ATP burst is the dominant driver of antibiotic lethality in Mycobacteria

Abstract

AbstractAntibiotic-tolerant bacteria, due to their unique physiology, are refractory to antimicrobial killing and pose challenges for infection control. Incomplete knowledge of how bactericidal antibiotics work limits our understanding of partial resistance from phenotypic tolerance in mycobacteria, a driver for developing genetic resistance. Using proteomics,13C isotopomer analysis, and biochemical assays, we investigated the physiological response ofM.smegmatischallenged with aminoglycoside and fluoroquinolone antibiotics. Two distinct classes of antibiotics elicited remarkably similar responses and increased flux through the TCA cycle, causing enhanced respiration, ROS generation, and ATP burst. We found that ATP burst drives cidality through metal ion chelation, which was rescued by exogenous supplementation with divalent metals.13C isotope tracing indicated TCA cycle flux deviation from its oxidative arm as a bacterial adaptive mechanism, which also included activated intrinsic resistance and a higher propensity to develop antibiotic resistance. Our study provides a new understanding of the intricate mechanisms of antibiotic-induced cell death and expands the current paradigm for antibiotic action.