摘要
目的分析淋球菌MtrR基因调控区删除突变与淋球菌耐药之间的关系。方法以临床收集的淋菌株为出发株,用制备的突变MtrR DNA片段进行转染试验,筛选并纯化MtrR基因调控区9bp片段删除的突变株,测定出发株和转染株对多种抗菌素的最小抑菌浓度(MIC)值和MtrCDE基因转录量。结果在18株临床株中,有15株被转染为目的突变株,其余3株始终不能被转染。转染株与出发株相比,对Triton-100的MIC值平均提升28.64倍,对脂溶性抗生素红霉素和四环素的MIC值平均升高8.55倍和5.53倍,差异均有统计学意义(均P<0.01);对氯霉素和链霉素的平均MIC值,两者差异无统计学意义(均P>0.05)。RT-PCR产物的凝胶电泳分析显示,所有转染株MtrCDE基因转录水平均有不同程度的升高,且与淋球菌对脂溶性抗菌试剂的耐药水平呈正相关。结论转染株MtrR基因调控区9bp片段的删除可通过阻断MtrR基因表达而提高MtrCDE基因的转录水平,从而诱导淋球菌耐药。
Objective To determine the relationship between the mutation of regulation region of MtrR gene and the multiple resistance of Neisseria gonorrhoeae.Methods The clinical strains were transformed from mutation DNA fragments prepared before.The transformants whose regulation region of MtrR gene contained a deletion of 9 bp segment were selected and purified.The MIC and the quantity of MtrCDE transcription about all of these experimental strains were tested.The data were analyzed statistically.Results Fifteen strains of transformants had been obtained successfully by the introduction of the mutated fragments to strains of clinical Neisseria gonorrhoeae.But other three clinical strains out of 18 strains collected could not been transformed despite repeated efforts.The results for transformants and their derivative strains revealed that the MIC of transformants to Triton-100,erythromycin and tetracycline was 28.64 times,8.55 times and 5.53 times more than that of clinical strains on average,respectively.However,there was no apparent increment of MIC to hydrophilic antimicrobial agents.The electrophoretic analysis of RT-PCR products revealed that the level of MtrCDE transcription was enhanced in all transformants,and there was a positive correlation between the level of MtrCDE transcription and resistance of Neisseria gonorrhoeae to hydrophobic antimicrobial agents.Conclusion It was seemly that the 9 bp deletion in the MtrR gene regulation region would impact transcription of MtrR,and as a result,the expression of MtrR which is the transcription depressor of MtrCDE is blocked.
出处
《华中科技大学学报（医学版）》
CAS
CSCD
北大核心
2012年第3期348-352,共5页
Acta Medicinae Universitatis Scientiae et Technologiae Huazhong
基金
国家自然科学基金资助项目(No.30371293)
关键词
奈瑟氏淋球菌
基因突变
Mtr耐药
Neisseria gonorrhoeae
gene mutation
Mtr drug resistance
