MDR Tuberculosis Treatment

Performance of a molecular beacon-based qPCR method for detection of fluoroquinolone resistance in Mycobacterium tuberculosis: A study confirmed by sequencing

Multidrug-resistant tuberculosis (MDR-TB) poses a serious threat to the control and treatment of tuberculosis (TB). Rapid diagnosis of resistant strains via utilization of molecular techniques is of critical importance on the proper management of the patients. The objective of this study was to develop a quantitative polymerase chain reaction (qPCR) method for the detection of mutation-based fluoroquinolone (FQ) resistance in Mycobacterium tuberculosis isolates. Primers and a molecular-beacon probe were designed to target quinolone-resistance-determining-region (QRDR) of the gyrA gene of M. tuberculosis. Amplification conditions and concentrations of primers/probe were optimized, and the effectiveness of the optimized qPCR method was tested on 50 MDR M. tuberculosis strains. To confirm the qPCR results, all strains were also screened for mutations in the gyrA gene using Sanger sequencing. The optimized qPCR method had analytical sensitivity of 96.5 cfu/ml. The method detected FQ resistance in 7 (14 %) of the 50 MDR-strains via either no or significantly decreased fluorescence signal due to mutations associated with FQ resistance. The sequencing of these seven strains detected three resistance-associated mutations (A90V, D94A and D94G). Of the 43 FQ-susceptible strains, 10 strains with wild-type gene sequences yielded strong fluorescent signals above 450 RFU, while the remaining 33 strains harboring a non-resistance-associated mutation (S95T) showed decreased fluorescence signals <350 RFU. The sensitivity and specificity of the qPCR method for detection of the mutations related to resistance was ≥99.9 % and 98 %, respectively. Consequently, the utility of the optimized qPCR method for the identification of mutation-based FQ resistance is promising.

Innovative Strategies for Combating Multidrug-Resistant Tuberculosis: Advances in Drug Delivery Systems and Treatment

Multidrug-resistant tuberculosis (MDR-TB) is a significant public health challenge globally, exacerbated by the limited efficacy of existing therapeutic approaches, prolonged treatment duration, and severe side effects. As drug resistance continues to emerge, innovative drug delivery systems and treatment strategies are critical to combating this crisis. This review highlights the molecular mechanisms underlying resistance to drugs in Mycobacterium tuberculosis, such as genetic mutation, efflux pump activity, and biofilm formation, contributing to the persistence and difficulty in eradicating MDR-TB. Current treatment options, including second-line drugs, offer limited effectiveness, prompting the need for innovation of advanced therapies and drug delivery systems. The progression in drug discovery has resulted in the approval of innovative therapeutics, including bedaquiline and delamanid, amongst other promising candidates under investigation. However, overcoming the limitations of traditional drug delivery remains a significant challenge. Nanotechnology has emerged as a promising solution, with nanoparticle-based drug delivery systems offering improved bioavailability and targeted and controlled release delivery, particularly for pulmonary targeting and intracellular delivery to macrophages. Furthermore, the development of inhalable formulations and the potential of nanomedicines to bypass drug resistance mechanisms presents a novel approach to enhancing drug efficacy. Moreover, adjunctive therapies, including immune modulation and host-directed therapies, are being explored to improve treatment outcomes. Immunotherapies, such as cytokine modulation and novel TB vaccines, offer complementary strategies to the use of antibiotics in combating MDR-TB. Personalized medicine approaches, leveraging genomic profiling of both the pathogen and the host, offer promise in optimizing treatment regimens and minimizing drug resistance. This review underscores the importance of multidisciplinary approaches, combining drug discovery, advanced delivery system development, and immune modulation to address the complexities of treating MDR-TB. Continued innovation, global collaboration, and improved diagnostics are essential to developing practical, accessible, and affordable treatments for MDR-TB.

Association Between Diabetes Mellitus-Tuberculosis and the Generation of Drug Resistance

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains one of the leading infectious causes of death globally, with drug resistance presenting a significant challenge to control efforts. The interplay between type 2 diabetes mellitus (T2DM) and TB introduces additional complexity, as T2DM triples the risk of active TB and exacerbates drug resistance development. This review explores how T2DM-induced metabolic and immune dysregulation fosters the survival of Mtb, promoting persistence and the emergence of multidrug-resistant strains. Mechanisms such as efflux pump activation and the subtherapeutic levels of isoniazid and rifampicin in T2DM patients are highlighted as key contributors to resistance. We discuss the dual syndemics of T2DM-TB, emphasizing the role of glycemic control and innovative therapeutic strategies, including efflux pump inhibitors and host-directed therapies like metformin. This review underscores the need for integrated diagnostic, treatment, and management approaches to address the global impact of T2DM-TB comorbidity and drug resistance.

