Department of Microbiology and Immunology, Mahidol University, Bangkok 10400, Thailand.
Microbiol Immunol. 2013 Jan;57(1):21-9. doi: 10.1111/1348-0421.12000.
The emergence of drug resistant Mycobacterium tuberculosis has become a global threat to tuberculosis (TB) prevention and control efforts. This study aimed to determine the drug resistance profiles and DNA fingerprints of M. tuberculosis strains isolated from patients with relapsed or retreatment pulmonary TB in Chiang Rai province in northern Thailand. Significant differences in multidrug resistance (MDR) (P = 0.025) and resistance to isoniazid (P = 0.025) and rifampin (P = 0.046) between first and second registrations of patients with retreatment TB were found. However, there were no significant differences in resistance to any drugs in patients with relapsed TB. The rate of MDR-TB strains was 12.2% among new patients at first registration, 22.5% among patients with recurrence who had previously undergone treatment at second registration and 12.5% at third registration. Two retreatment patients whose initial treatment had failed had developed MDR-TB with resistance to all TB drugs tested, including rifampin, isoniazid, streptomycin and ethambutol. IS6110-RFLP analysis revealed that 66.7% (10/15 isolates) of MDR-TB belonged to the Beijing family. In most cases, IS6110-RFLP patterns of isolates from the same patients were identical in relapse and retreatment groups. However, some pairs of isolates from retreatment patients after treatment failure had non-identical IS6110-RFLP patterns. These results suggest that, after failure and default treatment, patients with retreatment tuberculosis have a significantly greater risk of MDR-TB, isoniazid and rifampin resistance than do other patients.
耐药结核分枝杆菌的出现已成为全球结核病（TB）防控工作的威胁。本研究旨在确定来自泰国北部清莱省复发性或复治性肺结核患者的结核分枝杆菌分离株的耐药谱和 DNA 指纹。在复治性肺结核患者的首次和第二次登记中，耐多药（MDR）（P = 0.025）和异烟肼（P = 0.025）和利福平（P = 0.046）的耐药性存在显著差异。然而，在复发性肺结核患者中，对任何药物的耐药性均无显著差异。首次登记的新患者中 MDR-TB 菌株的发生率为 12.2%，第二次登记的复发患者中曾接受过治疗的患者为 22.5%，第三次登记的患者为 12.5%。两名初始治疗失败的复治患者已发展为 MDR-TB，对所有测试的抗结核药物均耐药，包括利福平、异烟肼、链霉素和乙胺丁醇。IS6110-RFLP 分析显示，66.7%（10/15 株）的 MDR-TB 属于北京家族。在大多数情况下，同一患者的分离株的 IS6110-RFLP 模式在复发和复治组中是相同的。然而，一些治疗失败后复治患者的分离株的 IS6110-RFLP 模式不相同。这些结果表明，在治疗失败和失访后，复治性肺结核患者发生 MDR-TB、异烟肼和利福平耐药的风险显著高于其他患者。
