临床分离耐碳青霉烯类阴沟肠杆菌的耐药机制和同源性分析

Drug resistance mechanisms and homology of clinical carbapenem-resistant Enterobacter cloacae isolates

目的 分析临床分离耐碳青霉烯类阴沟肠杆菌的耐药机制和同源性,为治疗及医院感染控制提供数据支持。方法 对2019年成都市龙泉驿区第一人民医院临床分离的所有阴沟肠杆菌进行药物敏感试验。同时采用碳青霉烯酶抑制剂增强试验对耐碳青霉烯类阴沟肠杆菌进行耐药表型检测,采用PCR技术进行耐药基因检测,采用肠杆菌目基因间重复序列引物PCR技术进行同源性分析。结果 2019年临床标本共检出43株阴沟肠杆菌,其中耐碳青霉烯类阴沟肠杆菌(CRECL)11株,主要来源于重症医学科,主要分离自痰液标本。耐碳青霉烯类阴沟肠杆菌对头孢类抗菌药物的耐药率高于80%,对喹诺酮类的耐药率则低于30%。耐碳青霉烯类阴沟肠杆菌的耐药表型主要为同时产A类碳青霉烯酶和B类碳青霉烯酶,耐药基因主要为bla_(KPC)和bla_(NDM),未检出D类耐药基因。11株耐碳青霉烯类阴沟肠杆菌可分为5型,其中最多的基因型有6株,这6株菌主要分离自重症医学科和重症医学科转科密切的相关科室。结论 耐碳青霉烯类阴沟肠杆菌对多数抗菌药物的耐药率高,耐药基因以bla_(KPC)和bla_(NDM)为主,11株耐碳青霉烯类阴沟肠杆菌可分为5型,而且多株同一型别在医院出现,应加强监测,严格落实各项消毒隔离措施,严防耐碳青霉烯类阴沟肠杆菌引发院内感染和播散流行。

OBJECTIVE To observe the drug resistance mechanisms and homology of clinical Enterobacter cloacae isolates so as to provide data support for control and treatment of nosocomial infection. METHODS The drug susceptibility testing was performed for all of the clinical E.cloacae isolates that were isolated from the First People′s Hospital of Longquanyi District of Chengdu in 2019. The drug resistance phenotypes of the carbapenem-resistant E.cloacae strains were detected by carbapenemase inhibitor enhancement test, drug resistance genes were detected by using PCR, and the homology of the strains was observed by using enterobacterial repetitive intergenic consensus polymerase chain reaction(ERIC-PCR). RESULTS 43 strains of E.cloacae were isolated from clinical specimens in 2019, 11 of which were carbapenem-resistant E.cloacae, most of the strains were isolated from intensive care unit and sputum specimens. The drug resistance rate of the carbapenem-resistant E.cloacae to cephalosporins was more than 80%, while the drug resistance rate to quinolones was less than 30%. Class A carbapenemase and class B carbapenemase were the major drug resistance phenotypes of the carbapenem-resistant E.cloacae, blaand blawere the major drug resistance genes, and class D drug resistance genes were not detected. The 11 strains of carbapenem-resistant E.cloacae could be divided into 5 genotypes, and there were 6 strains that belonged to the predominant genotype, and most of the 6 strains were isolated from intensive care unit or the departments that were closely related to the transferring to ICU. CONCLUSION The carbapenem-resistant E.cloacae strains are highly resistant to most of antibiotics, blaand blaare the major drug resistance genes. The 11 strains of carbapenem-resistant E.cloacae can be divided into 5 genotypes, and some strains of the same genotype are prevalent in the hospital. It is necessary to strengthen monitoring and rigidly carry out the disinfection and isolation measures so as to prevent nosocomial infection caused by the carbapenem-resistant E.cloacae and the spread as well as prevalence.