新的质粒介导的碳青霉烯酶IMI-3传播机制研究  

Study on the transmission mechanism of the novel plasmid-mediated carbapenemase IMI-3

作　　者：俞红娣[1] 俞云松[2] 杜小幸[2] 陈亚岗[2] 李兰娟[2] 

机构地区：[1]浙江大学医学院附属第一医院呼吸科,杭州310003 [2]浙江大学医学院附属第一医院传染科,杭州310003

出　　处：《中国抗感染化疗杂志》2005年第5期282-284,共3页Chinese Journal of Infection and Chemotherapy

基　　金：国家自然科学基金资助项目(编号:30270074)

摘　　要：目的明确新的质粒介导的碳青霉烯酶IMI-3传播机制。方法采用E试验测定抗菌药物MIC,接合试验、酶切克隆筛选及鸟枪法测序对编码基因IMI-3传播机制进行研究。结果发现阳性克隆菌E.colipT103有5个开放读码框(ORF)。在编码基因IMI-3的两侧各有一相同的插入序列,氨基酸序列与IS903有71%的同源性。鸟枪法测序显示IMI-3与染色体介导的IMI-1有99%的同源性。结论IMI-3编码基因是由位于染色体上的IMI-1经点突变通过转座酶Tn903转移至可接合性质粒上。Objective To investigate the transmission mechanism of the novel plasmid-mediated carbapenemase IMI-3. Methods The minimum inhibitory concentrations （MICs） were determined by E test. The transmission mechanism of the novel plasmidmediated carbapenemase IMI-3 was studied by conjugation experiment, restriction endonuclease digestion, cloning and screening, shot gun sequencing. Results The inserted fragment from E. coli pT103 contained five open reading frames （ORFs）. In each flanking side of the encoding gene IMI-3, there is an identical inserted sequence, which had 71% homology with IS903. Sequence analysis showed that IMI-3 has 99% homology with chromosome-mediated IMI-1 in terms of the deduced amino acid sequence. Conclusions This study confirms that IMI-3 is transferred from ehromosome-mediated IMI-1 with point mutations to plasmid via Tn903.

关 键 词：质粒介导 碳青霉烯酶 传播机制 

分 类 号：R446.5[医药卫生—诊断学]