耐碳青霉烯类阴沟肠杆菌耐药基因分析

目的探讨耐碳青霉烯类阴沟肠杆菌相关耐药基因分布情况。方法收集2015年1月至2017年12月佛山市第一人民医院分离的16株阴沟肠杆菌为研究对象,利用VITEK2-Compact全自动微生物分析系统进行细菌鉴定及药敏试验。采用改良Hodge试验和乙二胺四乙酸(EDTA)协同试验进行耐药表型筛选。采用PCR法检测碳青霉烯酶基因(bla IMP、bla KPC、bla NDM、bla VIM、bla OXA-48)、ISCR1、Ⅰ类整合酶、Ⅰ类整合子基因盒基因。结果16株阴沟肠杆菌对亚胺培南、美罗培南均耐药。16株细菌改良Hodge试验和EDTA协同试验均阳性。16株均携带有碳青霉烯酶基因,其中14株携带bla NDM-1,2株携带bla IMP-4。16株ISCR1、Ⅰ类整合酶和Ⅰ类整合子基因盒均阳性,携带的基因盒主要由dfrA17-aadA5或dfrA15-aadA2组成。结论该院耐碳青霉烯类阴沟肠杆菌携带的碳青霉烯酶基因以bla NDM-1为主。

Study on resistance gene in carbapenemase-resistant Enterobacter cloacae

Objective To investigate the distribution of resistance gene in carbapenemase-resistant Enterobacter cloacae isolates.Methods A total of 16 Enterobacter cloacae isolates were collected between January 2015 and December 2017 in the First People′s Hospital of Foshan.The identification and antimicrobial susceptibility were analyzed by VITEK2-Compact microorganism analysis system.The modified Hodge test and EDTA double-disk synergy test were used for detection of carbapenemase-resistant phenotype.The genes of the carbapenems,bla IMP,bla KPC,bla NDM,bla VIM and bla OXA-48 were analyzed by PCR.Results A total of 16 isolates were all resistant to imipenem and meropenem.All isolates were positive in the modified Hodge test and EDTA double-disk synergy test.Fourteen strains carried bla NDM-1 and two strain carried bla IMP-4.ISCR1,classⅠintegrase and gene cassettes were detected in all strains.Gene cassette was mainly made up of dfrA17-aadA5 or dfrA15-aadA2.Conclusion The bla NDM-1 is the dominant genotype in the carbapenemase-resistant Enterobacter cloacae in our hospital.