BACKGROUND:The Bacille Calmette-Guérin (BCG) vaccine against tuberculosis is the most widespread vaccine in the world. Discovered by French investigators Albert Calmette and Camille Guérin at the Pasteur Institute, it remains the only effective vaccine against tuberculosis infection. This report describes the recognition and identification of a previously unknown French handwritten laboratory notebook prepared by Drs. Calmette and Camille Guérin recording their experiments performed during the development of the BCG vaccine. METHODS:The notebook was examined, translated into English, photographed and the experiments analyzed. RESULTS:The manuscript laboratory notebook consists of 69 leaves written in 2 hands, one of which corresponds to that of Albert Calmette. It contains details of experiments that were performed during the development of the BCG vaccine at the Pasteur Institute by Drs. Calmette and Guérin. These include experimental inoculations of rabbits and guinea pigs; descriptions of the pathology of skin lesions, inflammatory reactions, and organ pathology; and survival outcome. The experiments describe varying inoculative dosages of the bacteria, and different routes of administration including intraperitoneal and subcutaneous injections, and administration of bacilli in the ear. In those cases where the animal had died following inoculation of tubercle bacilli, necropsy was performed and the organs examined and the pathology findings described. Details of culture experiments and vaccine passage are listed. CONCLUSIONS:This previously unknown notebook is a highly organized and detailed record of investigations using tuberculosis in animal experiments and microbiological culture to produce a safe and effective vaccine, first used in humans in 1921.
OBJECTIVE:The aim of the study was to determine the associations between vitamin D (VD) and cytokine levels in active pulmonary tuberculosis (PTB) patients with chronic pulmonary aspergillosis (CPA). METHODS:One hundred seventy-two active PTB patients, twenty-eight PTB patients with CPA (PTB-CPA), and sixty healthy subjects were included in the study. The concentrations of serum 25-hydroxyvitamin D, interleukin (IL)-1β, IL-4, IL-6, IL-8, IL-10 and tumor necrosis factor (TNF-α) were measured by ELISA. RESULTS:A significantly lower VD level was detected in PTB-CPA patients (14.96 ± 10.89 ng/mL) than in both PTB patients (20.72 ± 8.07 ng/mL, p < 0.01) and controls (23.90 ± 8.16 ng/mL, p < 0.001). VD deficiency was significantly more prevalent in PTB-CPA patients than in PTB patients (OR = 2.86, 95% CI: 1.22-6.69; p = 0.01) or controls (OR = 5.33, 95% CI: 2.02-14.11; p = 0.0005). In the PTB group, VD levels exhibited a significant inverse correlation with only IL-6 (r = -0.376, p = 0.0001), whereas in PTB-CPA patients, stronger inverse correlations were observed with IL-6 (r = -0.691, p = 0.0005) and IL-8 (r = -0.538, p = 0.01). In cavitary PTB patients, a significant inverse link was found between VD and IL-1β and IL-6 levels (all p ≤ 0.05). CONCLUSION:Our data revealed a high prevalence of VD deficiency in all groups, predominantly in PTB-CPA patients. The inverse correlations between VD levels and IL-6 and IL-8 levels in PTB-CPA patients as well as between VD and IL-1β and IL-6 levels in cavitary PTB patients, provide further evidence for the role of VD as a regulator of inflammatory pathways in the context of coinfection.
A significant proportion of individuals heavily exposed to infectious tuberculosis patients do not acquire Mycobacterium tuberculosis (Mtb) infection, as detected by an interferon gamma release assay (IGRA). Trained immunity may contribute to this host resistance to Mtb infection, also termed early clearance. From a prospective tuberculosis household study in Indonesia we selected 80 heavily exposed IGRA-negative household contacts, of whom 40 converted their baseline-negative IGRA to positive after three months (IGRA converters) and 40 remained IGRA-negative (early clearers). From all individuals we measured circulating β-D-glucan and used their serum for induction of trained immunity in vitro, using peripheral blood mononuclear cells from healthy unexposed Dutch donors, that were stimulated with unrelated stimuli six days after exposure to serum from household contacts. β-D-glucan concentrations and positivity did not correlate with early clearance, nor with serum-induced in-vitro trained immunity as measured by heterologous cytokine responses. These findings suggest that early clearance is unlikely to be maintained by circulating β-D-glucan or other serum factors present at exposure to Mtb, and may instead depend on cell-intrinsic or local host processes not captured by serum-based assays.