Which fluoroquinolone is safer when combined with bedaquiline for tuberculosis treatment: evidence from FDA Adverse Event Reporting System database from 2013 to 2024

OBJECTIVE

To investigate which fluoroquinolone is safer when combined with bedaquiline for tuberculosis treatment by using the FDA Adverse Event Reporting System (FAERS) database.

METHODS

We selected data from the first quarter (Q1) of 2013 to the second quarter (Q4) of 2024 from the FDA FAERS database for disproportionality analysis. Signal detection was conducted using the Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and Empirical Bayesian Geometric Mean (EBGM).

RESULTS

This study analyzed 12, 303, 879 reports from the FAERS database, including 722 reports related to the combination of bedaquiline and levofloxacin (with 2,723 adverse events) and 573 reports related to the combination of bedaquiline and moxifloxacin (with 2,233 adverse events). For the bedaquiline-levofloxacin regimen, these reports were categorized into 100 preferred terms (PTs) and 24 System Organ Classification (SOCs). The three most common SOCs were hepatobiliary disorders (n = 128, ROR 5.79, PRR 5.56, IC 2.48, EBGM 5.56), blood and lymphatic system disorders (n = 217, ROR 5.04, PRR 4.72, IC 2.24, EBGM 4.71), and metabolism and nutrition disorders (n = 185, ROR 3.44, PRR 3.27, IC 1.71, EBGM 3.27). In terms of PTs, the three strongest signals were portal fibrosis (ROR 330.64), hepatitis C RNA increased (ROR 301.24), and toxic optic neuropathy (ROR 238.11). Reports of prolonged QT interval on ECG (125 cases) and anemia (130 cases) were significantly more frequent than other PTs. For the bedaquiline-moxifloxacin regimen, these reports were categorized into 85 preferred terms (PTs) and 24 System Organ Classification (SOCs). The three most common SOCs were hepatobiliary disorders (n = 141, ROR 7.9, PRR 7.47, IC 2.9, EBGM 7.46), ear and labyrinth disorders (n = 40, ROR 4.03, PRR 3.97, IC 1.99, EBGM 3.97), and cardiac disorders (n = 141, ROR 3.08, PRR 2.95, IC 1.56, EBGM 2.95). The three strongest PT signals were chronic pyelonephritis (ROR 563.29), bronchopleural fistula (ROR 314.86), and toxic neuropathy (ROR 187.11). Prolonged QT interval on ECG (152 cases) remained the most frequently reported PT. In both treatment regimens, individuals under 45 years of age experienced a higher frequency and variety of AEs, indicating the need for enhanced monitoring. For those over 45, particular attention should be given to ECG changes, especially in men. Finally, some PTs with extremely high signal strength, such as chronic pyelonephritis (ROR 563.29), hepatitis C RNA increased (ROR 301.24), and bronchopleural fistula (ROR 301.24), may represent rare adverse events associated with the combination of bedaquiline-fluoroquinolone.

CONCLUSION

Our study suggests that the safety profile of bedaquiline combined with moxifloxacin does not appear superior to that of bedaquiline combined with levofloxacin in terms of cardiac, hepatic, and neurological effects. Therefore, in the BPaLM regimen, considering the substitution of moxifloxacin with levofloxacin may be worthwhile if their efficacy is proven to be similar. Increased monitoring may be required for individuals under 45 years of age and male MDR-TB patients.

