Bovine tuberculosis is mainly caused by Mycobacterium bovis. Bacillus Calmette-Guérin (BCG) is an attenuated strain of M. bovis which provides variable disease protection. Lesions have been characterized in infected catt...Bovine tuberculosis is mainly caused by Mycobacterium bovis. Bacillus Calmette-Guérin (BCG) is an attenuated strain of M. bovis which provides variable disease protection. Lesions have been characterized in infected cattle, but little comparison has been done with lesions which form in BCG-vaccinates. Here, in situ hybridization examined differences in expression of M. bovis RNA, inducible nitric oxide synthase 2, and vascular endothelial growth factor A in relation to vaccination status and granuloma grade, using two different groups of cattle. Data found no differences between vaccination groups or granuloma grade in average copies of M. bovis mRNA per μm of total granuloma area or per μm of necrotic areas. Within a vaccination group high-grade granulomas had more NOS2 per cell, per μm and a higher percentage of cells expressing NOS2 than low-grade granulomas. Non-vaccinates had a higher percentage of cells producing NOS2 than vaccinates. Differences in NOS2 expression varied by group. Vaccination status and granuloma grade did not affect the average copies of VEGFA per cell or the percent of cells expressing RNA, however VEGFA copies per μm varied between groups. These findings suggest NOS2 and VEGFA are likely not mechanisms of BCG vaccination protection but may impact disease severity.
Tuberculosis (TB) remains a highly lethal infectious disease. The primary preventive measure is Bacille Calmette-Guérin (BCG), a live attenuated vaccine. However, the current intradermal vaccination method with 10-dose v...Tuberculosis (TB) remains a highly lethal infectious disease. The primary preventive measure is Bacille Calmette-Guérin (BCG), a live attenuated vaccine. However, the current intradermal vaccination method with 10-dose vials faces challenges such as inadequate infant injection, inaccurate dispensing, and unstable storage. Researchers have explored microneedle (MN) technology to address these concerns as a intradermal vaccine delivery approach. MN array patches offer painless administration, convenience, improved immunogenicity, and vaccine stability. This study aimed to develop a coated MN system using a micro-dispensing technique at a low temperature (4 °C) and specific excipients for precise dosing and vaccine viability enhancement. Long-term storage stability revealed enhanced storage stability of the BCG-coated MN (BCG-MN) vaccine, maintaining a survival rate of over 60 % for 8 weeks at -20 °C. In vivo vaccination tests using BCG-MN vaccines on guinea pigs exhibited no adverse reactions. Moreover, the BCG-MN vaccine demonstrated superior immune response compared to injections, suggesting that this BCG vaccine-coated MN platform has the potential as a single-dose TB vaccination technology, offering precise dosing control and enhanced immune effectiveness with high storage stability.
The limitations of existing mouse models of lung infection with Mycobacteroides abscessus impede drug discovery and development. In contrast to current animal models that introduce NTM intravenously or by intranasal/intr...The limitations of existing mouse models of lung infection with Mycobacteroides abscessus impede drug discovery and development. In contrast to current animal models that introduce NTM intravenously or by intranasal/intra-tracheal instillation or via bronchoscopy-guided insufflation, we developed a dry powder inhalation (DPI) of M. abscessus ATCC 19977 that generated paucibacillary lung infection and histopathology in immunocompetent mice. Swiss outbred mice receiving ∼1000 (3-log) colony forming units (CFU) of M. abscessus/gram lung tissue via the DPI administered by nose-only inhalation for 90 s showed peak bacterial burden of ∼3.35-log CFU/g in the lungs after 28 days. This was maintained at ∼2-log/g from Day 35 through 56 in the lungs, but not in the spleen. Histopathology indicated increasing severity of inflammation, fibrosis and lung consolidation. Bacteria were rarely recovered from spleen, and histopathological examination indicated partial resolution in the spleen between Days 49-56. The DPI, prepared by freeze-drying log-phase liquid culture with cryoprotectants was formulated to possess aerosol characteristics suitable for alveolar deposition. Aerosol exposure to inoculum mimics natural airborne infection. Non-invasive aerosol infection is convenient, inexpensive, does not require special equipment or extensive training and mitigates stress to animals, but biosafety level 3 containment is recommended to mitigate risk to experimenters.