Background Type 2 diabetes mellitus elevates the risk of developing tuberculosis, posing a substantial challenge to TB treatment and control. However, the underlying molecular mechanisms remain poorly understood. Methods Non-targeted metabolomics analysis of serum samples collected from 20 patients with concurrent DM and TB (DM-TB) and 20 patients with TB only (TB) was performed using UPLC-MS/MS. Logistic regressions were applied to evaluate the associations between the metabolites and lung pathology. Results Pathway analysis revealed that TCA cycle, steroidogenesis, ketone body metabolism were the key pathways enriched in the differential metabolites distinguishing DM-TB from TB patients. Multivariable logistic regression analysis suggested, high levels of C18 Sphingosine (OR = 2.207, 95% CI = 1.049-4.645), L-Saccharopine (OR =4.407, 95% CI = 1.045-18.582) and arachidonic acid (AA) (OR = 2.845, 95% CI = 1.272-6.366) were associated with an increased risk of extensive lung lesions. In addition, C18 Sphingosine (OR = 3.596, 95% CI = 1.239-10.440) and AA levels (OR = 3.306, 95% CI = 1.200-9.112) were positively associated with the risk of prevalent multiple cavities. Conclusions Our results suggests that lipid metabolism disorders are significantly associated with severe lung lesions in TB-DM patients, suggest a potential link to exacerbated inflammatory and immunomodulatory responses.
Rv2660c is present in both Mycobacterium tuberculosis (M. tuberculosis) and Mycobacterium bovis (M. bovis) and has been reported as a protective antigen. In this study, Rv2660c was linked with another M. tuberculosis specific antigen Rv2645, which is present in M. tuberculosis but not in M. bovis, to construct a fusion protein Rv2645-Rv2660c (LT25 in short). LT25 failed to confer protection following M. bovis challenge. Structural predictions via AlphaFold 3 revealed that LT25 retained the native conformation of Rv2645, whereas Rv2660c underwent significant conformational alterations. LT25 elicited strong Rv2645 and Rv2660c-specific cellular immune responses and high levels of Rv2645-specific antibodies, but lower levels of Rv2660c-specific antibodies than Rv2660c did. Further investigation showed that the Rv2660c-induced polyclonal antibody possessed stronger phagocytosis-promoting activity than LT25-induced antibodies did. These findings suggest that the structural integrity of Rv2660c is essential for its protective function.
Bovine tuberculosis (bTB), caused by Mycobacterium bovis, remains a major zoonosis impacting livestock productivity and public health. To characterize species-specific immune responses and identify transcriptional biomarkers of infection, we quantified the expression of 45 immune-related genes in peripheral blood from naturally infected cattle and Mediterranean buffalo.Differential and multivariate analyses revealed distinct species- and state-specific transcriptional signatures. Sixteen genes were significantly modulated in cattle, with Canonical Discriminant Analysis (CDA) defining a promising diagnostic signature marked by upregulation of IFNG, CASP8, CASP1, and CD83, and downregulation of IL10, CXCR2, and MMP9. In buffaloes, 22 genes were differently expressed across the three clinical groups. The first canonical function (Can1), driven positively by IFNG and IL12B and negatively by MMP9 and TLR5, effectively separated healthy from infected and affected animals, while the second function (Can2) distinguished the affected status through marked upregulation of CXCL1 and IL6.The species-specific immune signatures uncovered underscore the importance of developing tailored biomarker panels for improved diagnosis and surveillance of bTB in different livestock species.
Tuberculosis (TB) is still a serious global public health problem, affecting mostly vulnerable populations such as the population deprived of liberty (PDL). Brazil has the third-largest prison population in the world, and the state of São Paulo has the largest PDL in the country. This study investigated the molecular epidemiology of TB in individuals from the general population (GP) and the PDL belonging to two Epidemiological Surveillance Groups in the state of São Paulo. A total of 522 Mycobacterium tuberculosis isolates were analyzed using MIRU-VNTR genotyping (15 and 24-loci) and multiplex PCR for detection of RDRio/RD174 deletions. Clustering rates were 14.7% for 15-loci and 12.8% for 24-loci. The RDRio sublineage was identified in 26.8% of isolates, showing an association with alcohol use disorder (OR = 1.84; 95% CI 1.17-2.88) and illiteracy (OR = 3.40; 95% CI 1.09-10.58). Clusters with 100% similarity between GP and PDL isolates were observed, indicating intra- and extramural transmission within prison units. These findings highlight the importance of integrated surveillance and control strategies, with strengthened active case finding in both populations, in order to interrupt transmission chains and reduce the TB burden. In addition, further high-resolution genomic studies involving the PDL are recommended, focusing on complete genome sequencing integrated with epidemiological, spatial, and socio-environmental data, which will contribute to the improvement of TB surveillance and control strategies in highly vulnerable contexts.
