淋病奈瑟菌mtrR基因启动子区的IR区碱基缺失与其耐药性关系的研究

目的探索淋病奈瑟菌(NG,简称淋球菌)多传递耐药系统R基因(m trR)启动子区反向重复序列(IR)区基因缺失与淋病奈瑟菌染色体所介导的耐药性的关系。方法以琼脂稀释法做药物敏感试验,选择临床敏感株采用自身配对法以次抑菌浓度法诱导筛选出对不同抗生素耐药的淋球菌株,以聚合酶链反应(PCR)扩增包含IR区在内的目的基因后,对扩增产物测序,并将其IR区基因突变与临床分离自然耐药株比较。结果8株敏感株及24株单独耐1种药物菌株及1株诱导的多重耐药株无IR区基因突变,7株诱导多重耐药菌株IR区有碱基A/T缺失,与自然多重耐药株两者相比较碱基缺失无差异。结论淋球菌染色体IR区基因缺失与单独耐一种药物菌株产生无关,IR区基因缺失参与了淋球菌多重耐药株的产生,人工诱导的多重耐药株与自然多重耐药株IR区碱基突变无差异。

Study of Relationship Between IR Gene Deletion in The mtrR Gene Promoter and Antibiotic Resistance of Neisseria Gonorrhoeae

Objective To study relationship between IR's gene deletion in the promoter of mtrR gene and antibiotic resistance of Neisseria Gonorrhoeae(NG).Methods The drug sensitivities of strains were tested by agarose-dilution-method.The different antibiotic resistant strains were induced with subordinate minimal inhibitory concentration(sMIC) from clinic isolated sensitive strains.The multiple transferable resistant system's(mtr) inverted repeat sequence(IR) of Neisseria gonorrhoeae was sequenced after amplification by polymerase chain reaction(PCR).Results Eight sensitive or twenty-four single antibiotic resistant or one multiple antibiotic resistant strains had no base deletion in IR gene but seven induced multiple antibiotic resistant strains had a single base deletion(T/A),and there was no difference between IR gene mutation of induced multiple antibiotic resistant strains and those of clinic ones.Conclusion There is no relationship between mutation of IR gene and single antibiotic resistance of NG,and there is not difference between mutation of IR gene of clinic strains and that of induced one,but single-base deletion of IR gene might result in multiple antibiotic resistance.