目的 研究鸟胞内分枝杆菌复合群(MAC)MAV3104基因编码蛋白与药物外排的关系。方法 以MAC标准株基因组为模板,扩增MAV3104基因,构建pMV261-MAV3104c重组质粒;测序正确后,转化重组质粒到大肠杆菌DH5并在MAC标准株中诱导表达, Western Blot鉴定MAV3104表达;按照CLSIM24-A2的操作要求检测MAC标准株对克拉霉素的敏感性及外排泵抑制试验。结果 经基因测序及Western Blot蛋白表达验证重组质粒构建成功;MAV3104过表达能提高鸟分枝杆菌对克拉霉素的MIC,且硫利达嗪能抑制该作用;MAV3104过表达也能提高胞内分枝杆菌对克拉霉素的MIC,但硫利达嗪对其没有抑制效应。结论 MAV3104转运蛋白介导的药物外排在鸟分枝杆菌耐克拉霉素中起重要作用。

Objective To investigate the association of the protein coded by Mycobacterium avium-Mycobacterium intracellulare complex in MAV3104 in drug efflux of Clarithromycin. Methods According to the Mycobacterium avium-Mycobacterium intracellulare complex standard strain, the MAV3104 gene was amplified by PCR and cloned into expression vector pMV261 to generate the recombinant plasmids. After verification by sequence analysis, the recombinant plasmids was transformed into E. coli DH5 andMycoba ctenum avium-Mycobacterium intracellulare complex standard strain. To identify the protein expression by western blotting and investigate the sensitivity of clarithromycin and efflux pump inhibition test in the light of CLSIM24-A2 protocol. Results It was verified by sequence analysis and western blotting that the recombinant plasmids were successfully constructed. Over expression of Mycobacterium avium MAV3104 gene could enhance clarithromycin MIC, which could be inhibited by thioridazine. Over expression of Mycobacterium intracellulare MAV3104 gene also could enhance clarithromycin MIC, but it could not inhibited by thioridazine. Conclusion This study demonstrates that efflux pumps mediated by MAV3104 protein play an important role in Mycobacterium avium resistance to clarithromycin.