■我们调查了住院患者耐碳青霉烯类肠杆菌(CRE)分离株的肠道定植和医院感染的流行病学监测,这可以为制定有效的预防措施提供依据。
■在2016年1月至2017年6月期间,共从1,487例住院儿童的粪便样本中收集了96株CRE菌株,这些样本被定义为“CRE定植”组。总的来说,还随机选择了70株CRE临床分离株进行比较分析,并将其定义为“CRE感染”组。通过微量稀释液法测定所有菌株的抗菌敏感性。聚合酶链反应(PCR)用于分析碳青霉烯酶基因,质粒分型,和积分。进一步使用多位点序列分型来确定克隆相关性。
■在“CRE定殖”组中,肺炎克雷伯菌检出率达42.7%(41/96),其次是大肠杆菌(34.4%,33/96)和阴沟肠杆菌(15.6%,15/96)。ST11KPC-2生产商,ST8NDM-5生产者,和ST45NDM-1生产者通常存在于耐碳青霉烯类肺炎克雷伯菌(CRKPN)中,耐碳青霉烯类大肠杆菌(CRECO),和耐碳青霉烯类阴沟肠杆菌(CRECL)分离株,分别。在“CRE感染”组中,70%(49/70)的菌株为肺炎克雷伯菌,有21.4%的阴沟肠杆菌(15/70)和5.7%的大肠杆菌(4/70)。在CRKPN分离株中经常观察到ST15OXA-232生产者和ST48NDM-5生产者,而大多数产生NDM-1的CRECL分离株被指定为ST45。系统发育分析显示部分CRE分离株肠道定植与医院感染密切相关,特别是ST11KPC-2生产CRKPN和ST45NDM-1生产CRECL。此外,质粒分型表明,IncF和IncFIB是KPC-2生产者中最普遍的质粒,而IncX3/IncX2和ColE在NDM生产商和OXA-232生产商中广泛传播,分别。然后,1类整合子整合酶intI1在“CRE定植”组的74.0%(71/96)和“CRE感染”组的52.9%(37/70)中呈阳性。
■这项研究表明,来自肠道定植和医院感染的CRE菌株在CRE的患病率中表现出部分相关性,特别是ST11KPC-2生产CRKPN和ST45NDM-1生产CRECL。因此,入院前,应强调CRE分离株直肠定植的长期积极筛查.
We investigated the epidemiological surveillance of the intestinal colonization and nosocomial infection of carbapenem-resistant Enterobacteriales (CRE) isolates from inpatients, which can provide the basis for developing effective prevention.
A total of 96 CRE strains were collected from 1,487 fecal samples of hospitalized children between January 2016 and June 2017, which were defined as the \"CRE colonization\" group. In total, 70 CRE clinical isolates were also randomly selected for the comparison analysis and defined as the \"CRE infection\" group. The antimicrobial susceptibility of all strains was determined by the microdilution broth method. Polymerase chain reaction (PCR) was used to analyze carbapenemase genes, plasmid typing, and integrons. Multilocus sequence typing was further used to determine clonal relatedness.
In the \"CRE colonization\" group, Klebsiella pneumoniae was mostly detected with a rate of 42.7% (41/96), followed by Escherichia coli (34.4%, 33/96) and Enterobacter cloacae (15.6%, 15/96). The ST11 KPC-2 producer, ST8 NDM-5 producer, and ST45 NDM-1 producer were commonly present in carbapenem-resistant K. pneumoniae (CRKPN), carbapenem-resistant E. coli (CRECO), and carbapenem-resistant E. cloacae (CRECL) isolates, respectively. In the \"CRE infection\" group, 70% (49/70) of strains were K. pneumoniae, with 21.4% E. cloacae (15/70) and 5.7% E. coli (4/70). The ST15 OXA-232 producer and ST48 NDM-5 producer were frequently observed in CRKPN isolates, while the majority of NDM-1-producing CRECL isolates were assigned as ST45. Phylogenetic analysis showed that partial CRE isolates from intestinal colonization and nosocomial infection were closely related, especially for ST11 KPC-2-producing CRKPN and ST45 NDM-1-producing CRECL. Furthermore, plasmid typing demonstrated that IncF and IncFIB were the most prevalent plasmids in KPC-2 producers, while IncX3/IncX2 and ColE were widely spread in NDM producer and OXA-232 producer, respectively. Then, class 1 integron intergrase intI1 was positive in 74.0% (71/96) of the \"CRE colonization\" group and 52.9% (37/70) of the \"CRE infection\" group.
This study revealed that CRE strains from intestinal colonization and nosocomial infection showed a partial correlation in the prevalence of CRE, especially for ST11 KPC-2-producing CRKPN and ST45 NDM-1-producing CRECL. Therefore, before admission, long-term active screening of rectal colonization of CRE isolates should be emphasized.