原发性耐药是耐药结核病产生的重要原因

Primary drug-resistance is the main cause of drug-resistant tuberculosis

目的研究原发性耐药在产生耐药结核病中的作用。方法对上海市疾病预防控制中心收集保存的1996年至2004年结核分枝杆菌临床菌株进行分析统计,计算原发性耐药和获得性耐药的比例;并对16例复发耐药患者前后发病菌株进行结核分枝杆菌散在分布重复单位(mycobacterialinterspersedrepetitiveunits,MIRU)基因型比较分析。结果在保存的初治患者的8120株结核分枝杆菌中,耐药菌株707株,耐药率为8.7%;复治患者的菌株610株,耐药菌株150株,耐药率为24.6%。初治和复治患者中耐药率均有上升趋势。以初治患者耐药代表原发性耐药,复治患者耐药代表获得性耐药,其原发性耐药占总耐药菌株的82.5%。在16例复发耐药患者中,13例患者在两次发病时分离的菌株基因型不一致,可能是由于重新感染了耐药菌株所致,属于原发性耐药。结论原发性耐药是目前耐药结核病产生的重要原因,该结果提示有效控制结核病的传染源是减少耐药结核病产生的关键。

Objective To investigate the main cause of drug-resistant tuberculosis. Methods Clinic isolates of Mycobacterium tuberculosis from 1996 to 2004 in Shanghai were analyzed and the proportion of isolates from new cases （the proxy of primary drug-resistance ） and retreatment cases （the proxy of acquired drug-resistunce） were calculated. Mycobacterial interspersed repetitive units （MIRU）genotyping was performed and analyzed on pairs of isolates of Mycobacterium tuberculosis from 16 recurrent patients with drug-resistant tuberculosis. Results Of all 8 120 isolates of Mycobacterium tuberculosis from new cases, 707 isolates （8. 7% ） were drug resistant. Of all 610 isolates from retreatment cases, 150 isolates （24. 6% ） were drug resistant. Primary drug resistance accounted for 82. 5% （707/857） of all drug resistant isolates. Based on the MIRU genotypes, 13 of all 16 recurrent drug-resistant patients were reinfected with new drugresistant strain of Mycobacterium tuberculosis. Conclusion Primary drug-resistance is the main cause of drug-resistant tuberculosis.