Emerg Infect Dis. 2022 Jul;28(7):1421-1430. doi: 10.3201/eid2807.212181.
Carbapenem-resistant Enterobacterales (CRE) infection is highly endemic in China; Klebsiella pneumoniae carbapenemase (KPC) 2-producing CRE is the most common, whereas KPC-3-producing CRE is rare. We report an outbreak of KPC-3-producing Enterobacterales infection in China. During August 2020-June 2021, 25 bla-positive Enterobacteriale isolates were detected from 24 patients in China. Whole-genome sequencing analysis revealed that the bla genes were harbored by IncX8 plasmids. The outbreak involved clonal expansion of KPC-3-producing Serratia marcescens and transmission of bla plasmids across different species. The bla plasmids demonstrated high conjugation frequencies (10 to 10). A Galleria mellonella infection model showed that 2 sequence type 65 K2 K. pneumoniae strains containing bla plasmids were highly virulent. A ceftazidime/avibactam in vitro selection assay indicated that the KPC-3-producing strains can readily develop resistance. The spread of bla-harboring IncX8 plasmids and these KPC-3 strains should be closely monitored in China and globally.
产碳青霉烯酶肠杆菌科（CRE）感染在中国高度流行；产肺炎克雷伯菌碳青霉烯酶（KPC）2 的 CRE 最为常见，而产 KPC-3 的 CRE 则较为罕见。我们报告了中国一起产 KPC-3 的肠杆菌科感染的暴发事件。2020 年 8 月至 2021 年 6 月期间，中国 24 名患者的 25 株 bla 阳性肠杆菌科分离株被检测到。全基因组测序分析显示，bla 基因由 IncX8 质粒携带。此次暴发涉及产 KPC-3 的黏质沙雷氏菌的克隆扩张以及 bla 质粒在不同种属之间的传播。bla 质粒表现出较高的接合频率（10 到 10）。金龟子幼虫感染模型表明，2 株携带 bla 质粒的 65 型 K2 肺炎克雷伯菌菌株具有高度的毒力。头孢他啶/阿维巴坦体外选择试验表明，产 KPC-3 的菌株很容易产生耐药性。在中国和全球范围内，应密切监测携带 bla 的 IncX8 质粒和这些 KPC-3 菌株的传播。