Drug tolerance in Mycobacterium tuberculosis (Mtb) significantly undermines the success of antimycobacterial therapy. Redox active compounds such as Vitamin C (VitC) and iron can modulate drug efficacy, and in the present study we evaluated their effect on Rifampicin (RIF) mediated killing of Mycobacterium tuberculosis H37Ra (Mtb-Ra). We also studied the cellular reactive oxygen species (ROS) levels and expression of stress-response and drug target genes, and host cell cytotoxicity. ROS measurements revealed that treating Mtb-Ra with RIF and VitC led to ROS levels mostly being elevated, with iron supplementation leading to further increase. Survival analysis showed that VitC increased the killing by RIF in a dose-dependent manner, with iron potentiating this effect. Cytotoxicity studies showed that high iron and its combinations with VitC and RIF showed comparable cytotoxicity. The qRT-PCR study demonstrated RIF induced up-regulation of recA, dnaE2 and rpoB with VitC and iron, further amplifying recA and dnaE2 expression. Conversely, lexA was down-regulated in the presence of VitC and more strongly with iron, indicating induction of bacterial SOS response. Interestingly, rpoB expression, while up-regulated with RIF and VitC, was suppressed by iron. These findings suggest that VitC and iron-induced disruption of Mtb homeostasis can enhance RIF efficacy.
Tuberculosis (TB) is a curable infectious disease that requires prolonged treatment with multiple antibiotics. To better understand how the immune system contributes to the clearance of Mycobacterium tuberculosis (Mtb), in vitro assays are essential for monitoring functional immune changes during infection, therapy, and following vaccination. In this study, we investigated whether mycobacterial growth control in thirty patients with TB disease changes over the course of treatment. Comprehensive immune profiling of peripheral blood mononuclear cells (PBMCs), using a 30-color spectral flow cytometry panel, identified dynamic shifts in immune cell subsets related to functional activity. Notably, in addition to memory and effector T cells, a subset of naive B cells changed during treatment. Most sera contained antibodies binding to purified protein derivative (PPD) and Mtb-specific antigens ESAT-6/CFP-10, and enhanced phagocytic activity. A functional mycobacterial growth inhibition assay (MGIA) revealed growth control, which appeared to be heterogeneous but generally sustained throughout longitudinal follow-up. We conclude that T and B cell responses change in response to antibiotic treatment of TB disease, but that mycobacterial growth control capacity is a property of the individual, which is not influenced by disease activity or antibiotic treatment.
In pleural tuberculosis (TB), pleural effusion is typically characterized by a lymphocytic-rich exudate; however, neutrophils and macrophages predominate during the initial phase of infection. These immune cells are known to combat pathogens via phagocytosis, degranulation, and formation of extracellular traps (ETs)-a recently recognized defence mechanism. Although in-vitro and in-vivo studies have demonstrated ETs formation during Mycobacterium tuberculosis infection, their presence in clinical samples of patients with pleural TB has not been previously demonstrated. In this study, we employed multiple methods to demonstrate the presence of ETs in tuberculous pleural effusion (TPE) from patients with confirmed TB (Xpert MTB/RIF-positive/culture-positive/pleural biopsy Ziehl-Neelsen-stainingacid fast bacilli-positive). Immunofluorescence microscopy revealed DNA co-localized with ET markers like myeloperoxidase, neutrophil elastase, and citrullinated histones-confirming ETs in TPE samples, and this was further supported by immunoblotting. Proteomic analysis of TPE samples revealed the presence of key ET-associated proteins, including histones, myeloperoxidase, matrix metalloproteinase-9, and the S100A8/A9 complex. Protein-protein interaction and gene ontology analyses revealed that these proteins are involved in ET-related biological processes, such as neutrophil degranulation and collagen degradation. To the best of our knowledge, this is the first clinical evidence of ETs in TPE, suggesting a potential role in the immunopathogenesis of pleural TB.
