产NDM-5大肠埃希菌的鉴定及特征分析

Identification and Characterization of NDM-5-Producing E.coli

对分离自血液标本的1株碳青霉烯类耐药大肠埃希菌(Escherichia coli)SCNJ06进行特征分析,以期为临床耐药菌株感染的防治提供理论参考。采用全基因组测序以及生物信息学分析,该菌株属于序列型167(ST167),含有11种耐药基因,分别是rmtB、aph(3″)-Ib、aph(6)-Id、blaNDM-5、blaTEM-1B、blaCTX-M-55、fosA3、floR、sul2、tet(A)和mdf(A)。其中,blaNDM-5位于IncX3型质粒pNDM5SCNJ06上,mdf(A)位于染色体上,其余耐药基因位于IncFII型质粒prmtBSCNJ06上。接合试验显示,pNDM5SCNJ06和prmtBSCNJ06均能够发生接合转移。应加强抗菌药物临床应用管理和医院感染防控措施,重视细菌耐药监测工作。

The characteristic of carbapenem-resistant E.coli SCNJ06 isolated from a blood sample was analyzed so as to provide theoretical reference to prevent infection and treatment of clinically drug-resistant strains.Full genome sequencing and bioinformatics were adopted for the analysis.The results showed that the strain belonged to the sequence type 167,and contained 11 drug-resistance genes,they are rmtB,aph(3″)-Ib,aph(6)-Id,blaNDM-5,blaTEM-1 B,blaCTX-M-55,fosA3,floR,sul2,tet(A),and mdf(A)respectively.Among them,blaNDM-5 was located on the IncX3 type plasmid pNDM5SCNJ06,mdf(A)located on the chromosome,and the rest on the IncFII type plasmid prmtBSCNJ06.Conjugation experiments showed that pNDM5SCNJ06 and prmtBSCNJ06 both were self-transmissible.Therefore,it is necessary to strengthen hospital infection control and stewardship of clinical management and the hospital anti-infection measurements,and pay more attention to surveillance of bacterial drug-resistance.