Search Results (119)

For drug-susceptible TB, the WHO-endorsed first-line regimen (isoniazid, rifampicin, ethambutol, pyrazinamide) remains the global reference. Therapy must always be tailored to drug susceptibility, especially in MDR- and XDR-TB. HIV-associated mycobacterial infections—including Mycobacterium tuberculosis (TB), disseminated Mycobacterium avium complex (MAC), and Mycobacterium leprae (M. leprae)—remain leading causes of morbidity and mortality in people living with HIV (PLWH). TB continues to account for the highest burden of AIDS-related deaths worldwide, while MAC and leprosy complicate care in advanced immunosuppression. This review synthesizes current evidence on epidemiology, clinical features, and management challenges of HIV–mycobacterial co-infections. We discuss drug-susceptible and drug-resistant TB therapies, drug–drug interactions with antiretroviral therapy (ART), and the clinical impact of immune reconstitution inflammatory syndrome (IRIS). Beyond established regimens, we highlight host-directed strategies such as metformin, glutathione augmentation, mTOR modulation, and vitamin D; immunotherapies including interferon-γ, GM-CSF, and IL-7; and therapeutic vaccines (M72/AS01E, MTBVAC, VPM1002) as promising adjuncts. Distinct from guideline-focused overviews, this review emphasizes non-tuberculous mycobacterial disease (NTM, including MAC) and leprosy in PLWH and synthesizes host-directed and adjunctive strategies with their translational prospects, including ART compatibility and IRIS. By integrating TB, NTM, and leprosy across the HIV care continuum, we highlight opportunities not treated in detail elsewhere—particularly HDT-enabled approaches and implementation considerations in PLWH. Full article

Tuberculosis (TB) is a global health challenge caused by Mycobacterium tuberculosis, with drug resistance, treatment toxicity, and treatment adherence challenges continuing to impede control efforts. The objective of this review is to explore current advancements in TB treatment, for both drug-sensitive and drug-resistant TB, focusing on pharmacologic regimens, diagnostics, and adjunctive therapies. For drug-sensitive TB, a 4-month rifapentine–moxifloxacin regimen has been proven to be non-inferior to the traditional 6-month standard, while optimized pyrazinamide dosing or faropenem substitution may improve culture conversion and reduce adverse events. In drug-resistant TB, regimens such as the bedaquiline, pretomanid, linezolid, and moxifloxacin have demonstrated efficacy with substantially shorter treatment duration; however, incidents of hepatotoxicity and linezolid-related neuropathy require careful monitoring. Adjunctive therapies, such as metformin, N-Acetylcysteine, aspirin, and statins, show promising effects in modulating host immunity and reducing long-term lung damage. Advances in diagnostics, including whole genome sequencing and CRISPR-based methods, are enabling rapid detection of resistance mutations and directed therapy. Vaccine development has advanced beyond the BCG vaccine to explore vaccines with enhanced immunogenicity or ones that are safe for immunocompromised patients. Implementation strategies such as video directly observed therapy are improving adherence; additionally, community-based, technology-supported interventions significantly improve TB knowledge and compliance. An integrated approach that combines optimized pharmacologic regimens, host-directed therapies, advanced diagnostics, and patient-centered public health strategies is essential to reduce TB incidence, long-term morbidity, and mortality. Full article

Tuberculosis (TB) is a major public health concern worldwide and in Morocco, particularly considering the increasing burden of drug-resistant Mycobacterium tuberculosis (MTB) strains. In this study, we report the first nationwide molecular characterization of MTB clinical isolates using the Deeplex-MycTB targeted next-generation sequencing (tNGS) assay. A total of 71 culture-derived DNA samples from Moroccan TB patients were analyzed to detect resistance-associated mutations across 18 genes and to determine phylogenetic lineages. Of the 68 interpretable samples, 75% harbored either confirmed or uncharacterized mutations linked to drug resistance. Among these, 78% were classified as multidrug-resistant TB (MDR-TB) including 25.5% that met the criteria for pre-extensively drug-resistant TB (pre-XDR-TB). Mutations were most frequently identified in rpoB, katG, inhA, and pncA, consistent with resistance to rifampicin, isoniazid, and pyrazinamide. Phylogenetic analysis revealed a predominance of Lineage 4.3 (Euro-American) with a high representation of the LAM9 and T clades, some of which showed associations with specific resistance profiles. These findings highlight the utility of tNGS as a powerful tool for rapid resistance detection and molecular surveillance, with potential implications for guiding individualized treatment and informing national TB control strategies in Morocco. Full article