Tuberculosis (TB) remains a major global health challenge due in part to limitations in rapid and affordable diagnostics. Current diagnostic methods are time-intensive and often inaccessible in resource-limited settings, emphasizing the urgent need for rapid, low-cost screening approaches. One promising strategy involves the analysis of volatile molecules associated with TB-infection. In this study (n=100) we identify 14 sputum-derived volatiles and utilize them to construct a machine learning model that classifies samples by TB status with a sensitivity of 90% and a specificity of 86% across cross-validation folds. The resulting profile provides a foundation for further biomarker validation studies with an expanded sample size and the development of non-invasive breath diagnostics.
Background Spinal tuberculosis (STB) is an infectious disease caused by Mtb with unclear diagnosis and molecular mechanisms. Autophagy is reported to be associated with the pathology of spinal tuberculosis. The present study intends to elucidate the role of autophagy-related miRNAs and genes in STB. Methods Core miRNAs were identified through WGCNA and differential analysis. A total of 113 machine learning algorithms were used to develop a diagnostic model. Target genes were predicted and overlapped by TargetScan, miRDB, and miRTarBase. The two-sample Mendelian randomization analysis was utilized to explore the association between genes and tuberculosis. Results Nine autophagy-related miRNAs were identified. The GBM model yielded the best performance with the highest AUC (0.816). A signature comprising eight miRNAs, specifically miR-27b-3p and miR-27a-3p, was constructed accordingly. A nomogram was established to facilitate clinical implementation. ZFHX3 gene was indicated to be significantly associated with sequelae tuberculosis. Notably, the ZFHX3/miR-27 axis has never been reported in the realm of tuberculosis. Conclusions The present research established an optimal machine learning model to predict the possibility of STB, which might provide valuable insights into the diagnosis and treatment of STB. ZFHX3/miR-27 may serve as a novel potential molecular pathway in Mtb pathophysiology.
Tubercular uveitis is an extrapulmonary form of TB characterized by ocular inflammation that clinically mimics other inflammatory eye diseases, including non-tubercular uveitis. Currently, no gold standard test is available for the diagnosis of tubercular uveitis, and it is primarily based on clinical presentation. OBJECTIVE:To characterise the transcriptional landscape of vitreous fluid of tubercular uveitis and non-tubercular uveitis patients for biomarker identification and gaining insights into disease pathology. DESIGN:Vitreous fluid samples from uveitis patients were processed for isolation of cells and RNA sequencing to compare the transcriptomic profiles of TB and non-TB uveitis entities. Differentially expressed genes were identified using the criteria of false discovery rate (FDR) < 0.25, fold-change (FC) ≥ 2 or ≤ -2, and p-value <0.05 and the top dysregulated genes were selected for biomarker validation. Additionally, gene set enrichment analysis (GSEA) was performed to explore underlying disease mechanisms. RESULTS:RNA sequencing revealed distinct vitreous fluid gene expression patterns in TB uveitis and non-TB uveitis. Notably, MIR581 and MIR4762, encoding miR-581 and miR-4762, respectively, were among the most upregulated genes. Validation via qRT-PCR confirmed the upregulation of mature miR-4762-5p, supporting its potential as a diagnostic biomarker. Pathway enrichment analysis based on transcriptional profiling revealed significant downregulation of immune-related pathways in tubercular uveitis. CONCLUSION:Unique transcripts are associated with TB uveitis, identifying miR-4762 as a potential diagnostic biomarker. Further, downregulation of transcripts associated with immune-related pathways suggests that Mycobacterium tuberculosis (Mtb) may utilize complex molecular strategies to evade host immune responses and establish infection in the ocular environment.
Linezolid is an essential drug for treating multidrug-resistant and extensively drug-resistant tuberculosis, yet its long-term use is frequently limited by peripheral neuropathy, which in severe cases may be irreversible. To investigate biological factors underlying susceptibility, we analyzed transcriptomic profiles of peripheral blood mononuclear cells from 51 MDR/XDR-TB patients before and after six months of linezolid treatment, stratifying individuals into asymptomatic, mild, and severe neuropathy groups. Patients who later developed severe neuropathy already exhibited distinct transcriptional signatures at baseline, including evidence of immune dysregulation and impaired antioxidant defense, with downregulation of genes involved in immune receptor activity and the pentose phosphate pathway. Following treatment, these patients showed limited transcriptional responses compared with other groups, most notably a marked downregulation of IL10, a central anti-inflammatory cytokine, suggesting maladaptive systemic regulation. Using a machine learning-based feature selection approach, we derived an 11-gene predictive model that achieved strong performance with a cross-validated AUC of 0.93. Model interpretation using SHAP values highlighted HP and HSPA1B as the most influential predictors. Overall, our findings suggest that severe linezolid-induced peripheral neuropathy is predisposed by baseline immune and metabolic alterations and that patients with this complication fail to mount appropriate systemic responses during treatment.
