Yu Lu

The growing prevalence of multidrug-resistant Mycobacterium tuberculosis complicates tuberculosis control efforts. We discovered that Rv1453, as a new transcription factor, is crucial for lipid metabolism in bacteria. Rv1453 suppresses expression of genes related to fatty acid β-oxidation (fadD18, fadE5, fadE12, fadE13, fadE18, fadE30, fadE31, echA7) and genes for lipid synthesis (accA2, accD2). Furthermore, acyl-Coenzyme A influences signals regulated by Rv1453. Removing Rv1453 boosts expression of these genes, alters cell wall lipid composition, changes colony morphology, thickens the cell wall, and contributes to the reduced multidrug susceptibility. These findings point to an association between Rv1453-mediated lipid metabolism and multidrug sensitivity in Mycobacterium tuberculosis.

The increasing prevalence of drug-resistant Mycobacterium tuberculosis underscores the urgent need for novel therapeutic strategies. We found that the natural product chaetocin exhibits in vitro bactericidal activity against drug-sensitive and drug-resistant M. tuberculosis strains. Biochemical and genetic analyses revealed that chaetocin exerts its antibacterial activity by disrupting bacterial thiol-redox homeostasis, with the thioredoxin reductase TrxB2 as a key mediator. Chaetocin treatment leads to a disruption of cellular thiol-redox homeostasis and accumulation of lethal reactive oxygen species. Notably, modulation of TrxB2 expression directly altered bacterial susceptibility to chaetocin, indicating that TrxB2 is involved in the response to chaetocin. These findings establish chaetocin as an in vitro active compound and a promising lead for further investigation targeting bacterial redox homeostasis and provide a promising foundation for the development of a new class of anti-tuberculosis agents.

The persistent prevalence of multidrug-resistant tuberculosis (TB) and extensively drug-resistant TB has progressively undermined the efficacy of TB infect

Introduction: Tuberculous meningitis (TBM), the most severe form of Mycobacterium tuberculosis infection, is characterized by high mortality and neurological sequelae, largely attributed to blood-brain barrier (BBB) disruption. While recent studies identified GSDMD-mediated endothelial pyroptosis as a key mechanism of inflammatory BBB damage, the full molecular landscape in TBM remains unclear. Methods: This study employed an integrated multi-omics approach, combining bulk and single-cell RNA sequencing of clinical and murine datasets with experimental validation, to identify central mediators of BBB dysfunction in TBM. Results: We identified and validated three genes – MARCKS, CD274 (PD-L1), and IL17RA – as significantly upregulated in TBM. Single-cell analysis of a murine TBM model demonstrated predominant MARCKS expression in CNS microglia, a finding further supported by elevated MARCKS protein levels in peripheral blood mononuclear cells from patients. However, validation in human TBM brain tissue remains warranted. Functional enrichment and correlation analyses positioned MARCKS at the nexus of inflammatory signaling and cytoskeletal regulation, showing strong associations with key effectors of the GSDMD pyroptosis pathway (CASP4, CD14, NINJ1). Our data further indicate a robust co‑expression pattern between MARCKS and key effectors of the GSDMD pathway (CASP5, TLR4, and CASP1), suggesting that MARCKS‑mediated cytoskeletal destabilization and GSDMD‑dependent lytic pore formation may act in concert to promote BBB disruption. Nevertheless, this proposed mechanistic interplay requires direct experimental verification. Discussion: Our findings nominate MARCKS as a novel mechanistic hub linking neuroinflammation to barrier pathology in TBM, revealing potential therapeutic targets for adjunctive barrier‑stabilizing strategies.

