Molecular epidemiology of KPC-producing Klebsiella pneumoniae from invasive infections in Italy: increasing diversity with predominance of the ST512 clade II sublineage
Molecular epidemiology of KPC-producing Klebsiella pneumoniae from invasive infections in Italy: increasing diversity with predominance of the ST512 clade II sublineage
复制标题
DOI：
10.1093/jac/dkw337
复制
发表时间：
2016-12-01
影响因子：
5.2
通讯作者：
Pantosti, Annalisa
中科院分区：
文献类型：
--
作者：
Conte, Viola;Monaco, Monica;Pantosti, Annalisa
目的：耐碳青霉烯类肠杆菌科细菌(CRE)的流行是世界范围内临床医学最令人担忧的问题之一。在意大利，抗生素耐药性监测网络与意大利临床微生物学家协会抗菌剂委员会合作，推动了一项研究，以调查最近收集的碳青霉烯类耐药肺炎克雷伯菌(CR-KP)的耐碳青霉烯机制、克隆性和衣壳分型。方法：分布在意大利的17个实验室收集了两个不同研究期间(2011-12和2013)从侵袭性感染中分离的所有连续的非复制CR-KP。筛选杂交法寻找碳青霉烯酶基因，并经聚合酶链式反应和测序证实。对产KPC肺炎克雷伯菌(KPC-KP)进行PFGE和MLST分型。结果：收集的461株肺炎克雷伯菌中，CR-Kp占36.2%(n=167)。大多数(97%)的CR-KP对bla(Kpc)基因呈阳性。在KPC-KP群体中，检测到9个不同的STS，其中大多数分离物(94%)属于克隆群(CG)258。属于ST512的一个亚群显示相同的PFGE图谱，代表了大多数(57%)KPC-KP菌株，并在全国范围内分布。衣壳鉴定以wzi154、cps-2型为主(占CG258株的88.8%)。ST258株同时与CPS-1和CPS-2两种囊型相关，而ST512只与CPS-2相关。结论：虽然意大利KPC-KP有多克隆进化的趋势，但本研究表明KPC-KP群体基本上仍是寡克隆，携带CPS-2囊型的ST512谱系广泛扩散并产生KPC-3酶。
Objectives: The spread of carbapenem-resistant Enterobacteriaceae (CRE) represents one of the most worrisome problems for clinical medicine worldwide. In Italy, the Antibiotic-Resistance-Istituto Superiore di Sanita surveillance network, in collaboration with the Committee for Antimicrobial Agents of the Italian Society of Clinical Microbiologists, promoted a study to investigate the carbapenem-resistance mechanisms, clonal relatedness and capsular typing of a recent collection of carbapenem-resistant Klebsiella pneumoniae (CR-KP).Methods: A total of 17 laboratories distributed across Italy collected all consecutive non-replicate CR-KP isolated from invasive infections during two different study periods (2011-12 and 2013). Carbapenemase genes were searched for by filter hybridization and confirmed by PCR and sequencing. KPC-producing K. pneumoniae (KPC-KP) were typed by PFGE and MLST. Capsular types were identified by wzi gene typing.Results: Of the collected K. pneumoniae isolates (n = 461), the overall proportion of CR-KP was 36.2% (n = 167). The majority (97%) of the CR-KP were positive for the bla(KPC) gene. Among the KPC-KP population, nine different STs were detected with the majority of isolates (94%) belonging to the clonal group (CG) 258. A subpopulation that belonged to ST512 and showed an identical PFGE profile represented the majority (57%) of KPC-KP strains, with a countrywide distribution. Capsular characterization showed the predominance of the wzi154, cps-2 capsular type (88.8% of all CG258 strains). ST258 strains were associated with both cps-1 and cps-2 capsular types, while ST512 was associated with cps-2 only.Conclusions: Although a trend to a polyclonal evolution of the Italian KPC-KP was noted, this study showed that the KPC-KP population remained largely oligoclonal with the wide diffusion of an ST512 lineage carrying cps-2 capsular type and producing the KPC-3 enzyme.