Multi-drug-resistant Mycobacterium tuberculosis is an escalating global health problem, and a strong pipeline of novel compounds is needed to combat rising antimicrobial resistance. Ecumicin is a novel analogue of the na...Multi-drug-resistant Mycobacterium tuberculosis is an escalating global health problem, and a strong pipeline of novel compounds is needed to combat rising antimicrobial resistance. Ecumicin is a novel analogue of the natural antimycobacterial cyclic peptide ecumicin, with selective activity against Mycobacterium species. The activity of ecumicin∗ was compared to that of frontline tuberculosis therapies under in vitro conditions representative of niches where M. tuberculosis resides in the human lung. M. tuberculosis expressing luciferase was cultured in defined 7H9-based media containing glucose, butyrate, valerate, acidified glucose, low or high cholesterol concentrations, or intracellularly in human THP-1 and mouse RAW264.7 macrophages. Ecumicin∗ effectively killed M. tuberculosis under all assay conditions. The IC of ecumicin∗ was increased in acidified 7H9 media, and both IC and AUC values were increased in valerate, cholesterol, high cholesterol culture media. In time-kill assays, anti-M. tuberculosis activity of ecumicin∗ was sustained for 28 days. By comparison, IC and IC of isoniazid were decreased in butyrate and cholesterols medias, and mycobacterial regrowth occurred in glucose and cholesterol culture medias within 14 days at high isoniazid concentrations. Ecumicin∗ inhibited M. tuberculosis growth in THP-1 macrophages, and at higher IC in mouse RAW264.7 macrophages. Drug testing under disease-relevant conditions is important prior to in vivo examination, and ecumicin∗ has proven effective in multiple in vitro conditions typical of the lung environment of tuberculosis patients.
PURPOSE: Tuberculosis (TB) remains a significant public health concern globally. Bacille Calmette-Guérin (BCG) vaccination is widely used, but scar formation post-vaccination is not universal, which raises concerns about...PURPOSE: Tuberculosis (TB) remains a significant public health concern globally. Bacille Calmette-Guérin (BCG) vaccination is widely used, but scar formation post-vaccination is not universal, which raises concerns about its efficacy. The Mantoux test is used to assess the immune response following BCG vaccination. This study aims to evaluate the prevalence of BCG scar formation among vaccinated children and its correlation with Mantoux test reactions. METHODS: This quantitative, cross-sectional descriptive study was conducted among children aged 3 months to 9 years at the vaccination office in Omdawanban, Sudan, from September to October 2021. Data were collected using structured surveys and the Mantoux skin test. RESULTS: Out of 350 vaccinated children, 285 (81.4 %) exhibited a visible BCG scar, while 65 (18.6 %) did not. Mantoux test positivity was observed in 132 children (37.7 %). A significant association was found between the presence of a BCG scar and a positive Mantoux test result (p < 0.05), with 39.3 % of children with a visible scar showing positive Mantoux results compared to 30.8 % of children without a scar. The likelihood of a positive Mantoux test was 3.2 times higher in children with a visible BCG scar (OR = 3.2, 95 % CI [1.8-5.8]). Mantoux positivity also varied by age, with the highest rate (41.2 %) observed among children aged 5-9 years (p = 0.03). CONCLUSIONS: There is a significant association between BCG scar formation and Mantoux test positivity. Improved training for healthcare workers and better education for mothers about vaccination are recommended.
