目的 了解产气肠杆菌携带blaNDM-1质粒的转移性、复制子分型及周围环境.方法 产气肠杆菌HN-NDM0711为实验菌株,利用接合实验研究其质粒的转移性,对接合子进行稳定性试验,采用质粒复制子分型法对质粒进行分型,利用染色体步移技术对基因blaNDM-1上下游进行测序,使用BLASTN和BLASTP对基因组序列进行比对,使用Vector NTI 11.5.1注释并生成序列管道图,序列通过软件Banklt递交至Genbank.结果 产气肠杆菌HN-NDM0711接合实验阳性,阳性接合子稳定传代4d后,所有克隆株对亚胺培南和美罗培南的最低抑菌浓度(MIC)均未发生变化,基因blaNDM-1均为阳性.质粒复制子为IncA/C型;基因blaNDM-1位于不常见的插入序列ISA-ba14和IS91之间,在blaNDM-1的上游出现一个Tn3转座子和I型整合子,整合子上含有一个由庞大镶嵌序列构成的少见耐药基因盒.结论 IncA/C型质粒pHN-NDM0711携带基因blaNDM-1及耐药基因盒,可能源于不同抗菌药物选择压力下的基因重组,建议严格控制临床、工业和农业抗菌药物的使用,从源头上减少此类细菌的产生.%Objective To study plasmid-mediated transfer,plasmid replicon typing,and genetic environment of blaNDM-1 gene in Enterobacteraerogenes(E.aerogenes).Methods E.aerogenes HN-NDM0711 was used as the subject of this research,the transferable properties of plasmid were analyzed by conjugation testing,conjugant was performed stability testing,plasmid type was determined by PCR-based replicon typing (PBRT),downstream and upstream of blaNDM-1 were sequenced using chromosome walking method,genetic context was analyzed by BLASTN and BALSTP,as well as annotated using Vector NTI 11.5.1 software,sequence pipeline graph was made,the sequence was submitted to Genbank through software Banklt.Results The conjugation testing of E.aerogenes pHN-NDM0711 was positive,after positive conjugant was conducted 4-day passage,minimal inhibitory concentrations (MICs) of imipenem and meropenem to all the cloned strains didn't change,blaNDM-1 were all positive.The replicon type was IncA/C;blaNDM-1 gene was localized between ISAba14 and IS91,at upstream of the blaNDM-1,class 1 integron and Tn3 transposon were identified,class 1 integron contained a new mosaic structure of a drug-resistant resistance gene cassette.Conclusion E.aerogenes pHN-NDM071 1,bearing blaNDM-1 gene in IncA/C plasmid,derived from gene recombination under different antimicrobial selection pressure.Antimicrobial use in clinical,industrial and agricultural area should be strictly controlled,so as to reduce the emergence of such bacteria.
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