摘要
目的 研究结核分枝杆菌耐喹诺酮类药物的分子机制 ,探索四川地区耐喹诺酮结核分枝杆菌临床分离株的耐药基因突变特征。方法 采用绝对浓度法检测结核分枝杆菌临床分离株的最小抑菌浓度 (MIC) ,再通过聚合酶链反应 -单链构象多态性 (PCR- SSCP)和直接测序检测结核分枝杆菌耐喹诺酮类药物临床分离株 gyr A耐药决定区 (QRDR)突变 ,并和标准株 H 37Rv比较。结果 6 8株临床分离株中 ,14株喹诺酮药物敏感株和 8株低耐药株未发现 gyr A耐药决定区基因突变 ,2 5株高耐药株、11株低耐药株和 10株药物敏感株检测到 gyr A基因突变 ,高耐药株突变率为 10 0 % ,低耐药株突变率为 5 8% ,敏感株突变率为 4 2 % ,总的突变率为 6 8%。根据 SSCP条带 ,gyr A突变可分成 4种类型 ,测序发现分别为 Ser95 Thr、Asp94 Gly、Ala90 Val、Ala83Val突变。结论 结核分枝杆菌耐喹诺酮与 gyr A基因突变密切相关 ,gyr A基因突变是耐喹诺酮结核分枝杆菌耐药性的主要分子机制。
Objective To investigate the molecular mechanism of quinolone-resistance of M. tuberculosis and characterize the gene mutation in Sichuan Province.Methods Susceptibility of the clinical isolates to quinolones (ofloxacin, ciprofloxacin and sparfloxacin) was tested by the absolute concentration method. GyrA gene quinolone resistance-determining region (QRDR) mutations of M. tuberculosis were detected with PCR-SSCP and DNA sequencing. Results Of 68 clinical isolates of M. tuberculosis, 25 high-resistant, 11 low-resistant and 10 sensitive isolates were noted to have abnormal gyrA SSCP profile and different gyrA sequences from the standard strain H37Rv, and 14 sensitive and 8 low-resistant isolates were found with no mutation of gyrA gene. DNA sequencing unveiled Ser→Thr mutation at codon 95, Asp→Gly at codon 94, Ala→Val at codon 90, and Ala→Val at codon 83. Conclusion This study confirmed the strong correlation between the quinolone-resistance and the mutation of gyrA gene, which might be a major molecular mechanism of quinolone-resistance in M. tuberculosis. The types of mutations exhibit no difference between Sichuan Province and other areas in China.
出处
《四川大学学报(医学版)》
CAS
CSCD
北大核心
2004年第3期313-315,共3页
Journal of Sichuan University(Medical Sciences)
基金
国家自然科学基金 (批准号 3 0 2 71172 )资助
关键词
结核分枝杆菌
喹诺酮药物耐受性
聚合酶链反应-单链构象多态性
Mycobacterium tuberculosis Quinolone Drug resistance Polymerase chain reaction-single strand conformation polymorphism