Drug resistance has become a serious public health problem in mycobacterial infectious diseases. Here, we investigated a water soluble tetrazolium salt (EZMTT)-based detection method to provide an easy, safe and quantitative antimycobacterial susceptibility test (AMST) method, especially for targeting early detection of loss of drug susceptibility in mycobacteria. After a single addition of the EZMTT detection reagent at the inoculation of mycobacteria culture, the AMST was continuously analyzed in a sealed 96-well plate (100 μl), or a sealed tube to ensure biosafety. Using Mycobacterium tuberculosis H37Ra as the model strain, the EZMTT assay was developed with high reproducibility (Z factor of 0.64) for facile measurements of growth and drug susceptibility. In the comparative AMST study, the 7-day EZMTT method identified not only the same set of drug resistance as the other two methods (the 30-day traditional Löwenstein Jensen solid medium assay and the 10–14 day 8 ml Mycobacteria Growth Indicator Tube liquid method), but also additional strains with loss of drug susceptibility. In conclusion, we demonstrated that the EZMTT-based AMST assay in a sealed microtiter plate has great potential for routine use in medical diagnosis and drug screening to battle the unmet medical need in the treatment of multi- and extensive-drug resistant mycobacteria.

耐药性已成为分枝杆菌感染性疾病中严重的公共卫生问题。在这里，我们研究了一种基于水溶性四唑盐 (EZMTT) 的检测方法，以提供一种简单、安全和定量的抗分枝杆菌药敏试验 (AMST) 方法，特别是针对分枝杆菌药物敏感性丧失的早期检测。在接种分枝杆菌培养物时单次添加 EZMTT 检测试剂后，在密封的 96 孔板 (100 μl) 或密封管中连续分析 AMST，以确保生物安全。使用结核分枝杆菌H37Ra 作为模型菌株，EZMTT 检测具有高重现性（Z 因子为 0.64），可轻松测量生长和药物敏感性。在比较 AMST 研究中，7 天 EZMTT 方法不仅识别出与其他两种方法（30 天传统 Löwenstein Jensen 固体培养基测定和 1​​0-14 天 8 ml 分枝杆菌生长指示管液体）相同的一组耐药性方法），但也有失去药物敏感性的其他菌株。总之，我们证明了密封微量滴定板中基于 EZMTT 的 AMST 测定在医学诊断和药物筛选中的常规应用方面具有巨大的潜力，以应对治疗多重和广泛耐药分枝杆菌中未满足的医疗需求。