Sodium, Potassium-Adenosine Triphosphatase as a Potential Target of the Anti-Tuberculosis Agents, Clofazimine and Bedaquiline

Multidrug-resistant tuberculosis (MDR-TB) patients are treated with a standardised, short World Health Organization (WHO) regimen which includes clofazimine (CFZ) and bedaquiline (BDQ) antibiotics. These two antibiotics lead to the development of QT prolongation in patients, inhibiting potassium (K+) uptake by targeting the voltage-gated K+ (Kv)11.1 (hERG) channel of the cardiomyocytes (CMs). However, the involvement of these antibiotics to regulate other K+ transporters of the CMs, as potential mechanisms of QT prolongation, has not been explored. This study determined the effects of CFZ and BDQ on sodium, potassium-adenosine triphosphatase (Na+,K+-ATPase) activity of CMs using rat cardiomyocytes (RCMs). These cells were treated with varying concentrations of CFZ and BDQ individually and in combination (1.25-5 mg/L). Thereafter, Na+,K+-ATPase activity was determined, followed by intracellular adenosine triphosphate (ATP) quantification and cellular viability determination. Furthermore, molecular docking of antibiotics with Na+,K+-ATPase was determined. Both antibiotics demonstrated dose-response inhibition of Na+,K+-ATPase activity of the RCMs. The greatest inhibition was demonstrated by combinations of CFZ and BDQ, followed by BDQ alone and, lastly, CFZ. Neither antibiotic, either individually or in combination, demonstrated cytotoxicity. Molecular docking revealed an interaction of both antibiotics with Na+,K+-ATPase, with BDQ showing higher protein-binding affinity than CFZ. The inhibitory effects of CFZ and BDQ, individually and in combination, on the activity of Na+,K+-ATPase pump of the RCMs highlight the existence of additional mechanisms of QT prolongation by these antibiotics.

A non-randomized pragmatic historically controlled trial evaluating the effectiveness and safety of a bedaquiline or a linezolid-based short regimen for rifampicin-resistant tuberculosis

BACKGROUND

Short all-oral regimens for Rifampicin-resistant tuberculosis (ShORRT) have been a turning point in the treatment of drug-resistant tuberculosis. Despite this, access to drugs, stockouts, or adverse effects may limit the use of the recommended regimens.

METHODS

Pragmatic non-randomized trial evaluating the efficacy and safety of a ShORRT strategy for the treatment of rifampicin-resistant Tuberculosis (RR-TB) at the Hospital Nossa Senhora da Paz (Angola). The strategy assigned participants to receive a bedaquiline (BDQ) or a linezolid-based (LZF) regimen supplemented with levofloxacin, clofazimine, and cycloserine for up to 9 months.

RESULTS

One hundred and twenty-one participants with pulmonary RR-TB were treated with the ShORRT strategy; 69 received the bedaquiline- and 52 the linezolid-based regimen. Overall, 98 (81%) participants had successful treatment outcomes, which was significantly higher compared to a 20-month historical injectable-based regimen (successful outcome rate including cure and treatment completed: 53.7%) (p < 0.001). No significant differences between treatment success rates (85.5% vs. 75.0%), treatment failure (0.0% vs. 1.9%), death (5.8% vs. 13.5%), or lost to follow-up (LTFU) (8.7% vs. 9.6%) were seen between the BDQ and the LZF-based regimen. Globally, 72 adverse events (AE) occurred in 36 (29.7%) participants. Eighteen (14.9%) of these were grade ≥3 and were more frequently observed in those receiving the LZD-based regimen (p = 0.02).

CONCLUSION

The ShORRT strategy with a nine-month BDQ- or LZD-based regimen supports the efficacy of shorter all-oral regimens for the treatment of RR-TB and presents real-world data from schemes without bedaquiline, nitroimidazole, or injectables.

[Update on the treatment of tuberculosis]

Tuberculosis (TB) affects more than 10 million people each year. We have contested this burden with a paradoxically slow development of treatments, as compared to other infectious diseases. This review aims to update health care professionals on the last developments for the management of TB. The combination of drugs established more than 40years ago is still adequate to cure most people affected by TB. However, with the generalisation of regimens based on rifampicin and isoniazid for (only) 6months, resistance emerged. Resistant cases needed long treatments based on injectable drugs. Now, after an exciting decade of research, we can treat resistant TB with oral regimens based on bedaquiline, nitroimidazoles, and linezolid for (only) 6months, and we may soon break the 6-month barrier for treatment duration. However, these improvements are not enough to end TB without an engagement of people affected and their communities to achieve adherence to treatment, transmission control, and improve socioeconomic determinants of health.

