KPC-2-encoding plasmids from Escherichia coli and Klebsiella pneumoniae in Taiwan
KPC-2-encoding plasmids from Escherichia coli and Klebsiella pneumoniae in Taiwan
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DOI：
10.1093/jac/dkt409
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发表时间：
2014-03-01
影响因子：
5.2
通讯作者：
Siu, L. Kristopher
中科院分区：
文献类型：
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作者：
Chen, Ying-Tsong;Lin, Jung-Chung;Siu, L. Kristopher
目的：对碳青霉烯耐药大肠杆菌（CR-EC）和碳青霉烯耐药肺炎克雷伯菌（CR-KP）中分别携带bla（KPC-2）的两个质粒进行完全测序。CR-KP菌株选自2012年的一次疫情，CR-EC菌株是台湾同一碳青霉烯类耐药性监测规划中首次发现的携带bla（KPC-2）的大肠杆菌。方法：进行药敏试验、多位点序列分型（MLST）和质粒偶联转移。质粒的完全测序使用散弹枪法进行。结果：本研究的CR-EC和CR-KP菌株经MLST鉴定分别为ST410和ST11。从CR-EC中，我们鉴定了一个145 kb的共轭质粒，该质粒携带bla（KPC-2）、bla（CMY-2）、bla（CTX-M-3）和bla（TEM-1）。质粒是由与IncI、IncN和RepFIC复制子相关的三个区域组成的嵌合体。从CR-KP中，我们鉴定出一个86.5 kb的质粒pKPC-LK30，它携带bla（KPC-2）和bla（SHV-11）。质粒与两个携带bla（KPC-2）的IncFII(K)质粒非常相似，但缺少一个复制起点，不能结合。结论：两种质粒在跨种可转移性上的差异可能与它们脊骨的遗传差异有关，这可能是导致台湾地区携带bla（KPC-2）的CR-KP有限暴发的原因。质粒pKPC-LKEc是台湾首次从CR-EC中鉴定到携带bla（KPC-2）的质粒。它具有较高的可转移性，应密切监测。
Objectives: Two plasmids carrying bla(KPC-2) isolated from carbapenem-resistant Escherichia coli (CR-EC) and carbapenem-resistant Klebsiella pneumoniae (CR-KP), respectively, were completely sequenced. The CR-KP strain was selected from an outbreak in 2012, and the CR-EC strain was the first bla(KPC-2)-carrying E. coli identified in the same carbapenem resistance monitoring programme in Taiwan.Methods: Antimicrobial susceptibility tests, multilocus sequence typing (MLST) and the conjugal transfer of plasmids were performed. Complete sequencing of the plasmids was performed using a shotgun approach.Results: The CR-EC and CR-KP strains in this study were determined to be ST410 and ST11, respectively, by MLST. From CR-EC, we identified a 145 kb conjugative plasmid that carries bla(KPC-2), bla(CMY-2), bla(CTX-M-3) and bla(TEM-1). The plasmid is a chimera composed of three regions related to IncI, IncN and RepFIC replicons. From CR-KP, we identified an 86.5 kb plasmid, pKPC-LK30, which carries bla(KPC-2) and bla(SHV-11). The plasmid is very similar to two bla(KPC-2)-carrying IncFII(K) plasmids, but lacks one of the replication origins and cannot conjugate.Conclusions: The differences in cross-species transferability of the two plasmids can be explained by genetic differences between their backbones and could have resulted in the confined bla(KPC-2)-carrying CR-KP outbreak in Taiwan. Plasmid pKPC-LKEc is the first bla(KPC-2)-carrying plasmid identified from CR-EC in Taiwan. With relatively high transferability it should be closely monitored.