST) 101, 17 K. pneumoniae isolates to PFGE type A and ST1789 (a single locus variant of ST101), 7 K. pneumoniae isolates to PFGE types B or C and ST512, 2 K. pneumoniae isolates to PFGE type D and ST405, and 5 Escherichia coli isolates to PFGE type a and ST131. All K. pneumoniae ST101 and ST1789 isolates were extended-spectrum beta-lactamase (ESBL) producers and carried blaCTX-M-1 group gene; 4 K. pneumoniae ST101 isolates were resistant to colistin. Molecular analysis of beta-lactamase genes identified blaKPC-2 and blaCTX-M-group 1 into conjugative plasmid/s assigned to IncFII incompatibility group in ST101 and ST1789 K. pneumoniae isolates, blaKPC-3 into conjugative plasmid/s assigned to IncF incompatibility group in ST512 and ST405 K. pneumoniae isolates, blaVIM-1 into conjugative plasmid/s assigned to IncN incompatibility group in ST131 E. coli isolates. The spread of CRE in Valle d’Aosta region was caused by the selection of KPC-2 producing K. pneumoniae ST101 and ST1789 epidemic clones belonging to clonal complex 101, KPC-3 producing K. pneumoniae epidemic clones assigned to ST512 and ST405, and VIM-1 producing E.coli ST131 epidemic clone. Carbapenem resistance, along with blaKPC-2, blaKPC-3 and blaVIM-1 carbapenemase genes, was transferred by conjugative plasmids assigned to IncFII, IncF, and IncN incompatibility groups, respectively, in filter mating experiments. The emergence of colistin resistance was observed in KPC-2 producing K. pneumoniae ST101 isolates. The online version of this article (doi:10.1186/s12866-015-0597-z) contains supplementary material, which is available to authorized users.