BACKGROUND: Interferon-γ release assays (IGRAs) for tuberculosis infection (TBI) cannot distinguish different stages of the TBI spectrum (including spontaneously cleared infection). We investigated patterns of Mtb-specif...BACKGROUND: Interferon-γ release assays (IGRAs) for tuberculosis infection (TBI) cannot distinguish different stages of the TBI spectrum (including spontaneously cleared infection). We investigated patterns of Mtb-specific blood mediators in people with and without TBI during tuberculosis preventive therapy (TPT). METHODS: Individuals with likelihood of recent Mtb exposure, aged 15-25 years, with valid IGRA results, in whom tuberculosis (TB) had been excluded, were included. Persons with TBI were sampled prior to TPT (IGRA + pre-treatment, n = 15) or after completion of TPT (IGRA + post-treatment, n = 15). Five persons without TBI were included as controls (IGRA-). Levels of 40 mediators related to TB immune control in blood incubated with Mtb antigens in the QuantiFERON-TB Plus® kit were assessed with electrochemiluminescence assay and compared between participant categories. RESULTS: The concentration of 10 mediators (GM-CSF, interferon-γ, IL-2, I-TAC, IL-12, IP-10, I-309, MCP-2, MIG, and VEGF) significantly differed between IGRA + pre-treatment and IGRA-. A non-significant trend in levels of these markers was observed between IGRA + pre-treatment, IGRA + post-treatment and IGRA-. Based on these mediators two clusters were identified: A (n = 16), including 5 IGRA-, 4 IGRA + pre-treatment, 7 IGRA + post-treatment and B (n = 19), including 11 IGRA + pre-treatment and 8 IGRA + post-treatment. CONCLUSION: Plasma levels of several Mtb-triggered mediators differed with regard to TBI status among persons recently exposed to TB, suggesting the potential for alternative markers to assess TBI status. Longitudinal analysis of these mediators during TPT is warranted to explore whether these markers can be used to assess likelihood of persistence of viable bacilli in Mtb-exposed individuals. CLINICALTRIALS: govID:NCT05621343.
BACKGROUND: Immune imbalance is crucial in tuberculosis pathogenesis and may be modulated by mesenchymal stem cells (MSCs). However, how MSCs regulate the host's response to Mycobacterium tuberculosis (Mtb) is unclear. M...BACKGROUND: Immune imbalance is crucial in tuberculosis pathogenesis and may be modulated by mesenchymal stem cells (MSCs). However, how MSCs regulate the host's response to Mycobacterium tuberculosis (Mtb) is unclear. METHODS: Human umbilical cord-derived MSCs were co-cultured with Mtb-infected THP-1 macrophages. The intracellular release of ROS in macrophages was measured by DCFH-DA. Cytokine expression was measured by RT-qPCR, apoptosis by Annexin V/PI assay, and pyroptosis markers by Western blotting. Differentially expressed genes (DEGs) in Mtb-infected THP-1 co-cultured with or without MSCs were identified by RNA-seq and potential signaling pathways were analyzed through bioinformatics. RESULTS: The fibroblastic morphology of MSCs exhibited 95 % positivity for CD73, CD90, and CD105, while the positivity rate for negative marker HLA-DR was less than 2 %. In Mtb-infected THP-1 macrophages, co-culturing with MSCs increased ROS release, cytokines expression (IL-1β, IL-6, TNF-α), apoptosis, and pyroptosis markers (NLRP3, Caspase-1, and GSDMD). Comparative transcriptome analysis identified 347 up-regulated and 291 down-regulated DEGs, primarily associated with receptor-ligand interactions and enriched in cytokine signaling pathways including JAK-STAT, TNF, ferroptosis, and autophagy. CONCLUSION: MSCs could enhance the macrophages' immune response to Mtb by activating immune receptors and inflammatory signaling pathways.
