异烟肼耐药耻垢分枝杆菌的建立及药物敏感性的测定
Establishment and drug susceptibility test of isoniazid resistant Mycobacterium smegmatis
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摘要:
耐药结核病的涌现, 使发展新型抗耐药结核药物变得尤为迫切。本研究选择生长快且无致病性的耻垢分枝杆菌为研究对象, 探索快速评价药物抗异烟肼耐药结核分枝杆菌的能力。inhA是异烟肼的作用靶点, 由于inhA的突变或者过表达可以引起结核分枝杆菌对异烟肼耐药性的产生。通过将inhA克隆入pMV261中, 构建过表达inhA的耻垢分枝杆菌。结果显示, 过量表达inhA的耻垢分枝杆菌对异烟肼的敏感性下降了100倍以上。建立了利用刃天青为指示剂的抗异烟肼耐药株的快速药效评价方法, 可快速对药物的活性进行定性或定量评价, 为进行新型抗结核药物的高通量筛选和药效评价奠定基础。
Abstract:With the emergence of drug resistant tuberculosis, it is very urgent to find novel anti-tuberculosis drugs, especially novel anti-drug-resistant tuberculosis drugs. Because of the slow growth and the need to work in a biosafty environment of Mycobacterium tuberculosis, the development of evaluation of drug effect is severely impeded. In order to solve these issues, non-pathogenic fast-growing Mycobacterium smegmatis is introduced as test organism. The inhA is one of a target of isoniazid (INH) overexpression or mutation of this gene in Mycobacterium tuberculosis conferring resistant to INH. A recombinant plasmid bearing inhA was constructed and electroporated into Mycobacterium smegmatis, using shuttle expression vector pMV261. Transformants were induced to express a protein of inhA, identified by SDS-PAGE. Results show that Mycobacterium smegmatis containing inhA plasmids exhibited 100-fold or greater increased resistance to INH, but it conferred no increased resistance to others first-line anti-tuberculosis drugs. Resazurin microtiter assay plate testing of Mycobacterium smegmatis susceptibility to drugs is a rapid, simple, and inexpensive method and could decrease color background of drugs by detecting fluorescence. It will be benefit for high- throughout screening of drugs of anti-isoniazid-resistant Mycobacteria.
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