The Biological Characteristics of Mycobacterium Phage Henu3 and the Fitness Cost Associated with Its Resistant Strains

Tuberculosis (TB), caused by Mycobacterium tuberculosis, is an infectious disease that seriously affects human life and health. Despite centuries of efforts to control it, in recent years, the emergence of multidrug-resistant bacterial pathogens of M. tuberculosis due to various factors has exacerbated the disease, posing a serious threat to global health. Therefore, a new method to control M. tuberculosis is urgently needed. Phages, viruses that specifically infect bacteria, have emerged as potential biocontrol agents for bacterial pathogens due to their host specificity. In this study, a mycobacterium phage, Henu3, was isolated from soil around a hospital. The particle morphology, biological characteristics, genomics and phylogeny of Henu3 were characterized. Additionally, to explore the balance between phage resistance and stress response, phage Henu3-resistant strains 0G10 and 2E1 were screened by sequence passage and bidirectional validation methods, which significantly improved the sensitivity of phage to antibiotics (cefotaxime and kanamycin). By whole-genome re-sequencing of strains 0G10 and 2E1, 12 genes involved in cell-wall synthesis, transporter-encoded genes, two-component regulatory proteins and transcriptional regulatory factor-encoded genes were found to have mutations. These results suggest that phage Henu3 has the potential to control M. tuberculosis pathogens, and phage Henu3 has the potential to be a new potential solution for the treatment of M. tuberculosis infection.

Orientia tsutsugamushi: An Unusual Intracellular Bacteria-Adaptation Strategies, Available Antibiotics, and Alternatives for Treatment

During evolution Orientia tsutsugamushi became a smarter obligate bacterium to establish as intracellular pathogens. O. tsutsugamushi is a human pathogenic bacterium responsible for 1 billion infections of scrub typhus. Several novel mechanisms make this bacterium unique (cell wall, genetic constitutions, secretion system, etc.). In 2007, O. tsutsugamushi Boryong was pioneer strain for whole-genome sequencing. But the fundamental biology of this bacterial cell is a mystery till date. The unusual biology makes this organism as model for host cell interaction. Only a few antibiotics are effective against this intracellular pathogen but emergence of less susceptibility toward antibiotics make the situation alarming. The review was captivated to highlight the unusual aspects of adaptation, antibiotics, and drugs beyond antibiotics.

Design of Experiment (DoE) Approach for Developing Inhalable PLGA Microparticles Loaded with Clofazimine for Tuberculosis Treatment

Tuberculosis (TB) is an airborne bacterial infection caused by Mycobacterium tuberculosis (M. tb), resulting in approximately 1.3 million deaths in 2022 worldwide. Oral therapy with anti-TB drugs often fails to achieve therapeutic concentrations at the primary infection site (lungs). In this study, we developed a dry powder inhalable formulation (DPI) of clofazimine (CFZ) to provide localized drug delivery and minimize systemic adverse effects. Poly (lactic acid-co-glycolic acid) (PLGA) microparticles (MPs) containing CFZ were developed through a single emulsion solvent evaporation technique. Clofazimine microparticles (CFZ MPs) displayed entrapment efficiency and drug loading of 66.40 ± 2.22 %w/w and 33.06 ± 1.45 µg/mg, respectively. To facilitate pulmonary administration, MPs suspension was spray-dried to yield a dry powder formulation (CFZ SD MPs). Spray drying had no influence on particle size (~1 µm), zeta potential (-31.42 mV), and entrapment efficiency. Solid state analysis (PXRD and DSC) of CFZ SD MPs studies demonstrated encapsulation of the drug in the polymer. The drug release studies showed a sustained drug release. The optimized formulation exhibited excellent aerosolization properties, suggesting effective deposition in the deeper lung region. The in vitro antibacterial studies against H37Ra revealed improved (eight-fold) efficacy of spray-dried formulation in comparison to free drug. Hence, clofazimine dry powder formulation presents immense potential for the treatment of tuberculosis with localized pulmonary delivery and improved patient compliance.

Study of adverse drug reactions during the treatment of drug resistant tuberculosis

BACKGROUND

Pharmacovigilance entails monitoring of patients for timely detection of ADR and reporting them so that more information about drug safety can be obtained. This may help in the future for dose modification or alteration of regimen. In NTEP, ADSm (Active Drug Safety monitoring) is part of pharmacovigilance. In this study we shall be studying ADRs to Anti TB drugs in DRTB.