Liu J, Phelps GA, Dunn CM
… +10 more, Murphy PA, Wilt LA, Loudon V, Lee RB, Fernando D, Yang L, Tran KN, Troyer BT, Obregon-Henao A, Lee RE
Tuberculosis (Edinb)
· 2025 Jan · PMID 39708619
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Tetracycline analogs from the minocycline family have recently shown promise for the treatment of non-tuberculous mycobacterial infections. However, current tetracycline and minocycline therapeutics can be limited by tol...Tetracycline analogs from the minocycline family have recently shown promise for the treatment of non-tuberculous mycobacterial infections. However, current tetracycline and minocycline therapeutics can be limited by tolerability, stability, or inactivation by TetX. In this study, a series of novel 9-heteroaryl substituted minocycline analogs were designed and synthesized, which resulted in analogs with good in vitro activity against Mycobacterium tuberculosis and Mycobacterium abscessus, stability in water for more than 7 days, avoidance of TetX inactivation in M. abscessus, and a lack of cytotoxicity in HepG2 mammalian cells. In vivo efficacy was confirmed for the tetracycline analogs in an acute model of GM-CSF KO mice infected with M. abscessus, displaying superior efficacy to standard-of-care antibiotic clarithromycin. Molecular modeling and potentiation assays demonstrate avoidance of MabTetX, and the structure-activity relationships of the series are discussed herein for M. tuberculosis and M. abscessus.
We surveyed 15 persons with a medical qualification, 133 graduate students doing biomedical research and 56 students or working people with a college education in any discipline. Questions were designed to gauge awarenes...We surveyed 15 persons with a medical qualification, 133 graduate students doing biomedical research and 56 students or working people with a college education in any discipline. Questions were designed to gauge awareness about inhaled therapies for tuberculosis (TB), non-tubercular mycobacterial lung disease (NTM-LD) and idiopathic pulmonary fibrosis (IPF). Respondents from six cities in North India, aged between 21 and 57 years answered 20 questions. All physicians, 99.25 % of graduate students and 85.71 % of the rest were aware and positive about inhalations for asthma, but these proportions fell to 69.92 and 66.07 in respect of other diseases. All respondents in the first two categories agreed that it was easy to train patients in the use of inhalation devices, while the third group was unanimous that there would be no aversion to using inhalation devices. A question asking whether the respondent would prescribe or opt for inhaled therapies for own use elicited an affirmative answer only from 40.00 % of physicians, 43.61 % of researchers and 23.21 % of college-educated persons (overall: 37.56 %). We concluded that inhaled therapies for diseases other than asthma are not well known and find limited acceptance among the populations sampled.
Extracellular vesicles (EVs) have recently emerged as a source of microbe-specific biomarkers for disease diagnosis. In the present study, we evaluated the utility of pleural fluid-derived extracellular vesicles (pEVs) a...Extracellular vesicles (EVs) have recently emerged as a source of microbe-specific biomarkers for disease diagnosis. In the present study, we evaluated the utility of pleural fluid-derived extracellular vesicles (pEVs) as a source of Mycobacterium tuberculosis (M. tb.) antigens for pleural TB (pTB) diagnosis. EVs were isolated from pleural fluid (PF) samples and were characterized by scanning electron microscopy, and immunoblotting by targeting CD63 and LAMP2 markers. Antigen-detection ELISAs were developed for 2 M.tb.-specific antigens, MPT51 and MPT64 in pEVs (pEV-ELISA) and direct PF samples (PF-ELISA), and were evaluated on n = 86 samples in a blinded manner. Cut-off values were calculated by ROC-curve analysis to achieve 90 % (95%CI:73.47-97.89) and 86.67 % (95%CI:69.28-96.24) specificity for MPT51 and MPT64 pEV-ELISA respectively. The sensitivity of pEV-ELISA was 71.43 % (95%CI; 29.04-96.33) for MPT51 antigen and 57.14 % (95%CI; 18.41-90.1) for MPT64 antigen in the 'Definite' pTB group, while in the 'Definite and Probable' pTB group, the sensitivity was 62.86 % (95%CI:44.92-78.53) for MPT51 and 65.71 % (95%CI:47.79-80.87) for MPT64. The performance of PF-ELISA was sub-optimal, with 28.57 % (95%CI:3.67-70.96) and 14.29 % (95%CI:0.36-57.87) sensitivity for MPT51 and MPT64 in 'Definite' pTB group respectively. We conclude that M. tb.-antigens are concentrated in the EV-fraction of PF samples and EVs can be utilized for antigen-detection assays for pTB diagnosis.