Treatment of Mycobacterium tuberculosis requires multi-drug regimens, and resistance to any individual antibiotic can compromise outcomes. For slow-growing organisms like M. tuberculosis, rapid detection of resistance-conferring mutations enables timely initiation of effective therapy. Conversely, confirming wild-type status in resistance-associated genes supports confidence in standard regimens. We developed an amplicon-based next generation sequencing (amplicon tNGS) assay on the Illumina platform targeting eight genes linked to resistance to isoniazid, rifampin, ethambutol, pyrazinamide, and fluoroquinolones. Sequencing results were analyzed using a custom bioinformatics pipeline. Forty-seven samples were used for assay development, and 37 additional samples underwent post-implementation clinical validation. Compared to whole genome sequencing (WGS), amplicon tNGS demonstrated 97.7% sensitivity, 98.9% specificity, and 98.7% overall accuracy for variant detection in targeted regions. Resistance prediction showed 79.3% concordance with WGS; discrepancies were primarily due to mutations outside of target regions. Among post-implementation samples, 27/37 passed quality metrics for all targets, with 95.7% concordance between amplicon tNGS results and final susceptibility results. This assay is now in use in our laboratory and offers significantly faster turnaround than both WGS and phenotypic methods on cultured isolates, enabling more rapid, informed treatment decisions for tuberculosis patients. Full article

Pyrazinamide (PZA) is a key component of tuberculosis treatment, with drug resistance (PZA^R) primarily related to pncA mutations. However, discordance between phenotypic resistance and conventional pncA-based molecular diagnostics challenges diagnostic accuracy. This study investigates discrepancies between phenotypic and genotypic resistance profiles among Mycobacterium tuberculosis (Mtb) clinical isolates. Fifty-three Mtb isolates from Guangzhou Chest Hospital were tested for PZA resistance using the BACTEC MGIT 960 system and PZase activity assay. Thirty-one phenotypically PZA^R strains were genetically assessed by Sanger sequencing of PZA^R-associated customary genes. Five pncA-wild-type PZA^R strains were investigated through whole-genome sequencing. ClpC1P1P2 activity was evaluated by proteolytic degradation assay. Notably, 26/31 of the PZA^R strains harbored mutations in pncA and/or its upstream region, aligning PZase activity and phenotypic profiles. However, five PZA^R strains lacked pncA mutations. The WGS of five discordant strains revealed four novel mutations (Gly58Ser, Val63Ala, Ala567Val, and Pro796Leu) across ClpC1 domains. Incorporating clpC1 mutations improved molecular diagnostic sensitivity and accuracy from 48.3% and 69.8% (pncA alone) to 100%. This is the first report from southern China that identifies novel clpC1 mutations in wild-type pncA PZA^R Mtb isolates. Our findings underscore the limitations of pncA-targeted diagnostics and support the integration of WGS and clpC1 analysis in molecular diagnostics to prevent false-negative diagnoses and improve clinical outcomes. Full article

Background/Objectives: Isoniazid (INH) and pyrazinamide (PZA) are first-line drugs used to treat tuberculosis (TB), but their use is generally contraindicated in patients with porphyria, a group of metabolic disorders caused by defects in the heme biosynthetic pathway. To investigate the basis for these contraindications, we compared the effects of INH and PZA on the heme biosynthetic pathway in mouse liver. Method: We investigated the hepatic expression and activity of the key enzymes involved in the heme biosynthetic pathway, including aminolevulinic acid synthase 1 (Alas1) and ferrochelatase (Fech). Additionally, we employed a metabolomic approach to analyze liver and fecal samples from the mice treated with INH or PZA. Result: We found that INH, but not PZA, significantly upregulated the expression and activity of Alas1, the rate-limiting enzyme in heme biosynthesis, while concurrently downregulating Fech, which converts protoporphyrin IX (PPIX) to heme. These changes resulted in the accumulation of the toxic intermediate aminolevulinic acid (ALA) and PPIX in the liver of INH-treated mice. In contrast, PZA had no measurable effect on the expression or function of Alas1 or Fech. Conclusions: These findings provide mechanistic insight into INH-induced porphyria exacerbation and suggest that PZA may not carry the same risk, challenging its current contraindication. Full article