METHODOLOGY

This study is observational, retrospective and record based, of patients admitted from 2021 to 2023 in the DOTS ward of Respiratory Medicine Department of a tertiary care hospital in Goa. Data such as age, sex, regimen, date of AKT initiation and adverse effects documented has been noted and compiled.

RESULTS

ADRs have been tabulated in the form of tables. Statistical analysis is done to find out the commonest ADR, time when they are likely to occur, which age and gender are most likely affected and if there are any other associated risk factors for ADRs.

CONCLUSION

This study will enable in future to better monitor patients with regard to particular adverse drug reaction, patient safety and if needed to alter the regimen as early as possible.

Mycobacterium tuberculosis Lineage Distribution Using Whole-Genome Sequencing and Bedaquiline, Clofazimine, and Linezolid Phenotypic Profiles among Rifampicin-Resistant Isolates from West Java, Indonesia

Tuberculosis (TB) is caused by Mycobacterium tuberculosis infection. Indonesia is ranked second in the world for TB cases. New anti-TB drugs from groups A and B, such as bedaquiline, clofazimine, and linezolid, have been shown to be effective in curing drug resistance in TB patients, and Indonesia is already using these drugs to treat patients. However, studies comparing the TB strain types with anti-TB resistance profiles are still relevant to understanding the prevalent strains in the country and their phenotypic characteristics. This study aimed to determine the association between the TB lineage distribution using whole-genome sequencing and bedaquiline, clofazimine, and linezolid phenotypic profile resistance among M. tuberculosisrifampicin-resistant isolates from West Java. M. tuberculosis isolates stock of the Department of Microbiology, Faculty of Medicine, Universitas Indonesia, was tested against bedaquiline, clofazimine, and linezolid using a mycobacteria growth indicator tube liquid culture. All isolates were tested for M. tuberculosis and rifampicin resistance using Xpert MTB/RIF. The DNA genome of M. tuberculosis was freshly extracted from a Löwenstein-Jensen medium culture and then sequenced. The isolates showed phenotypically resistance to bedaquiline, clofazimine, and linezolid at 5%, 0%, and 0%, respectively. We identified gene mutations on phenotypically bedaquiline-resistant strains (2/3), and other mutations also found in phenotypically drug-sensitive strains. Mykrobe analysis showed that most (88.33%) of the isolates could be classified as rifampicin-resistant TB. Using Mykrobe and TB-Profiler to determine the lineage distribution, the isolates were found to belong to lineage 4 (Euro-American; 48.33%), lineage 2 (East Asian/Beijing; 46.67%), and lineage 1 (Indo-Oceanic; 5%). This work underlines the requirement to increase the representation of genotype-phenotype TB data while also highlighting the importance and efficacy of WGS in predicting medication resistance and inferring disease transmission.

Relevance of NAT2 genotype and clinical factors to risk for antituberculosis drug-induced liver injury

The study analyzes the risk factors associated with antituberculosis drug-induced liver injury (ATB-DILI), and the relationship between ATB-DILI and NAT2 gene polymorphisms. Out of the 324 included patients, 57 (17.59%) developed ATB-DILI. Age, history of liver disease, alcohol consumption and timing of antituberculosis (ATB) treatment were independent risk factors for ATB-DILI in the patients with tuberculosis (TB; p < 0.05). There was a significant difference in the distribution of NAT2 metabolic phenotypes between the study group and the control group (p < 0.05). The ATB drug treatment for pulmonary TB can cause a high incidence of ATB-DILI. Age, history of liver disease, alcohol consumption and timing of ATB treatment are independent risk factors for ATB-DILI in patients with TB.

Insight into the on/off switch that regulates expression of the MSMEG-3762/63 efflux pump in Mycobacterium smegmatis

