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Truebody, B.

Publications and source records attributed to Truebody, B..

2 recordsLinked to original sources

Menaquinone depletion resensitises bedaquiline-resistant tuberculosis

Tuberculosis remains a leading cause of global mortality, and rising bedaquiline resistance threatens the effectiveness of current drug-resistant treatment regimens. Bedaquiline resistance typically arises through mutations in Rv0678 that upregulate drug efflux and confer cross-resistance to multiple drug classes. Here, we identify and optimise a chemical series targeting MenG, a central enzyme in the menaquinone biosynthesis pathway, yielding potent bactericidal inhibitors with in vivo efficacy. Strikingly, MenG inhibition restored bedaquiline susceptibility in efflux-mediated resistant strains, an effect confirmed in vivo where combination therapy achieved a 99.8% reduction in bacterial burden compared with bedaquiline alone. Potentiation also extended to pretomanid and other key agents. Disruption of upstream menaquinone and shikimate pathway enzymes produced similar resensitisation, establishing these pathways as tractable targets for restoring drug susceptibility in Mycobacterium tuberculosis. These findings provide a novel strategy to overcome bedaquiline resistance and strengthen future regimens for efflux-mediated drug-resistant tuberculosis.

microbiology↗

Mycobacterium tuberculosis senses host Interferon- gamma via the membrane protein MmpL10

Mycobacterium tuberculosis (Mtb) is one of the most successful human pathogens and remains a leading cause of death from infectious disease. Interferon-{gamma} (IFN-{gamma}) is a central regulator of the immune defense against Mtb. Several cytokines have been shown to increase virulence of other bacterial pathogens, leading us to investigate whether IFN-{gamma} has a direct effect on Mtb. We found that both recombinant and T-cell derived IFN-{gamma} rapidly induced a dose-dependent increase in the oxygen consumption rate (OCR) of Mtb, consistent with increased bacterial respiration. This was also observed in clinical strains, but not in the vaccine strain Bacillus Calmette-Guerin (BCG), and did not occur for other cytokines tested, including TNF-. IFN-{gamma} binds to the cell surface of intact Mtb, but not BCG, whilst TNF- binds to neither. Mass spectrometry analysis identified mycobacterial membrane protein large 10 (MmpL10) as the transmembrane binding partner. Consistent with this, IFN-{gamma} binding and the OCR response was absent in a Mtb {Delta}mmpl10 strain and restored by complementation of the mutant strain. RNA-sequencing of IFN-{gamma} exposed Mtb revealed a distinct transcriptional profile, including genes involved in virulence and cholesterol catabolism. Finally, exposure of Mtb cells to IFN-{gamma} resulted in sterilization of bacilli treated with isoniazid (INH), indicating clearance of phenotypically resistant bacteria that persist in the presence of INH alone. Our data suggest a novel mechanism allowing Mtb to respond to host immune activation that may be important in the immunopathogenesis of TB and have use in novel eradication strategies. One-Sentence SummaryIFN-{gamma} is a critical component of effective immune defense in human tuberculosis yet its causative agent, Mycobacterium tuberculosis it able to sense this cytokine and increase virulence and respiration in response.

microbiology↗