Background: Tuberculosis (TB) remains a leading cause of mortality worldwide, particularly in low- and middle-income countries. The rise of multidrug-resistant TB (MDR-TB) poses significant challenges to global health. This study reviews the experience of the largest pulmonology center in Serbia, a country with low MDR-TB incidence, focusing on TB prevalence, resistance detection, and treatment strategies between 2012 and 2021. Methods: We retrospectively analyzed a total of 1239 patients who were diagnosed and treated for TB in the period from 2012 to 2021 at University Clinical Center of Serbia. Results: Drug resistance was identified in 21 patients (1.7%), with the highest resistance to rifampicin (1.4%) and isoniazid (1.3%). Pyrazinamide and streptomycin resistance were detected in only a few cases. Patients with resistant TB were younger on average, though the difference was not statistically significant (46.4 ± 19.1 vs. 53.6 ± 18.4, p = 0.079). Prior TB history was more frequent in the resistant group, almost reaching statistical significance (4 vs. 82, p = 0.052). Conclusions: These findings underscore the critical importance of sustained surveillance, particularly of latent and drug-resistant TB forms, in alignment with the World Health Organization’s (WHO) TB control strategy to preserve Serbia’s low-incidence status. Moreover, given Serbia’s strategic location on a major migration route, there is an elevated risk of new TB cases emerging and potential shifts in TB-drug-resistance patterns developing in the future. Full article

Calculation of second-order derivatives of energy using the DFT method is a valuable approach for the estimation of both the thermodynamical and mechanical properties of organic crystals from the first principles. This type of calculation requires specification of several computational parameters, including the functional, supercell, and method of phonon calculations. Nevertheless, the importance of these parameters is presented in the literature very modestly. In this work, we demonstrate the influence of these computational parameters on the accuracy of calculated second-order derivatives using the practical example of pyrazinamide polymorphs, including the plastically bending α form and the β, γ, and brittle δ form. The effects of the settings used on the resulting enthalpies of the polymorphic modifications of pyrazinamide are compared: supercell setting (primitive cell vs. appropriate supercell) has a much stronger impact than functional (PBE-D3BJ vs. Hamada rev-vdW-DF2) which in turn affects results significantly more than the method for second-order derivative computation (FD vs. DFPT approach). Finally, we propose some suggestions for choosing the right settings for calculating second-order derivatives for molecular crystals. Full article

Background/Objectives: This study aims to develop a sustainable and environmentally friendly drug delivery system by synthesizing a novel drug–drug eutectic mixture (DDEM) of acetylsalicylic acid (ASA) and pyrazinamide (PZA) using a green and efficient mechanochemical approach. Methods: The DDEM was characterized using various techniques, including differential scanning calorimetry (DSC), thermogravimetry and differential thermal analysis (TG-DTA), powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), and Raman spectroscopy. Binary phase diagrams and Tammann’s triangle analysis determined the eutectic point. Density functional theory (DFT) calculations were performed on the starting compounds. The new system was evaluated for aqueous solubility, dissolution, and hygroscopicity. Results: A V-shaped binary phase diagram indicated the formation of a DDEM with a 2:1 molar ratio of ASA to PZA. A positive mixing enthalpy suggested a quasi-eutectic structure. The solubility of ASA and PZA increased by 61.5% and 85.8%, respectively, in the DDEM compared to the pure drugs. Conclusions: These findings highlight the potential of DDEMs to enhance drug properties and delivery. The synergistic interaction between ASA and PZA in the eutectic mixture may further improve therapeutic efficacy, warranting further investigation. Full article

