1Department of Infectious Diseases, Nagoya University Hospital, 65 Tsurumai, Nagoya, Aichi 466-0065 Japan.
2Department of Infectious Diseases, Nagoya University Graduate School of Medicine, Nagoya, Aichi Japan.
Antimicrob Resist Infect Control. 2019 Jul 24;8:126. doi: 10.1186/s13756-019-0578-3. eCollection 2019.
To clarify the molecular epidemiology of carbapenem-resistant complex (CREC) and the risk factors for acquisition of carbapenemase-producing complex (CPEC).
Using clinical CREC isolates detected in a Japanese university hospital over 4 years, carbapenemase production was screened with phenotypic methods. Carbapenemase genes were analysed by PCR and sequencing. Molecular epidemiological analyses were conducted with repetitive extragenic palindromic (REP)-PCR and multilocus sequence typing (MLST). CRECs were identified to the subspecies level by sequencing. Whole-genome sequencing of plasmids was conducted. A case-control study was performed to identify risk factors for acquisition of CPEC among patients with CREC.
Thirty-nine CRECs including 20 CPECs carrying were identified. Patients with CPEC had longer hospital stay before detection (26.5 days vs. 12 days, = 0.008), a urinary catheter (odds ratio [OR], 5.36; 95% confidence interval [CI], 1.14-30.9; = 0.023), or intubation (OR, 7.53; 95% CI, 1.47-53.8; = 0.008) compared to patients without CPEC. Four genetically closely related CPEC clusters were observed, which showed that three of four CPEC clusters corresponded to (ST 53), subsp. (ST 113 and ST 1047) and subsp. (ST 513) by MLST and sequencing. Seven representative plasmids shared structures with class I integron containing and IncHI2A replicon type.
A longer hospital stay, presence of a urinary catheter, and intubation are risk factors for CPEC acquisition. In addition to horizontal transmission of genetically indistinguishable CPECs, IncHI2A plasmid carrying appeared to be transferred among genetically different ECs.
阐明耐碳青霉烯肠杆菌科（CREC）的分子流行病学以及获得产碳青霉烯酶肠杆菌科（CPEC）的危险因素。
使用 4 年来日本一家大学医院检测到的临床 CREC 分离株，采用表型方法筛选碳青霉烯酶的产生。通过 PCR 和测序分析碳青霉烯酶基因。采用重复回文外遗传（REP）-PCR 和多位点序列分型（MLST）进行分子流行病学分析。通过测序将 CREC 鉴定到亚种水平。对质粒进行全基因组测序。对携带 CREC 的患者进行病例对照研究，以确定获得 CPEC 的危险因素。
鉴定出 39 株 CREC，包括 20 株携带 的 CPEC。与未携带 CPEC 的患者相比，携带 CPEC 的患者在检测前的住院时间更长（26.5 天 vs. 12 天， = 0.008），有尿路导管（比值比 [OR]，5.36；95%置信区间 [CI]，1.14-30.9； = 0.023）或插管（OR，7.53；95% CI，1.47-53.8； = 0.008）。观察到四个遗传上密切相关的 CPEC 簇，通过 MLST 和 测序表明，四个 CPEC 簇中的三个分别对应于 （ST53）、 亚种 （ST113 和 ST1047）和 亚种 （ST513）。七个代表性质粒与包含 和 IncHI2A 复制子类型的 I 类整合子的结构共享。
较长的住院时间、存在尿路导管和插管是获得 CPEC 的危险因素。除了遗传上不可区分的 CPEC 的水平传播外，携带 的 IncHI2A 质粒似乎在遗传上不同的 EC 之间转移。
