Latent tuberculosis infection (LTBI), characterized by the host immune system's ability to contain Mycobacterium tuberculosis (MTB) proliferation while failing to fully eliminate the pathogen, is a critical stage in tuberculosis prevention and control. Macrophages and alveolar epithelial cells together constitute the first line of defense. Following infection, MTB triggers a series of responses in which miRNAs, in concert with other biomolecules, coordinately regulate macrophage polarization, autophagic activity, the key metabolic pathways of autophagy, and the inflammatory response of host macrophages. This review summarizes the core mechanisms by which MTB exploits miRNAs to regulate host macrophage polarization, autophagy, and immunity, encompassing both the specific pathways that promote LTBI through autophagy inhibition and the induction of immunosuppressive phenotypes, and the shared mechanisms by which MTB disrupts host antimicrobial immunity during active tuberculosis.

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a global public health challenge. Rapid and accurate diagnostic methods are critical for effective TB control. In recent years, serological diagnosis has attracted growing attention with the continuous identification of novel biomarkers, owing to its simplicity, rapid turnaround, and cost-effectiveness, particularly for the diagnosis of extrapulmonary TB (EPTB) and in individuals who test negative by sputum culture and rapid molecular assays. In this review, we summarize current biomarkers used in TB serodiagnosis, discuss the integration of advanced diagnostic technologies, and highlight their potential to improve TB diagnosis across diverse clinical settings.

Elucidating the structural basis of Fgd1-mediated resistance to Delamanid in Mycobacterium tuberculosis.

Tuberculosis (TB) is a major global health issue worsened by drug-resistant isolates. This study presents a detailed in silico investigation of isoscopoletin by combining quantum-chemical calculations, pharmacokinetic profiling, molecular docking, and molecular dynamics simulations against the Mycobacterium tuberculosis target protein thymidylate kinase. Structural stability was established by geometry optimization using density functional theory (DFT) at the APFD/6-311+G(2d,p) level of theory. The optimized molecular geometry was used to obtain HOMO-LUMO energies, chemical reactivity descriptors and molecular electrostatic potential (MEP). Frontier molecular orbital analysis showed a small HOMO-LUMO energy gap of 4.3 eV, indicating high reactivity, while molecular electrostatic potential (MEP) mapping highlighted reactive nucleophilic and electrophilic regions. Topology analyses, such as ELF, LOL, RDG, NCI, frontier orbital analysis, and molecular electrostatic potential mapping, were all insightful for charge distribution and non-covalent interactions. Pharmacokinetic and ADMET profiling demonstrated favorable drug-likeness, with a TPSA of 59.67 Å2 and a bioavailability score of 0.55. Molecular docking suggested strong binding affinity, which was further validated by 200 ns molecular dynamics simulations. The protein-ligand complex exhibited stable RMSD values ranging from 1.0 to 2.6 Å (average ≈ 1.8 Å) compared to the free protein (1.8-3.0 Å; average ≈ 2.4 Å), indicating enhanced stability upon ligand binding. RMSF analysis showed minimal residue fluctuations (0.05-0.20 nm), while the radius of gyration remained stable between 1.60 and 1.72 nm. Principal component analysis revealed that the first three components (PC1: 26.16%, PC2: 14.45%, PC3: 9.14%) accounted for 49.8% of the total motion, indicating coordinated and stable dynamics. These computational findings demonstrate that isoscopoletin exhibits favorable electronic properties, stable protein-ligand interactions, and good pharmacokinetic characteristics, supporting its application as an anti-tubercular drug.

