Orthogonal perturbation of sulfur availability reveals antibiotic-induced synthetic lethality in Mycobacterium tuberculosis

Despite its essential role in growth, the impact of sulfur limitation on mycobacterial physiology and antibiotic responsiveness remains poorly understood. Here, we combined chemical-genetic perturbations and infection models to investigate the consequences of sulfur limitation in Mycobacterium tuberculosis (M. tuberculosis). We report that sulfur limitation restricted bacterial growth by rewiring metabolism, resembling nutrient starvation. CRISPR interference of the sulfate transporter (ST) revealed severe vulnerability and sensitised M. tuberculosis to anti-TB drugs. Inhibition of H2S production in macrophages further compromised the fitness of ST-deficient M. tuberculosis, indicating that the bacteria depend on host-derived sulfur during infection. Importantly, preventing sulfur acquisition attenuated both the drug-sensitive H37Rv and the drug-resistant clinical strain of M. tuberculosis, while enhancing the efficacy of Isoniazid (INH) in the murine model, resulting in sterilisation of infected lung tissues. Combined, our findings suggest that restricting sulfur uptake highlights a therapeutic vulnerability that enhances the efficacy of existing anti-TB drugs.