Rapid and inexpensive drug susceptibility testing of Mycobacterium tuberculosis with a nitrate reductase assay
Rapid and inexpensive drug susceptibility testing of Mycobacterium tuberculosis with a nitrate reductase assay
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DOI：
10.1128/jcm.40.2.553-555.2002
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发表时间：
2002-02-01
影响因子：
9.4
通讯作者：
Hoffner, SE
中科院分区：
文献类型：
--
作者：
Angeby, KAK;Klintz, L;Hoffner, SE
耐多药结核病是世界许多地区日益严重的公共卫生问题，特别是在低收入国家，大多数病例发生在这些国家。传统的药敏试验要么耗时，如固体培养基上的比例法，要么昂贵，如BACTEC 460系统。我们评估了一种新的硝酸还原酶测定法（NRA），它依赖于结核分枝杆菌将硝酸盐还原为亚硝酸盐的能力。可以使用产生颜色变化的特定试剂来检测减少。我们测试了一个57 M的面板。结核菌株具有不同的耐药模式。将细菌接种在Lowenstein-Jensen培养基上，不加药物或加利福平、异烟肼、链霉素或乙胺丁醇并加入硝酸钾（KNO 3）。培养7、10或14天后，加入试剂，通过颜色变化可以检测到硝酸盐还原，表明生长。与BACTEC 460方法相比，NRA方法对利福平的敏感性和特异性分别为100%和100%，异烟肼为97%和96%，链霉素为95%和83%，乙胺丁醇为75%和98%。大多数情况下，结果在7天内提供。该方法快速、经济，能正确鉴定大多数耐药和敏感M.结核菌株它有可能成为现有方法（如比例法和BACTEC方法）的一种令人感兴趣的替代方法，特别是在资源贫乏的环境中。
Multidrug-resistant tuberculosis is an increasing public health concern in many parts of the world, especially in low-income countries, where most cases occur. Traditional drug susceptibility testing is either time-consuming, such as the proportion method on solid media, or expensive, such as the BACTEC 460 system. We have evaluated a new nitrate reductase assay (NRA) that depends on the ability of Mycobacterium tuberculosis to reduce nitrate to nitrite. The reduction can be detected using specific reagents, which produce a color change. We tested a panel of 57 M. tuberculosis strains with various resistance patterns. The bacteria were inoculated on Lowenstein-Jensen medium, either without drugs or with rifampin, isoniazid, streptomycin, or ethambutol and with potassium nitrate (KNO3) incorporated. After incubation for 7, 10, or 14 days, the reagents were added and nitrate reduction, indicating growth, could be detected by a color change. Sensitivities to and specificities for drugs as determined by the NRA method compared to those determined by the BACTEC 460 method were 100 and 100% for rifampin, 97 and 96% for isoniazid, 95 and 83% for streptomycin, and 75 and 98% for ethambutol, respectively. The results were in the majority of the cases available in 7 days. The evaluated method is rapid and inexpensive and could correctly identify most resistant and sensitive M. tuberculosis strains. It has the potential to become an interesting alternative to existing methods, such as the proportion and BACTEC methods, particularly in resource-poor settings.