BACKGROUND:Individuals infected by Mycobacterium tuberculosis (Mtb) develop tuberculosis (TB) which is a chronic infectious disease with the main transmission route being the respiratory tract. Currently, 24% of TB patients are still not detected in time, which shows the shortcomings of current diagnostic methodology. METHODS:We developed a novel Whole Slide Imaging (WSI) platform for TB detection, integrating a proprietary Curved Surface Focus Algorithm (CSFA) for high-speed, full-slide digitization under oil immersion, and a two-stage deep learning AI pipeline (YOLOv5 for sensitive candidate detection and ResNet-18 for specific classification) for automated acid-fast bacilli (AFB) identification. We prospectively and retrospectively evaluated its diagnostic performance against conventional smear microscopy, culture, and Xpert MTB/RIF in 1097 patients. RESULTS:The results indicate that in the 1097 study population, WSI-TB showed an overall sensitivity of 42.43% and a specificity of 100.00%. Its sensitivity was higher than that of traditional acid-fast staining smear (18.80%) and culture method (30.36%). Compared with other methodologies, the sensitivity was significantly improved. In the sputum smear microscopy group with 600 visual fields, the positive rate of WSI-TB compared with manual microscopy was 42.43% versus 18.8%; in the sputum culture group, it was 43.46% vs 30.36%; in the Xpert group, it was 62.95% versus 44.26% CONCLUSIONS: The WSI-TB technology significantly improves the sensitivity of tuberculosis sputum smear testing while maintaining 100% specificity, providing a new approach to enhance TB detection rates.
Clofazimine, moxifloxacin and terizidone/cycloserine play an important role in the treatment of drug-resistant tuberculosis (DR-TB). Personalized therapy guided by model-informed precision dosing (MIPD) can be a powerful tool to improve treatment outcomes, minimize adverse effects and combat the emergence of resistance. To set up an MIPD workflow, a population pharmacokinetic model (popPK model) is required. In this study, an external evaluation of popPK models of the three aforementioned drugs was carried out, using pharmacokinetic data from a cohort of patients with DR-TB, in order to identify the model with the best predictive performance. The best performing models (Abdelwahab et al. for clofazimine, Chirehwa et al. for moxifloxacin and Mulubwa and Mugabo for terizidone/cycloserine) were selected to calculate the area under the concentration-time curve (AUC, total exposure). An interoccasion variability (IOV, variability across dosing occasions) of AUC was quantified (13.4%CV (clofazimine), 16.1%CV (moxifloxacin), 14.5%CV (cycloserine)) indicating that using samples from one dosing occasion for AUC calculations may be sufficient to guide potential dose adjustment. Various single sampling schemes to estimate AUC were evaluated, but a unified timepoint for all drugs could not be determined. Known pharmacodynamic targets (AUC0-24h/MIC, or T>MIC) were attained in almost all patients and dosing occasions.
BACKGROUND/OBJECTIVES:Tuberculous pleuritis (TP), a common manifestation of Mycobacterium tuberculosis infection, poses challenges in differentiating microbiologically positive (PEMP-MT) from negative (PEMN-MT) pleural effusions due to the limited sensitivity of traditional diagnostic methods. METHODS:Proteomics analysis using iTRAQ, non-targeted metabolomics, parallel reaction monitoring (PRM), and machine learning were employed to diagnose PEMN-MT or PEMP-MT. A validation cohort of 63 PEMN-MT and 28 PEMP-MT patients underwent ELISA experiments. Receiver operating characteristic (ROC) curves evaluated the predictive value of LDH and LV218 individually and in combination. RESULTS:Differentially expressed proteins (DEPs) and metabolites (DEMs) were identified using bioinformatics tools and pathway enrichment analyses. A machine learning model utilizing six biomarkers (LV218, F13A, RET4, LV321, TBA1C, and LDH) demonstrated excellent diagnostic performance with an AUROC of 0.987 and an AUPR of 0.974, distinguishing PEMP-MT from PEMN-MT. ROC curve analysis showed that both LDH and LV218, alone and in combination, provided strong predictive value for distinguishing the two groups. CONCLUSION:LDH and LV218 are promising biomarkers for differentiating microbiologically positive and negative pleural effusions in tuberculous pleuritis. These biomarkers, particularly when combined, could improve diagnostic accuracy and clinical management.