Tuberculous meningoencephalitis is a rare manifestation of Mycobacterium tuberculosis (Mtb), with the most severe form and highest mortality. It can cause multiple complications, and treatment is difficult, as drugs cannot properly diffuse through the haemato-encephalitic barrier. We reported the case of a 17-year-old female patient who was admitted to the emergency room department with a fever for previous two weeks (up to 39 °C), dizziness, difficulty walking, and weight loss. Magnetic resonance imaging indicated possible meningoencephalitis, and a CT scan of the lungs visualised miliary infiltrates in both lungs. After repeated tests, Mtb DNA was found in the bronchial wash, cerebrospinal fluid, faeces, and urine via an Xpert/Rif Ultra test. Treatment was started with isoniazid, rifampicin, ethambutol, pyrazinamide, and corticosteroids as well. Although treatment was initiated within the first few days in the hospital, a reduction in glucocorticoid dosage worsened the patient’s neurological state, making treatment even more challenging. Prolonged use of glucocorticoids led to an improvement in the stage of the condition. Further, over time, the patient’s condition improved. Pulmonary infiltrations were not found after 2.5 months of starting therapy. Conclusions: Timely treatment is crucial for improving the prognosis of patients with miliary tuberculosis and tuberculous meningoencephalitis. Prompt recognition of symptoms and accurate diagnosis are essential to initiate effective treatment strategies. In this patient’s case, prolonged use of corticosteroids reduced neurologic complications, and ongoing treatment gradually improved the patient’s condition. Full article

Mentha longifolia (L.) L., also known as wild mint, is a perennial herbaceous plant that belongs to the Lamiaceae family. This study aimed to investigate the effects of essential oil of M. longifolia (MLEO) on oxidative stress and inflammatory responses in the liver and kidneys in the context of drug-induced liver injury caused by the anti-TB drugs rifampicin, isoniazid, and pyrazinamide (INH-RIF-PZA). The chemical composition of MLEO was characterized using GC/MS analysis, which revealed the presence of pulegone, trans-p-menthan-3-one, piperitenone, and β-caryophyllene as its major volatile constituents. An INH/RIF/PZA mixture was administered to Wistar rats for 30 days, and silymarin was administered as a standard drug. MLEO was administered p.o. at doses of 50 mg and 100 mg/kg b.w. Both doses of the MLEO therapy effectively regulated all biochemical indicators of hepatic impairment and reduced the damage caused by the INH/RIF/PZA mixture. It may be deduced that MLEO has the ability to protect organs against INH/RIF/PZA-induced damage and could potentially be a valuable natural remedy for treating anti-TB-induced liver and kidney injuries. Full article

Pyrazinamide is a first line drug used for the treatment of tuberculosis, a pathology that caused the death of more than 1.3 million people in the world during 2022, according to WHO, being a drug of current interest due to its relevance in pharmaceutical and medical sciences. In this context, solubility is one of the most important physicochemical parameters in the development and/or optimization of new pharmaceutical forms, so the present work aims to present a thermodynamic study of the solubility of pyrazinamide in nine organic solvents of pharmaceutical interest. Using the shake-flask method and UV/Vis spectrophotometry, the solubility of this drug was determined at 9 temperatures; the maximum solubility was obtained in dimethyl sulfoxide at 318.15 K ($x_2=0.0816\pm 0.004$) and the minimum in cyclohexane at 283.15 K ($1.73\pm 0.05\times {10}^{-5}$). From the apparent solubility data, the thermodynamic functions of solution and mixing were calculated, indicating an endothermic process. In addition, the solubility parameter of pyrazinamide was calculated using the Hoftyzer-van Krevelen (32.90 MPa^1/2) and Bustamante (28.14 MPa^1/2) methods. The maximum solubility was reached in dimethyl sulfoxide and the minimum in cyclohexane. As for the thermodynamic functions, the entropy drives the solution process in all cases. In relation to the solubility parameter, it can be analyzed that the mathematical models offer approximations; however, the experimental data are still primordial at the time of inferring any process. Full article