Tuberculosis (TB), a disease caused by Mycobacterium tuberculosis, remains one of the major causes of death from infection worldwide, with over a million associated deaths each year. The study of biomarkers for TB is critical for advancing our understanding and management of the disease. Biomarkers, defined as measurable indicators of biological states or conditions, are invaluable for the diagnosis, prognosis and treatment monitoring of TB. Clinical studies have provided critical knowledge on the matter but are also notoriously constrained by economical, ethical and sampling limitations. The use of animal models provides a simpler, more controllable, cost-effective setting with great potential for translation to humans. They also allow the evaluation of biomarkers within the respiratory compartment, when available, which is of particular interest due to the nature of TB pathogenesis. This Review focuses on the current landscape of TB biomarker discovery in several animal models, from invertebrates to large mammals. Here we summarize the basics of host-pathogen immune interaction, describe the main methodological approaches used and highlight the most substantial findings for each animal model studied. Furthermore, we discuss the advantages, challenges and limitations associated with species-specific differences in animal models. We conclude that integrating the data obtained from animal models and human studies is absolutely required to advance the TB field to accelerate the management of this disease.

A roadmap for rapid detection of tuberculosis through microfluidic lab-on-chip strategies.

A fusion protein LT25 containing Rv2660c failed to provide protection against Mycobacterium bovis infection due to limited humoral immune responses.

Treatments for tuberculosis disease (TB) are failing on a global scale, necessitating new drug discovery efforts to identify effective therapies. Mycobacterium tuberculosis (Mtb), the obligate human pathogen and causative agent of TB, resides within alveolar macrophages and combats acidic stress by inhibiting phagosome maturation. Understanding the role of acidification in Mtb pathogenesis can aid the development of improved TB therapies. Aligning with the hypothesis that acidification affects Mtb intracellular survival, we developed a phenotypic assay to identify compounds that enhance acidification of Mtb in infected macrophages. To evaluate the assay suitability for screening purposes, we screened two compound libraries and found that early acidification does not necessarily correlate with inhibition of Mtb growth over time. Further, we found that compounds interfering with bacterial protein and DNA synthesis induced early phagosome acidification. However, other compounds, including cell wall synthesis inhibitors, did not consistently correlate with acidification or growth inhibition. Using early acidification could therefore provide a potential avenue to inform antimicrobial kinetics. By assessing Mtb's response to phagosome acidification, this work highlights the complexity of host-pathogen interactions in early infection and provides a valuable tool for investigating Mtb survival mechanisms and accelerating drug discovery efforts.

Mycobacterium tuberculosis Rv3875 upregulates TRIM21 expression through the type I interferon/STAT1 pathway and promotes intracellular growth.

The widespread use of fluoroquinolone antibiotics to treat Mycobacterium tuberculosis (Mtb) infections has led to a rise in fluoroquinolone-resistant Mtb strains, mainly due to specific mutations in the target DNAgyrase. To overcome this resistance and develop treatment alternatives, a deeper understanding of fluoroquinolone's mechanism of action is necessary. In this study we performed molecular dynamics (MD) simulations on experimentally derived complexes of wild-type and Ala90Ser mutated Mtb DNA gyrase with three fluoroquinolones - moxifloxacin, gatifloxacin, and levofloxacin. The differences in binding among the three drugs and the impact of the Ala90Ser mutation were analyzed at molecular level. Key interactions between gyrase amino acids, DNA nucleotides, and Mg2+ cofactor with the fluoroquinolone ligands, were identified. The ranking of fluoroquinolones according to the stability of their DNA-gyrase complexes, binding energies, and key binding site residues, was in accordance with the in vitro reversibility assay data and the clinical effects of the drugs, thus validating the obtained MD results. Overall, our study contributes to a better understanding of the molecular mechanisms underlying fluoroquinolone activity, and demonstrates the potential of the MD simulations to predict the drugs' behavior within Mtb DNA-gyrase complexes.

rBCG::PUMA exhibits enhanced immunogenicity compared to BCG in mice.

Early clearance of Mycobacterium tuberculosis among Indonesian household contacts is not associated with circulating beta-glucan present at the time of exposure.

Pyrvinium pamoate inhibits the survival of intracellular Mycobacterium tuberculosis through suppression of macrophage ferroptosis.