Tuberculosis (TB) is a global health problem with diverse clinical manifestations. Different cells of the immune response participate in containing the infection, mainly through the development of granulomas. Mast cells...Tuberculosis (TB) is a global health problem with diverse clinical manifestations. Different cells of the immune response participate in containing the infection, mainly through the development of granulomas. Mast cells (MCs) are hematopoietic cells that participate in the immune response to different pathogens, and in vitro evidence indicates that they can be activated by Mycobacterium tuberculosis (Mtb). The aim of this study was to evaluate the role of MCs in a murine TB model. We observed that Kit mast cell-deficient mice showed increased bacterial load in the lungs and the spleen compared to wild-type C57BL/6 mice. Furthermore, MC-deficient mice showed fewer pulmonary granulomas but an early higher inflammatory infiltrate. Interestingly, serum cytokine levels were altered in MC-deficient mice, which showed increased levels of IL-4, IL-5, and IL-22 during the early phase of the infection but increased levels of IFN-γ, IL-9, IL-10, and IL-21 during the late phase of the infection. These results show that mast cells play an important role during Mtb infection by modulating the immune response to the bacteria.
Given the increasing prevalence of drug-resistant tuberculosis (TB), there is an urgent demand in developing novel anti-TB medications with highly effective, safe, and utilize innovative mechanisms of action. Blocking th...Given the increasing prevalence of drug-resistant tuberculosis (TB), there is an urgent demand in developing novel anti-TB medications with highly effective, safe, and utilize innovative mechanisms of action. Blocking the mycolic acid synthesis pathway is well-established to be a significant strategy in developing anti-TB drugs, and Pks13 was identified as a crucial enzyme in this process. Importantly, the modes of action of recognized Pks13 inhibitors differ from traditional anti-TB medications, highlighting Pks13 as a potential and promising target in drug development within TB treatment. In this study, we discovered a compound named BMVC-8C3O that effectively inhibited the activity of Pks13 with a 6.94 μM IC value. The binding between BMVC-8C3O and Pks13 was validated through surface plasmon resonance (SPR) assay as well as molecular docking analysis. Moreover, the SPR assay showed that the mutation of Asn1640 and Ser1533 resulted in decreased affinity of BMVC-8C3O to Pks13. Additionally, BMVC-8C3O not only exhibited activity against Mycobacterium tuberculosis (MTB), but also displayed potential intracellular anti-TB activity in macrophages. In summary, our findings indicate that BMVC-8C3O holds great potential as a lead compound against TB.
BACKGROUND: Pulmonary tuberculosis (PTB) is the main cause of infection-related mortality and the most common infectious disease that develops resistance to antibiotics. Gut microbiota and their associated metabolites ar...BACKGROUND: Pulmonary tuberculosis (PTB) is the main cause of infection-related mortality and the most common infectious disease that develops resistance to antibiotics. Gut microbiota and their associated metabolites are assumed to induce and influence the development of PTB. However, the alterations of gut microbiota and metabolites in TB patients is currently unclear. METHODS: Fecal samples were collected from 13 PTB patients, 13 LTBI patients, and 13 healthy controls (HC). 16S rRNA sequencing and metabolomics were used to analyze the changes in the intestinal microbiota and the composition of fecal metabolites in groups. RESULTS: Our findings indicated that the α-diversity of the gut microbiota in patients with PTB and LTBI decreases compared to HC, and at the phylum level, the relative abundance of Firmicutes decreases and the relative abundance of Bacteroides increases. And six genera were notably enriched in PTB patients and four in LTBI patients. Metabolomic analysis showed alterations in metabolite levels, such as short-chain fatty acids and amino acids. CONCLUSIONS: we comprehensively explored the changes in the gut microbes and fecal metabolites in patients with PTB and LTBI from the perspective of the gut microbiota, which may provide potential diagnostic biomarkers and therapeutic targets for TB diagnosis and treatment.
