应用PCR-SSCP检测结核分支杆菌链霉素耐药基因的研究

DETECTION OF STREPTOMYCIN RESISTANT GENE IN M. TUBERCULOSIS CLINICAL ISOLATES

结核病耐药问题十分严重，传统的药敏实验需1～2月。Sm是一线抗结核药物，结核分支杆菌耐Sm最常见的分子机制是由于核糖体S12蛋白编码基因（rpsL）突变。该文应用PCR－SSCP分析了62个结核分支杆菌临床分离株的rpsL基因，以H37Rv标准菌株为对照，13个药物敏感菌株中12个rpsL基因未见SSCP异常；37个耐Sm株中，31个（83．8％）有rpsL基因泳动异常；12个耐其它抗结核药物林中，仅1个单链DNA泳动异常。因此，PCR－SSCP有希望成为简便、快速地检测结核分支杆菌耐药突变株的方法，弥补常规药敏试验的不足，指导临床治疗。

Streptomycin is one of the main anti-tuberculosis agents. The primary molecular mechanism of streptomycin resistance in M. tuberculosis has been shown to result from missense mutations in the rpsL gene, which encedes the ribosomal protein S12. PCR-SSCP technique was used to detect the rpsL, gene in 62 M. tubcrculosis c1inical isolates and the strain H37Rv was used as the control. There were no apparent differences between the SSCP profiles of the rpsL, PCR fragments from 12 of the 13 drug Susceptible isolates and those of the H37Rv strain. The SSCP profiles of 31 of the 37 streptomycin resistant isolates were obviously different from the drug susceptible isolates and the control group. One of the 12 isolates found to be resistant to other drugs also showed apparent SSCP differences from the drug susceptible isolates. These results indicate that PCR-SSCP may become a simple, rapid and reliable diagnostic test for rcsistance, and could eventually improve patients management and care.