Transposon-based strategies provide a powerful and unbiased way to study the bacterial stress response^{1,2,3,4,5,6,7,8}, but these approaches cannot fully capture the complexities of network-based behaviour. Here, we present a network-based genetic screening approach: the transcriptional regulator-induced phenotype (TRIP) screen, which we used to identify previously uncharacterized network adaptations of Mycobacterium tuberculosis to the first-line anti-tuberculosis drug isoniazid (INH). We found regulators that alter INH susceptibility when induced, several of which could not be identified by standard gene disruption approaches. We then focused on a specific regulator, mce3R, which potentiated INH activity when induced. We compared mce3R-regulated genes with baseline INH transcriptional responses and implicated the gene ctpD (Rv1469) as a putative INH effector. Evaluating a ctpD disruption mutant demonstrated a previously unknown role for this gene in INH susceptibility. Integrating TRIP screening with network information can uncover sophisticated molecular response programs.

基于转座子的策略提供了一种强大且公正的方法来研究细菌应激反应^{1,2,3,4,5,6,7,8}，但这些方法不能完全捕捉基于网络的行为的复杂性。在这里，我们提出了一种基于网络的遗传筛选方法：转录调节诱导表型 (TRIP) 筛选，我们用它来识别以前未表征的结核分枝杆菌对一线抗结核药物异烟肼 (INH) 的网络适应性。我们发现了在诱导时改变 INH 易感性的调节剂，其中一些无法通过标准基因破坏方法鉴定。然后，我们专注于一种特定的调节剂mce3R，它在被诱导时会增强 INH 的活性。我们比较了 mce3R- 具有基线 INH 转录反应的调节基因，并暗示基因ctpD (Rv1469) 作为推定的 INH 效应子。评估ctpD破坏突变体证明了该基因在 INH 易感性中的先前未知作用。将 TRIP 筛选与网络信息相结合可以发现复杂的分子反应程序。