Tuberculosis (TB) remains the world's deadliest infectious disease, with treatment increasingly complicated by the emergence of multidrug-resistant strains (MDR-TB). This study conducted structure-based drug screening targeting Mycobacterium tuberculosis protein kinase B (MtPknB), a serine/threonine kinase essential for M. tuberculosis survival and proliferation, to identify novel anti-TB drug candidates. From the ChemBridge library, a hierarchical screening pipeline integrating docking and molecular dynamics simulations identified candidate compounds. Among these, a quinoline-pyridine hybrid chemical demonstrated antibacterial activity against Mycobacterium smegmatis (IC50 = 31.8 μM) without toxicity to Escherichia coli or mammalian cells. MM-PBSA and ab initio fragment molecular orbital (FMO) analyses revealed LEU17, VAL25, and MET155 as key stabilizing residues in the MtPknB active site. ProLIF interaction fingerprinting confirmed stable hydrophobic and van der Waals interactions formed by the quinoline-pyridine hybrid chemical. SwissADME and ProTox-3.0 predictions indicated favorable drug-like properties for the quinoline-pyridine hybrid chemical, despite potential toxicity risks. Structure-activity relationship analysis of the quinoline-pyridine hybrid chemical analogs demonstrated that subtle variations in hydrophobic interactions and substituent positioning significantly influence antibacterial potency. These findings position these chemicals as promising lead compounds for MtPknB-targeted anti-TB drug development.
Tuberculosis, primarily caused by Mycobacterium tuberculosis (Mtb), remains a leading global health issue. We investigate the interplay between Mtb infection and various programmed cell death (PCD) in active pulmonary tuberculosis (ATB). Using GSE19491 and GSE107994 datasets, we identified 1306 overlapping differentially expressed genes (DEGs) in peripheral blood from ATB patients and healthy controls. Gene set variation analysis revealed that, except for cuproptosis, the PCD pathways: necroptosis, apoptosis, pyroptosis, and ferroptosis were significantly elevated in ATB patients. Weighted Gene Co-expression Network Analysis further identified 392 PCD-associated hub genes. KEGG and GO analyses highlighted key functional enrichments in immune responses, cellular stress, and PCD pathways. Moreover, we found a positive correlation between PCD types and specific immune cell populations. Additionally, by integrating DEGs of peripheral blood samples and lung granuloma tissues with PCD-associated hub genes, we identified 30 PCD-related genes in ATB patients. RT-qPCR results demonstrated significantly elevated GCLC, RBCK1, ZEB1, and EIF2AK2 levels, alongside lowered PLA2G4C and CAMK2G levels in patients' peripheral blood. These findings underscore the critical role of PCD pathways in modulating the immune response during Mtb infection. Future mechanistic studies are required to definitively establish the causal roles of these pathways in regulating cell death and bacterial control.
In the present study, a series of new pyridine-embedded 1,3,4-oxadiazole derivatives (OXn series) bearing terminal long-chain alkoxy groups like decyloxy, dodecyloxy, tetra decyloxy, and hexadecyloxy groups have been systematically synthesized. Further, the presence of these long-chain alkoxy groups in the OXn series would help to improve the overall molecular lipophilicity and ability to penetrate the lipid-rich mycobacterial cell membrane. Molecular docking has been performed against the mycobacterial InhA enzyme to gain an insight into the possible interactions with the protein, which could pave the way for our endeavor to identify potent antitubercular candidates. Also, these compounds were evaluated for their in vitro antitubercular activities. Among the screened compounds of OXn series, the compound (OX-14) have exhibited potent antitubercular activity against Mycobacterium tuberculosis H37Rv strain with MIC value 32.0 μg/mL and IC50 value of 10.4 μg/mL. We believe that further optimization of this molecule may lead to potent antitubercular agents.