Several mycobacterial species are known to cause human diseases, such as tuberculosis and leprosy. In addition to these pathogenic species, there are also saprophytic representatives, which occasionally cause opportunist...Several mycobacterial species are known to cause human diseases, such as tuberculosis and leprosy. In addition to these pathogenic species, there are also saprophytic representatives, which occasionally cause opportunistic infections. It is well established that numerous mycobacteria produce biofilms containing cellulose, and their genomes frequently harbor genes involved in cellulose degradation, such as celA1. Notably, the BCG Moreau vaccine strain carries a specific deletion of two-base pairs, resulting in a predicted protein with fewer than 100 amino acids in the catalytic portion at the C-terminal end. We investigated the functional consequences of this polymorphism and observed that recombinant enzyme from the Moreau strain lack catalytic activity. Furthermore, compared to the Pasteur strain, Moreau is unable to utilize carboxymethylcellulose (CMC) as the sole carbon source. These findings suggest an absence of cellulolytic activity in this strain, which may influence the bacterium virulence.
The sensitivity of Xpert MTB/RIF (Xpert) pooled testing is limited for diagnosing patients with paucibacillary tuberculosis (TB). We assessed whether pooled testing with Xpert MTB/RIF Ultra (Ultra) can be a sensitive and...The sensitivity of Xpert MTB/RIF (Xpert) pooled testing is limited for diagnosing patients with paucibacillary tuberculosis (TB). We assessed whether pooled testing with Xpert MTB/RIF Ultra (Ultra) can be a sensitive and effective approach for mass TB screening. Conserved, frozen sputum samples, previously confirmed as positive or negative for Mycobacterium tuberculosis by individual Xpert assays, were mixed in pools of 4, 8, and 16 and then tested using Ultra. Each pool contained a single positive sample with varying mycobacterial loads. We then simulated TB screening at prevalence ranges of 0.2-1.0 % and calculated the cartridges required per case detected at different pool sizes. The overall sensitivity of Ultra pooled testing was high (88.9 %, 75.9-96.3). Sensitivity was greater in pools in which the positive sample had a high mycobacterial load compared to those with scant bacilli. As prevalence increased, the optimal pool size and benefits of pooled testing declined, but a pool size of 8 resulted in at least 80 % cartridge savings with the highest simulated prevalence. Sputum pooling using Ultra could be a sensitive and effective strategy for TB screening. However, broad TB screening in communities with limited resources will require new, lower-cost, high-throughput screening tools, perhaps based on non-sputum specimens.
A vaccine for bovine tuberculosis is urgently needed. The BCG vaccine (the Bacille Calmette-Guérin), currently the only licensed vaccine for tuberculosis in humans, offers variable protection in cattle. However, BCG is a...A vaccine for bovine tuberculosis is urgently needed. The BCG vaccine (the Bacille Calmette-Guérin), currently the only licensed vaccine for tuberculosis in humans, offers variable protection in cattle. However, BCG is a highly safe vaccine, and any alternative vaccine must not only offer greater protection than BCG but also match and improve its safety profile. Mice are the most widely used animal models in tuberculosis research, particularly for pre-clinical vaccine evaluation. In these animal models, the key indicator of infection or vaccine efficacy is the mycobacteria load in the lungs. In this study, we evaluated the long-term protection conferred by vaccinating BALB/c mice with a Mycobacterium bovis triple mutant lacking the virulence genes phoP, esxA, and esxB. Our findings showed that the triple mutant protected the lungs of mice against M. bovis challenge for up to one-year post-vaccination. However, the bacterial load in the spleens predominantly comprised the vaccine strain, and the lungs also contained some of these bacteria. These results suggest that the vaccine strain persisted in the mouse organs for at least one year, which raised concerns about its potential safety for animal vaccination.
