Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
Department of Laboratory Medicine, The Second Hospital of Anhui Medical University, Hefei, Anhui, China.
Ann Lab Med. 2019 Mar;39(2):167-175. doi: 10.3343/alm.2019.39.2.167.
Carbapenem-resistant hypervirulent (hypermucoviscous) (CR-HMKP) poses a significant public health challenge. We investigated its epidemiology and molecular characteristics in a tertiary care hospital in eastern China.
CR-HMKP were identified among 106 non-duplicated carbapenem-resistant isolates (from June 2013 to September 2017) using the string test. The pulsotype (PT) and sequence type (ST) of CR-HMKP isolates were determined using pulsed-field gel electrophoresis and multilocus sequence typing. Resistance determinants, capsular serotypes, and virulence genes were detected by PCR and sequencing. Representative isolates from each PT were selected, and their virulence phenotypes were established using the serum killing and lethality assays.
Of the 106 isolates, 13 (12.3%) were CR-HMKP. Seven were positive for and shared the same genotype (PT5/ST1764); the others were positive for , belonged to ST11, and were divided into four different PTs. The serotype of all -positive isolates was K64, while that of -positive isolates were K47 (N=4) and K64 (N=2). The NDM-1-producing HMKP isolates were positive for , exhibited high serum resistance, and elicited significantly increased larval mortality compared with the other isolates. All patients had received invasive treatment prior to infection by NDM-1-producing HMKP. The infections occurred between July and August 2016 and were hospital-acquired.
NDM-1-producing HMKP ST1764 isolates were identified; this is the first report worldwide on an outbreak of nosocomial infection caused by these isolates. Effective surveillance and strict infection control strategies should be implemented to prevent CR-HMKP dissemination.
耐碳青霉烯高毒力（高黏液性）（CR-HMKP）对公共健康构成重大挑战。我们在中国东部的一家三级保健医院研究了其流行病学和分子特征。
采用.string 试验从 2013 年 6 月至 2017 年 9 月的 106 例非重复耐碳青霉烯分离株中鉴定出 CR-HMKP。通过脉冲场凝胶电泳和多位点序列分型确定 CR-HMKP 分离株的脉冲型（PT）和序列型（ST）。通过 PCR 和测序检测耐药决定因子、荚膜血清型和毒力基因。从每个 PT 中选择代表性分离株，并通过血清杀伤和致死性测定建立其毒力表型。
在 106 株分离株中，有 13 株（12.3%）为 CR-HMKP。其中 7 株为阳性，具有相同的基因型（PT5/ST1764）；其余 6 株为阳性，属于 ST11，分为 4 个不同的 PT。所有阳性分离株的血清型均为 K64，而阳性分离株的血清型分别为 K47（N=4）和 K64（N=2）。携带 NDM-1 的 HMKP 分离株对血清具有高抗性，并与其他分离株相比，引起幼虫死亡率显著增加。所有患者在感染携带 NDM-1 的 HMKP 之前均接受过侵入性治疗。感染发生在 2016 年 7 月至 8 月之间，为医院获得性感染。
鉴定出携带 NDM-1 的 HMKP ST1764 分离株；这是全球首次报告由这些分离株引起的医院感染爆发。应实施有效的监测和严格的感染控制策略，以防止 CR-HMKP 的传播。
