Institute of Biomedical Informatics and Centre for Systems and Synthetic Biology, National Yang-Ming University, Taipei, Taiwan.
Institute of Emergency and Critical Care Medicine, National Yang-Ming University, Taipei, Taiwan.
J Antimicrob Chemother. 2018 Aug 1;73(8):2039-2046. doi: 10.1093/jac/dky164.
Carbapenemase-producing Klebsiella pneumoniae causes high mortality owing to the limited therapeutic options available. Here, we investigated an emergent carbapenem-resistant K. pneumoniae strain with hypervirulence found among KPC-2-producing strains in Taiwan.
KPC-producing K. pneumoniae strains were collected consecutively from clinical specimens at the Taipei Veterans General Hospital between January 2012 and December 2014. Capsular types and the presence of rmpA/rmpA2 were analysed, and PFGE and MLST performed using these strains. The strain positive for rmpA/rmpA2 was tested in an in vivo mouse lethality study to verify its virulence and subjected to WGS to delineate its genomic features.
A total of 62 KPC-2-producing K. pneumoniae strains were identified; all of these belonged to ST11 and capsular genotype K47. One strain isolated from a fatal case with intra-abdominal abscess (TVGHCRE225) harboured rmpA and rmpA2 genes. This strain was resistant to tigecycline and colistin, in addition to carbapenems, and did not belong to the major cluster in PFGE. TVGHCRE225 exhibited high in vivo virulence in the mouse lethality experiment. WGS showed that TVGHCRE225 acquired a novel hybrid virulence plasmid harbouring a set of virulence genes (iroBCDN, iucABCD, rmpA and rmpA2, and iutA) compared with the classic ST11 KPC-2-producing strain.
We identified an XDR ST11 KPC-2-producing K. pneumoniae strain carrying a hybrid virulent plasmid in Taiwan. Active surveillance focusing on carbapenem-resistant hypervirulent K. pneumoniae strains is necessary, as the threat to human health is imminent.
产碳青霉烯酶的肺炎克雷伯菌由于治疗选择有限，死亡率很高。在这里，我们研究了一种在台湾发现的产 KPC-2 的碳青霉烯耐药肺炎克雷伯菌中出现的具有高毒力的新兴碳青霉烯耐药菌株。
从 2012 年 1 月至 2014 年 12 月期间，连续从台北荣民总医院的临床标本中收集产 KPC 的肺炎克雷伯菌菌株。分析了荚膜类型和 rmpA/rmpA2 的存在情况，并对这些菌株进行 PFGE 和 MLST。对 rmpA/rmpA2 阳性的菌株进行体内小鼠致死性研究，以验证其毒力，并对其进行 WGS 以描绘其基因组特征。
共鉴定出 62 株产 KPC-2 的肺炎克雷伯菌；所有这些都属于 ST11 和荚膜基因型 K47。从一例伴有腹腔脓肿的致命病例中分离出的一株（TVGHCRE225）携带 rmpA 和 rmpA2 基因。该菌株对替加环素和多粘菌素耐药，除碳青霉烯类药物外，不属于 PFGE 的主要聚类。在小鼠致死性实验中，TVGHCRE225 表现出高体内毒力。WGS 显示，与经典的 ST11 产 KPC-2 菌株相比，TVGHCRE225 获得了一种新型的杂交毒力质粒，该质粒携带了一组毒力基因（iroBCDN、iucABCD、rmpA 和 rmpA2 以及 iutA）。
我们在台湾发现了一株携带杂交毒力质粒的 XDR ST11 产 KPC-2 的肺炎克雷伯菌。需要对碳青霉烯耐药高毒力肺炎克雷伯菌菌株进行主动监测，因为对人类健康的威胁迫在眉睫。
