耐碳青霉烯类肠杆菌目细菌分子流行病学特征及耐药性

目的 探讨耐碳青霉烯类肠杆菌目细菌(CRE)的分子流行病学特征，研究CRE耐药特点及同源性。方法 收集宁夏某医院2018年1月—2021年5月临床分离的158株非重复CRE,采用聚合酶链式反应(PCR)检测耐药基因，应用改良碳青霉烯灭活试验(mCIM)联合EDTA改良碳青霉烯灭活试验(eCIM)进行表型确证，采用质粒接合试验分析bla_NDM水平转移情况，运用多位点序列分型(MLST)进行同源性分析。结果 158株CRE主要为肺炎克雷伯菌(61株，38.61%),其次是阴沟肠杆菌(37株，23.42%)和大肠埃希菌(23株，14.56%),检出CRE最多的科室为ICU和烧伤整形科，CRE标本来源排名前四的分别是痰、脓性分泌物、引流液和无菌中段尿，检出耐药基因以新德里金属-β-内酰胺酶(NDM)为主。23株大肠埃希菌mCIM联合eCIM试验阳性率达95.65%,质粒接合试验成功将20株大肠埃希菌中15株菌株的bla_NDM基因转移到大肠埃希菌J53AZ^R,接合子菌株对亚胺培南、美罗培南和头孢菌素类抗生素的耐药性较受体菌增强。M...

Molecular epidemiological characteristics and drug resistance of carbape-nem-resistant Enterobacterales

Objective To investigate the molecular epidemiological characteristics of carbapenem-resistant Entero-bacterales (CRE), study drug resistance characteristics and homology of CRE.Methods 158 strains of non-repetitive CRE isolated from a hospital in Ningxia from January 2018 to May 2021 were collected, drug resistance genes were detected by polymerase chain reaction (PCR), phenotypic confirmation was conducted by modified carbapenem inactivation method (mCIM) combined with EDTA-modified carbapenem inactivation method (eCIM), horizontal transfer of bla_NDM was analyzed by plasmid conjugation test, homology analysis was performed by multilocus sequence typing (MLST).Results 158 CRE strains were mainly Klebsiella pneumoniae (61 strains, 38.61%), followed by Enterobacter cloacae (37 strains, 23.42%) and Escherichia coli (23 strains, 14.56%), the departments with most detected CRE were intensive care unit as well as burn and plastic surgery department. The top four specimen sources of CRE strains were sputum, purulent secretions, drainage fluid and sterile midstream urine respectively, the detected drug-resistant gene was mainly New Delhi metallo-β-lactamase (NDM). Positive rate of 23 strains of Escherichia coli mCIM combined with eCIM test was 95.65%, plasmid conjugation test successfully transferred bla_NDM gene of 15 strains from 20 Escherichia coli to Escherichia coli J53AZ^R, resistance of the conjugated strains to imipenem, meropenem and cephalosporins was stronger than that of the recipient strains. Fourteen ST types were detected from 23 strains of Escherichia coli by multi-locus sequence typing (MLST), mainly ST10 and ST410.Conclusion CRE strains in the hospital mostly come from ICU, mainly carrying bla_NDM resistance gene, and have high resistance to commonly used antimicrobial agents in clinic, hospital should strengthen the supervision of antibiotics use and guide the rational drug use in clinical practice. NDM enzyme subtypes in this region gradually change, thus continuous monitoring should be carried out to find new subtypes in time.