Non-tuberculous mycobacteria (NTM) are ubiquitous in the natural environment. Globally, incidence of non-tuberculous mycobacterial disease is on the rise. To date, over 190 species of NTM have been identified, many of which possess inherent natural resistance to antibiotics, developing new drugs is a challenging process with a high risk of failure. The repurposing of existing drugs may be a quick and effective approach. This study investigates the combined effects of bedaquiline (BDQ) and nintedanib (a multi-target tyrosine kinase inhibitor) on NTM, with the aim of providing a novel therapeutic approach against NTM. The number of colony-forming units (CFUs) in macrophages was determined to assess the antibacterial activity of nintedanib against Mycobacterium avium and Mycobacterium abscessus. To evaluate the efficacy of nintedanib in combination with BDQ in a mouse model of pulmonary infection. The mechanism of the synergistic antibacterial effect of nintedanib and BDQ was investigated using assays of immune cells and immune factors, ATP measurement, transcriptomic sequencing and RT-PCR. Nintedanib significantly enhanced the intracellular antibacterial activity of BDQ against M. avium and M. abscessus. In mice infection model, nintedanib enhanced the efficacy of BDQ, reducing the extent of inflammatory damage and fibrosis in the mice’s lung tissue. The mechanism by which nintedanib enhances the antibacterial activity of BDQ is as follows: on the one hand, it boosts adaptive immunity in mice, promoting anti-inflammatory and tissue-repairing immune responses; on the other hand, it enhances BDQ’s ability to inhibit ATP production and disrupts bacterial metabolic pathways. In vitro and in vivo studies have shown that nintedanib enhances the antibacterial activity of BDQ, accelerates pathogen clearance and reduces lung damage. Nintedanib adjuvant therapy modulates the body’s adaptive immune response, promoting resolution of inflammation and tissue repair. Nintedanib may enhance the efficacy of BDQ by interfering with bacterial ATP synthesis and metabolic pathways. These findings highlight the potential of BDQ combined with nintedanib for the treatment of NTM infections and provide a crucial theoretical basis for the development of more effective therapeutic strategies for NTM infections.

Tuberculosis (TB), particularly drug-resistant tuberculosis (DR-TB), remains a critical global challenge and underscores the urgent need for novel drugs and innovative combination regimens with distinct mechanisms of action. Here, we characterize an all-oral three-drug regimen comprising TBI-166, bedaquiline(BDQ), and pyrazinamide(PZA), which displays strong synergistic antimicrobial activity in vitro against both replicating and non-replicating Mycobacterium tuberculosis (MTB) and has previously shown superior bactericidal and sterilizing efficacy to standard HRZ and BPaL regimens in murine TB models(1). Time-kill studies demonstrate that the triple regimen outperforms dual-drug combinations, accelerating bacterial clearance across multiple physiological states. Mechanistic investigations revealed that the TBI-166–BDQ–PZA combination induces a comprehensive collapse of energy and redox homeostasis, marked by profound ATP depletion, robust accumulation of reactive oxygen species (ROS), and marked disruption of the intracellular NAD(H) pool. TBI-166, a novel riminophenazine analogue of clofazimine (CFZ) currently in phase II clinical trials, emerged as a key contributor to this metabolic stress. Metabolomic profiling and ¹³C-based flux analysis show that TBI-166 slows glycolysis and the tricarboxylic acid (TCA) cycle while enhancing flux through the pentose phosphate and nicotinate pathways, thereby lowering the NADH/NAD⁺ ratio and diminishing MTB metabolic flexibility under environmental stress. In parallel, TBI-166 downregulates the dormancy regulator DosR and its regulon, further compromising adaptation to non-replicating states. Multi-omics analyses, together with biochemical and biophysical assays, identify the pyruvate dehydrogenase complex (PDHc) components DlaT and LpdC as direct molecular targets of TBI-166, with drug binding leading to potent inhibition of their enzymatic activities. Collectively, these findings define the mechanism of action of TBI-166 and provide a molecular rationale for its inclusion in potent, all-oral, short-course regimens. More broadly, they highlight the therapeutic potential of metabolically targeted combinations that destabilize energy metabolism, redox balance, and metabolic adaptability to improve DR-TB treatment outcomes.