A previous study in Pará, Northern Brazil, described a strain of Mycobacterium tuberculosis with a unique genotype (SIT2517/T1) associated with multidrug-resistant tuberculosis (MDR-TB). To improve our understanding of MDR-TB transmission dynamics of these strains within this region, we performed phenotypic and genotypic drug susceptibility testing (pDST/gDST), 24-loci mycobacterial interspersed repetitive units (MIRU-VNTR) genotyping, whole-genome sequencing (WGS) and geo-epidemiology analysis. Of the 28 SIT2517/T1 isolates, 19 (67.9%) could be genotyped by 24-loci MIRU-VNTR and 15 by WGS. All belonged to sublineage 4.1.1.3, distinct from other representative Lineage 4 isolates identified in Brazil. The MDR phenotype determined by pDST was confirmed by gDST, the latter also demonstrating the presence of additional mutations conferring pre-extensively drug-resistance (pre-XDR). Discrepancies between gDST and pDST were observed for pyrazinamide and fluoroquinolones. Thirteen out of 15 isolates analyzed by WGS were clustered when applying a 12 single nucleotide polymorphisms (SNPs) cutoff. The SIT2517/T1 isolates were distributed across the metropolitan regions of Belém and Collares municipalities, showing no geographic clustering. WGS-transmission network analysis revealed a high likelihood of direct transmission and the formation of two closely linked transmission chains. This study highlights the need to implement TB genomic surveillance in the Brazilian Amazon region. Full article

The present study aims to characterise the pharmacokinetics of rifampicin (RIF) in tuberculosis (TB) patients with and without HIV co-infection, considering the formation of 25-O-desacetyl-rifampicin (desRIF). It is hypothesised that the metabolite formation, HIV co-infection and drug formulation may further explain the interindividual variation in the exposure to RIF. Pharmacokinetic, clinical, and demographic data from TB patients with (TB-HIV+ group; n = 18) or without HIV (TB-HIV− group; n = 15) who were receiving RIF as part of a four-drug fixed-dose combination (FDC) regimen (RIF, isoniazid, pyrazinamide, and ethambutol) were analysed, along with the published literature data on the relative bioavailability of different formulations. A population pharmacokinetic model, including the formation of desRIF, was developed and compared to a model based solely on the parent drug. HIV co-infection does not alter the plasma exposure to RIF and the desRIF formation does not contribute to the observed variability in the RIF disposition. The relative bioavailability and RIF plasma exposure were significantly lower than previously reported for the standard regimen with FDC tablets. Furthermore, participants weighting less than 50 kg do not reach the same RIF plasma exposure as compared to those weighting >50 kg. In conclusion, as no covariate was identified other than body weight on CL/F and Vd/F, low systemic exposure to RIF is likely to be caused by the low bioavailability of the formulation. Full article

Reliable drug susceptibility testing of pyrazinamide (PZA) is technically difficult, since PZA activity is pH sensitive. The aim of this study was to evaluate a biphasic medium assay (BMA) for the reliable detection of PZA resistance in Mycobacterium tuberculosis (MTB) using nicotinamide (NIC) as a surrogate for PZA and identifying the appropriate cut-off value for the assay. The PZA susceptibility of 122 multidrug-resistant tuberculosis (MDR-TB) isolates and 39 drug-susceptible tuberculosis (DS-TB) isolates was examined using the BMA with NIC at four different concentrations (250, 500, 1000, and 2000 mg/L) and comparing the results with results from the BACTEC MGIT 960 reference method. Out of 122 MDR-TB isolates, 40 were identified as resistant by the BACTEC MGIT 960 system, of which 92.5% contained mutations within their pncA gene plus promoter region. A minimum inhibitory concentration of NIC ≥ 1000 mg/L was used as the cut-off concentration to define resistance in correlation with the MGIT 960 outcomes. NIC-BMA had a sensitivity of 90.91%, a specificity of 100%, and an accuracy of 97.52% compared with the MGIT 960 method. NIC-BMA is a promising assay to screen PZA resistance in microbiological laboratories without automation or advanced molecular instruments. Full article