Mycobacterium tuberculosis (MTB/Mtb) is the causative agent of tuberculosis (TB), a highly infectious serious airborne illness. TB usually affects the lungs, in 25 % of patients (children or immune impaired adults), myco...Mycobacterium tuberculosis (MTB/Mtb) is the causative agent of tuberculosis (TB), a highly infectious serious airborne illness. TB usually affects the lungs, in 25 % of patients (children or immune impaired adults), mycobacteria can enter the blood stream and infect other bodily areas such the meninges, pleura, lymphatic system, genitourinary system, bones, and joints. Currently, the most challenging aspect of treating this illness is the ineffectiveness of the most potent first-line anti-TB medications, isoniazid, rifampin, pyrazinamide, and ethambutol, which can result in multidrug-resistant TB (MDR-TB), extensively drug-resistant TB (XDR-TB), and in rare instances, completely drug-resistant TB (TDR-TB). As a result, finding new pharmaceutical compounds to treat these diseases is a significant challenge for the scientific community. A number of bio-active molecules have been investigated in this quest, including quinoline, which is considered a promising candidate for the development of TB drugs. It is known that quinoline are low in toxicity and have a wide range of pharmacological properties. Researchers have investigated quinoline scaffolds as anti-TB drugs based on their biological spectrum. The objective of this review is to examine the recent development of quinoline and its structural characteristics crucial to its antitubercular (anti-TB) activity. A molecular analog of the TB treatment can be designed and identified with this information. As a result, future generation quinoline-based anti-TB agents with greater potency and safety can also be explored.
Bedaquiline (BDQ) has shown efficacy in shortening treatment duration and enhancing treatment success rates for multidrug-resistant tuberculosis (MDR-TB), thereby prompting widespread adoption. However, resistance to BDQ...Bedaquiline (BDQ) has shown efficacy in shortening treatment duration and enhancing treatment success rates for multidrug-resistant tuberculosis (MDR-TB), thereby prompting widespread adoption. However, resistance to BDQ has emerged. This study aimed to identify genetic characteristics associated with decreased susceptibility to BDQ, using a public database to aid in the detection of resistant strains. Seventy-one BDQ-resistant and 929 BDQ-susceptible isolates from the open-source CRyPTIC database were selected for analysis. Variant calling was conducted via the clockwork pipeline. Univariate logistic regression was performed for each gene mutation, followed by LASSO regression for further variant selection. Ultimately, a multiple linear regression model was developed using log-transformed Minimum Inhibitory Concentration values as the dependent variable, with variant selection refined through stepwise regression based on the Akaike Information Criterion. Ten gene mutations were significantly associated with reduced BDQ susceptibility, including two key gene mutations: Rv0678_141_ins_1 and Rv1979c_D249E, with effect estimates of 1.76 (95 % CI: 0.67-2.84) and 1.69 (95 % CI: 0.22-3.17), respectively. Other implicated genes included Rv2699c_-84_del_1, hsaB_I179T, mmpL9_T241A, pncA_C14R, Rv0373c_G621S, Rv0893c_L27F, Rv1770_A4D, and Rv3428c_S327C. This study identified ten gene mutations linked to decreased susceptibility to BDQ, providing a reference for developing a comprehensive catalog of BDQ-resistant genes.
Host-directed therapies (HDT) via modulation of specific host responses like inflammation can limit mycobacterial infection. HDTs could be included in current TB therapy as an adjunct to increase bacterial clearance and...Host-directed therapies (HDT) via modulation of specific host responses like inflammation can limit mycobacterial infection. HDTs could be included in current TB therapy as an adjunct to increase bacterial clearance and limit tissue damage to control spread. Individually, Mycobacterium indicus pranii (MIP) and human beta defensin-2 (hBD-2) are promising therapies for tuberculosis (TB). They can directly target the TB bacilli and enhance cell-mediated immune responses, which is limiting with conventional drugs. Therefore, our study investigated the combined application of MIP and hBD-2 to evaluate their efficacy in clearing infections caused by Mycobacterium smegmatis (M.smeg) and Mycobacterium tuberculosis (M.tb) (both avirulent; H37Ra and virulent strain; H37Rv) in THP-1 cells and human monocyte-derived macrophages (MDMs). A strong pro-inflammatory response was observed against the combination of MIP and hBD-2 which also correlated with a significant reduction in the bacterial load. This combination further showed protection against M.tb by enhancing pyroptosis in the infected cells. The study suggests the combined use of these potent immunomodulators, which could be employed as an effective mode of therapy as adjuvants against mycobacterial infections after validation in a suitable animal model.