2nd Affiliated Hospital of Zhejiang University, Zhejiang University, Hangzhou, People's Republic of China.
Antimicrob Agents Chemother. 2014;58(2):1146-52. doi: 10.1128/AAC.00912-13. Epub 2013 Dec 9.
Twenty-two KPC-2-producing Escherichia coli isolates were obtained from three hospitals in Hangzhou, China, from 2007 to 2011. One isolate, with OmpC porin deficiency, exhibited high-level carbapenem resistance. Pulsed-field gel electrophoresis showed that few isolates were indistinguishable or closely related. Multilocus sequence typing indicated that sequence type 131 (ST131) was the predominant type (9 isolates, 40.9%), followed by ST648 (5 isolates), ST405 (2 isolates), ST38 (2 isolates), and 4 single STs, ST69, ST2003, ST2179, and ST744. Phylogenetic analysis indicated that 9 group B2 isolates belonged to ST131, and 5 of 11 group D isolates belonged to ST648. Only one group B1 isolate and one group A isolate were identified. A representative plasmid (pE1) was partially sequenced, and a 7,788-bp DNA fragment encoding Tn3 transposase, Tn3 resolvase, ISKpn8 transposase, KPC-2, and ISKpn6-like transposase was obtained. The blaKPC-2-surrounding sequence was amplified by a series of primers. The PCR results showed that 13 isolates were consistent with the genetic environment in pE1. It is the first report of rapid emergence of KPC-2-producing E. coli ST131 in China. The blaKPC-2 gene of most isolates was located on a similar genetic structure.
2007 年至 2011 年，从中国杭州的三家医院中分离到 22 株产 KPC-2 的大肠杆菌。其中一个分离株 OmpC 孔蛋白缺失，表现出高水平的碳青霉烯类耐药性。脉冲场凝胶电泳显示，少数分离株无法区分或密切相关。多位点序列分型表明，主要型别为 131 型（9 株，占 40.9%），其次是 648 型（5 株）、405 型（2 株）、38 型（2 株）和 4 个单型别，69 型、2003 型、2179 型和 744 型。系统进化分析表明，9 株 B2 组分离株属于 131 型，11 株 D 组分离株中有 5 株属于 648 型。只鉴定出 1 株 B1 组和 1 株 A 组分离株。部分测序了一个代表性质粒（pE1），获得了一个编码 Tn3 转座酶、Tn3 解旋酶、ISKpn8 转座酶、KPC-2 和 ISKpn6 样转座酶的 7788bp DNA 片段。通过一系列引物扩增 blaKPC-2 周围序列。PCR 结果表明，13 株分离株与 pE1 中的遗传环境一致。这是中国首例快速出现的产 KPC-2 的大肠杆菌 131 型。大多数分离株的 blaKPC-2 基因位于类似的遗传结构上。