Tuberculous meningitis (TBM) is the most severe form of tuberculosis (TB) with high mortality. This study evaluated the cerebrospinal fluid (CSF) concentration and safety of the novel oxazolidinone contezolid compared to linezolid in TBM patients. In this randomized prospective study, 10 TBM patients received either a linezolid-containing ( n = 5) or contezolid-containing ( n = 5) anti-TB regimen. CSF and blood concentrations were measured at 2 and 6 h post-dose. Peak (2 h) and trough (6 h) concentrations, area under the concentration-time curve (AUC), and safety were assessed. Contezolid CSF concentrations exceeded the Mycobacterium tuberculosis (Mtb) MIC (0.5 μg/mL) at 2 h (median: 1.0806 μg/mL, range: 0.9295–1.3165 μg/mL) but declined by 6 h (median: 0.7920 μg/mL, range: 0.1867–1.0194 μg/mL). Linezolid CSF concentrations were significantly higher than contezolid at both 2 h (median: 3.251 μg/mL, range: 1.9545–4.9636 μg/mL; P = 0.008) and 6 h (median: 1.623 μg/mL, range: 0.941–1.765 μg/mL; P = 0.016), remaining above MIC in all samples at 6 h. The mean CSF AUC for contezolid (4.637 μg·h/mL, 95% CI: 3.599–5.675) was significantly lower than that for linezolid (12.537 μg·h/mL, 95% CI: 7.8797–17.277; P = 0.008). Blood concentrations were higher than CSF for both drugs at all time points. No serious drug-related adverse events occurred. Contezolid effectively penetrates the blood-CSF barrier in TBM patients, achieving CSF concentrations above the MIC for Mtb. Although its CSF exposure was significantly lower than linezolid, its demonstrated penetration and safety profile suggest contezolid warrants further investigation as a potential treatment option for drug-resistant TBM. IMPORTANCE: Tuberculous meningitis (TBM) is the deadliest form of tuberculosis, especially difficult-to-treat drug-resistant TBM. Finding new, effective, and safe medicines is critical. This study provides evidence in TBM patients that a newer antibiotic, contezolid, successfully reaches the infection site in cerebrospinal fluid (CSF) at levels expected to kill Mycobacterium tuberculosis . While linezolid achieved higher levels in CSF, contezolid still reached concentrations predicted to be effective and caused no serious side effects in our study. This is important because contezolid might offer a safer alternative to linezolid, which can have significant long-term toxicity. These promising results suggest contezolid could become a valuable new weapon against refractory drug-resistant TBM, potentially saving lives where current options are limited or too toxic.

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a major global health threat, particularly due to the rise of multidrug-resistant TB (MDR-TB). Current treatment limitations highlight the urgent need for new therapeutics to improve efficacy and shorten therapy duration. Through high-throughput screening, we identified Questiomycin A (QM), a phenoxazinone compound with promising anti-tuberculosis activity against drug-sensitive and drug-resistant Mtb strains. Transcriptomic profiling indicated disruption of cell wall-associated pathways, while thermal proteome profiling showed that QM binding substantially increased the thermal stability of FabD (malonyl CoA-acyl carrier protein transacylase, MCAT), a key enzyme in mycolic acid biosynthesis. Surface plasmon resonance, enzymatic assays, and genetic manipulation confirmed QM directly binds to and inhibits FabD. This inhibition damages cell wall integrity, increases permeability, disturbs intracellular pH homeostasis, and collapses the proton motive force, ultimately leading to bacterial death. Pharmacokinetic evaluation in six-week-old male Balb/c mice following a single oral dose demonstrates rapid absorption but limited drug exposure. Together, these findings reveal that QM targets FabD to compromise cell wall homeostasis in Mtb, providing a foundation for developing novel anti-tubercular agents targeting FabD.

Linezolid is an important drug for the treatment of drug-resistant tuberculosis (DR-TB). Acquired linezolid resistance threatens treatment efficacy. This s