Synthetic lethality of <i>Mycobacterium tuberculosis</i> NADH dehydrogenases is due to impaired NADH oxidation

Importance In 2022, it was estimated that 10.6 million people fell ill, and 1.6 million people died from tuberculosis (TB). Available treatment is lengthy and requires a multi-drug regimen, which calls for new strategies to cure Mycobacterium tuberculosis ( Mtb ) infections more efficiently. We have previously shown that simultaneous inactivation of type 1 (Ndh-1) and type 2 (Ndh-2) NADH dehydrogenases kills Mtb . NADH dehydrogenases play two main physiological roles: NADH oxidation and electron entry into the respiratory chain. Here, we show that this bactericidal effect is a consequence of impaired NADH oxidation. Importantly, we demonstrate that Ndh-1/Ndh-2 synthetic lethality can be achieved through simultaneous chemical inhibition, which could be exploited by TB drug development programs.