Mycobacterium tuberculosis MEM39 (Rv1977) hijacks host aldolase A (ALDOA) to subvert immunometabolism to facilitate bacterial intracellular survival.

Mycobacterium tuberculosis bacteraemia is a severe manifestation of tuberculosis in people living with human immunodeficiency virus acquired immune deficiency syndrome, associated with high mortality. We found patients with fatal outcomes had significantly lower lymphocyte, platelet, and CD4+ T-lymphocyte counts, and higher urea levels (p < 0.05). CD4+ T-lymphocyte count <32 cells/mm3 was independently associated with mortality (p = 0.005). The oral rifampicin, isoniazid, pyrazinamide, and ethambutol regime was more frequent among survivors. Social vulnerability factors were common but not independently associated with mortality.

The study addresses the increasing resistance to the FDA-approved drug Bedaquiline (BDQ) in Mycobacterium tuberculosis (MTB). The absence of any defined resistance locus and the wide variation in the drug targets across clinical isolates have raised a big question about our understanding of the molecular basis of BDQ resistance acquisition. Using machine learning (ML) methods, BDQ resistance was predicted from whole-genome sequencing data for MTB clinical isolates. Variant calling format data generation involved several steps, including adapter trimming and alignment to the H37Rv reference genome. The ML models, namely, Multilayer Perceptron and Random Forest (RF), achieved high accuracies of 83.60% and 79.64%, respectively. The top 50 features were mapped to the H37Rv reference genome, and several new drug targets were identified. In addition to the coding regions, some non-coding intergenic regions were also obtained. Mapping of these features to the H37Rv genome revealed 15 new antibiotic-resistant genes. In addition, the use of explainable AI (XAI) methods, such as SHapley Additive exPlanations, facilitated the identification of mutations associated with BDQ resistance. In conclusion, the ML models demonstrated effective predictive capabilities for BDQ resistance, whereas XAI contributed to understanding key resistance features.

Discovery and identification of a handwritten laboratory notebook by Albert Calmette and Camille Guérin describing experimental studies and development of the BCG vaccine for tuberculosis at the Institut Pasteur.

Using droplet digital polymerase chain reaction for cell-free DNA to diagnose tuberculous pleural effusion.

The drug-resistant profile of tuberculosis (TB) varies across geological regions. This study aimed to evaluate the association of katG, inhA, and AhpC mutations with isoniazid (INH) resistance of Mycobacterium tuberculosis in pulmonary TB patients from Nanjing, China. Laboratory and genetic data of INH-resistant genes in TB patients living in Nanjing and hospitalized in the Department of Tuberculosis, the Second Hospital of Nanjing, from January 2019 to December 2021 were retrospectively analyzed. A total of 1,712 human M. tuberculosis strains (1,308 INH-sensitive and 404 INH-resistant) were identified by phenotypic drug susceptibility testing (DST). Mutations were detected in katG315, the inhA promoter region, and the AhpC promoter region. Among the 172 INH-resistant strains identified by phenotypic DST, 159 samples of gene mutations were detected. The mutation rate in katG315 in INH-resistant strains was significantly higher than those in the inhA promoter region and AhpC promoter region. The rate of INH resistance was higher in M. tuberculosis strains with the katG315 mutation combined with the inhA/AhpC promoter region mutations than in those with a single mutation in katG315. The incidence of the katG315 mutation in multidrug-resistant TB patients and pre-extensively drug-resistant (pre XDR) TB patients was significantly higher than that in INH-resistant TB patients. The rate of katG315 mutation combined with the inhA/AhpC promoter region mutation was higher in pre XDR-TB patients. The katG315 mutation, or its combination with inhA/AhpC promoter region mutations, may be the main cause of INH resistance of M. tuberculosis strains in TB patients from Nanjing, China.

Emerging therapeutic paradigms in tuberculosis: Nanocarriers, host-directed strategies, and translational pharmacology.