中文摘要：

目的设计针对结核杆菌耐乙胺丁醇embB303codon的分子信标，尝试运用荧光分光光度计直接观测液相中分子信标与embB303codon扩增产物杂交后的荧光信号，从而检出该位点突变。方法运用软件Beacondesigner设计embB基因包含303codon的分子信标，应用荧光分光光度计检测embB303codon扩增片段与探针杂交后荧光信号，同时对扩增产物测序并作比较。结果通过荧光分光光度计观测到结核标准株及耐乙胺丁醇embB303codonPCR产物与分子信标杂交后荧光信号存在显著差异；33株耐乙胺丁醇组与10株H37RV标准株对照组荧光信号强度比较，耐乙胺丁醇组embB303codon突变检出率为6％，测序法突变检出率为6％。结论embB303codon点突变不是结核杆菌耐乙胺丁醇的主要原因；应用荧光分光光度计直接检测液相杂交荧光具有简单、灵敏等优点；分子信标技术可以有效检测单碱基靶点突变。

英文摘要：

Objective To design molecular beacon of detecting embB303 codon of ethambutol resistant MTB and detect mutation site of embB 303 codon. Methods The software, Beacon designer, was used to design the molecular beacon of embB303 codon. The fluorescence signal from hybridization between the amplified product and probe was analyzed with fluorescence spectrophotometer and sequencing. Results There was obvious difference of PCR products from standard strain and Ethambutol resistant one with fluoresce. The rate of resistant Ethambutol was 6% with both fluoresce and sequencing. Conclusion The mutation site of embB 303 codon is not the main reason of Ethambutol resistant MTB. Fluorescence spectrophotometer demonstrates advantages in sensitiveness and simplicity in liquid.