Drug resistance is one of the most difficult challenges facing tuberculosis (TB) control. Drug efflux is among the mechanisms leading to drug resistance. In our previous studies, we partially characterized the ABC-type MSMEG-3762/63 efflux pump in Mycobacterium smegmatis, which shares high percentage of identity with the Mycobacterium tuberculosis Rv1687/86c pump. MSMEG-3762/63 was shown to have extrusion activity for rifampicin and ciprofloxacin, used in first and second-line anti-TB treatments. Moreover, we described the functional role of the TetR-like MSMEG-3765 protein as a repressor of the MSMEG_3762/63/65 operon and orthologous Rv1687/86/85c in M. tuberculosis. Here we show that the operon is upregulated in the macrophage environment, supporting a previous observation of induction triggered by acid-nitrosative stress. Expression of the efflux pump was also induced by sub-inhibitory concentrations of rifampicin or ciprofloxacin. Both these drugs also prevented the binding of the MSMEG-3765 TetR repressor protein to its operator in the MSMEG_3762/63/65 operon. The hypothesis that these two drugs might be responsible for the induction of the efflux pump operon was assessed by bioinformatics analyses. Docking studies using a structural model of the regulator MSMEG-3765 showed that both antibiotics abolished the ability of this transcriptional repressor to recognize the efflux pump operon by interacting with the homodimer at different binding sites within the same binding pocket. Reduced binding of the repressor leads to induction of the efflux pump in M. smegmatis, and reduced efficacy of these two anti-mycobacterial drugs.

Tackling Drug-Resistant Tuberculosis: New Challenges from the Old Pathogen Mycobacterium tuberculosis

Antibiotics have played a crucial role in the reduction in the incidence of TB globally as evidenced by the fact that before the mid-20th century, the mortality rate within five years of the onset of the disease was 50%. The use of antibiotics has eliminated TB as a devastating disease, but the challenge of resistance to anti-TB drugs, which had already been described at the time of the introduction of streptomycin, has become a major global issue in disease management. Mismanagement of multidrug-resistant tuberculosis (MDR-TB) cases, resulting from intermittent drug use, prescription errors, and non-compliance of patients, has been identified as a critical risk factor for the development of extensively drug-resistant tuberculosis (XDR-TB). Antimicrobial resistance (AMR) in TB is a multi-factorial, complex problem of microbes evolving to escape antibiotics, the gradual decline in antibiotic development, and different economic and social conditions. In this review, we summarize recent advances in our understanding of how Mycobacterium tuberculosis evolves drug resistance. We also highlight the importance of developing shorter regimens that rapidly reach bacteria in diverse host environments, eradicating all mycobacterial populations and preventing the evolution of drug resistance. Lastly, we also emphasize that the current burden of this ancient disease is driven by a combination of complex interactions between mycobacterial and host factors, and that only a holistic approach that effectively addresses all the critical issues associated with drug resistance will limit the further spread of drug-resistant strains throughout the community.

Effect of Low Doses of Dexamethasone on Experimental Pulmonary Tuberculosis

Tuberculosis (TB) is the deadliest disease caused by a bacterial agent. Glucocorticoids (GCs) have a typical anti-inflammatory effect, but recently it has been shown that they can present proinflammatory activity, mainly by increasing molecules from innate immunity. In the current study, we evaluated the effect of low doses of dexamethasone on Mycobacterium tuberculosis in vivo and in vitro. We used an established mice model of progressing tuberculosis (TB) in the in vivo studies. Intratracheal or intranasal dexamethasone therapy administered with conventional antibiotics in the late stage of the disease decreased the lung bacilli load and lung pneumonia, and increased the survival of the animals. Finally, the treatment decreased the inflammatory response in the SNC and, therefore, sickness behavior and neurological abnormalities in the infected animals. In the in vitro experiments, we used a cell line of murine alveolar macrophages infected with Mtb. Low-dose dexamethasone treatment increased the clearance capacity of Mtb by MHS macrophages, MIP-1α, and TLR2 expression, decreased proinflammatory and anti-inflammatory cytokines, and induced apoptosis, a molecular process that contributes to the control of the mycobacteria. In conclusion, the administration of low doses of dexamethasone represents a promising adjuvant treatment for pulmonary TB.

Synthesis and Antimycobacterial Evaluation of N-(4-(Benzyloxy)benzyl)-4-aminoquinolines

Tuberculosis remains a global health problem that affects millions of people around the world. Despite recent efforts in drug development, new alternatives are required. Herein, a series of 27 N-(4-(benzyloxy)benzyl)-4-aminoquinolines were synthesized and evaluated for their ability to inhibit the M. tuberculosis H37Rv strain. Two of these compounds exhibited minimal inhibitory concentrations (MICs) similar to the first-line drug isoniazid. In addition, these hit compounds were selective for the bacillus with no significant change in viability of Vero and HepG2 cells. Finally, chemical stability, permeability and metabolic stability were also evaluated. The obtained data show that the molecular hits can be optimized aiming at the development of drug candidates for tuberculosis treatment.