中文摘要：

目的运用实时定量PCR（qRT-PCR）检测66株结核分枝杆菌蛋白编码基因（fbpB,psts1,mpt64）的表达水平,探讨结核分枝杆菌耐药菌株与敏感菌株,北京基因型菌株与非北京基因型菌株的蛋白抗原在转录水平的差异。方法根据GenBank提供的序列,设计特异性引物,扩增目的基因片段,克隆入载体,重组质粒经纯化及梯度稀释,应用qRT-PCR检测基因的表达水平。结果北京基因型菌株psts1基因表达水平与非北京基因型菌株比较差异有统计学意义（t=3.721,P〈0.01）;耐药菌株mpt64基因表达水平与敏感菌株比较差异有统计学意义（t=3.951,P〈0.01）。结核分枝杆菌活菌的扩增曲线呈典型的S型,结核分枝杆菌死菌和非结核分枝杆菌呈水平直线,未检测到荧光信号。结论北京基因型结核分枝杆菌psts1基因的表达量低于非北京基因型,结核分枝杆菌耐药菌株mpt64基因的表达量低于敏感株。

英文摘要：

Objectives To use quantitative real-time PCR to detect the level of expression of the genes fbpB,psts1,and mpt64 coding for proteins in 66 strains of Mycobacterium tuberculosis and to explore variability in protein antigens of the Beijing genotype and non-Beijing genotype at the transcriptional level in drug-resistant strains and sensitive strains.Methods Specific primers were designed in accordance with the GenBank database.The amplified PCR fragments were cloned into respective vectors,and recombinant plasmids were purified and serially diluted.Levels of gene expression were detected using qRT-PCR.Results There was a statistically significant difference（t=3.721,P〈0.01）in the expression of psts1 in the Beijing genotype compared to the non-Beijing genotype.There was a statistically significant difference（t=3.951,P〈0.01）in the expression of mpt64 in drug-resistant strains compared to sensitive strains.The amplification curve for live M.tuberculosis was a characteristic S curve.The curve for dead M.tuberculosis and nontuberculous mycobacteria was a flat line;a fluorescent signal was not detected.Conclusion This study found that the expression of psts1 in the Beijing genotype is down-regulated compared to the non-Beijing genotype and the expression of mpt64 in drug-resistant strains is down-regulated compared to sensitive strains.