Search Results (98)

Tuberculosis (TB) remains one of the leading causes of mortality worldwide, exacerbated by the emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis strains. In the pursuit of novel therapeutic strategies, thiazolidin-4-one derivatives have gained significant attention due to their structural diversity and broad-spectrum biological activities. This review provides a comprehensive summary of recent advances (2021–present) in the synthesis, structure–activity relationship (SAR), and mechanisms of action of thiazolidin-4-one derivatives as promising antitubercular agents. A detailed discussion of synthetic pathways is presented, including classical and multi-component reactions leading to various subclasses such as thiazolidine-2,4-diones, rhodanines, and pseudothiohydantoins. The SAR analysis highlights key functional groups that enhance antimycobacterial activity, such as halogen substitutions and heterocyclic linkers, while molecular docking and in vitro studies elucidate interactions with key Mtb targets including InhA, MmpL3, and DNA gyrase. Several compounds demonstrate potent inhibitory effects with MIC values lower than or comparable to first-line TB drugs, alongside favorable cytotoxicity profiles. These findings underscore the potential of thiazolidin-4-one scaffolds as a valuable platform for the development of next-generation antitubercular therapeutics. Full article

Despite continuous and extensive global efforts in the fight against tuberculosis (TB), this infectious disease continues to exert a tremendous burden on public health concerns and deaths worldwide. TB, caused by the bacterial species Mycobacterium tuberculosis, is highly frequent in people living with HIV. The continuing epidemics of both chronic infections and the emergence of antimicrobial resistance, as well as the lack of effective diagnostic tools and drug–drug interactions, pose major challenges in the fight against these pathogens. Developing a wide range of host-directed therapies may improve treatment outcomes, helping alleviate the morbidity and mortality associated with both infections. In this review, we discuss the identification and development of new host-directed strategies based on protease inhibitors and their clinical relevance as adjunctive treatment. In the context of therapeutic agents with novel mechanisms, selective protease inhibitors, including saquinavir (SQV) and cystatins (CstC and CstF), are valuable targets that may provide effective therapeutic solutions for controlling Mtb and HIV coinfection. Full article

Tuberculosis (TB) is an infectious disease caused by bacteria that primarily target the lungs. The transmission of this disease occurs through the air in the form of droplet nuclei. Unfortunately, there has been an emergence of resistance to strains of such infections, such as multidrug- as well as extensively drug-resistant strains. Healthcare workers (HCWs) are particularly vulnerable to contracting TB due to their direct contact with patients. This study aims to evaluate the knowledge, attitude, and practices among Lebanese healthcare workers towards TB and its resistant forms, particularly multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB). This study is a cross-sectional, descriptive, questionnaire-based research study that was conducted on HCWs in Lebanon. A total of 517 HCWs were included in this study. The findings displayed that 48.52% of HCWs had good knowledge of TB and MDR-TB/XDR-TB, 49.52% had average knowledge, and 2.13% had bad knowledge. Moreover, only 16.25% had a good attitude, 71.92% had an average attitude, and 11.8% had a bad attitude. Furthermore, only 14.7% had good practices, 54.74% had average practices, and 30.56% had bad practices. Having a history of testing for TB was found to be related to increased attitude. Also, the history of having TB-infected family members was found to be linked to both increased attitude and practice scores. Moreover, this study highlights the idea that high knowledge scores do not mean high attitude or high practices scores. On the same note, acceptable attitude scores do not inflict acceptable practice scores. The findings of this study showed that there is an overall good knowledge regarding TB, MDR-TB, and XDR-TB, average attitude, and average-to-bad practices. Gaps are seen in all sectors, even knowledge, especially with matters related to the diagnosis of MDR-TB/XDR-TB and its treatment duration. Also, the attitude section revealed a gap in the understanding of the modes of transmission of such an infection. Full article

Oxazolidinones, novel synthetic antibacterials, inhibit protein biosynthesis and show potent activity against Gram-positive bacteria, including Mycobacterium tuberculosis (MTB). In this study, we aimed to compare the in vitro activity of linezolid (LZD) and four oxazolidinones, including tedizolid (TZD), contezolid (CZD), sutezolid (SZD), and delpazolid (DZD), against multidrug-resistant tuberculosis (MDR-TB) and pre-extensively drug-resistant tuberculosis (pre-XDR-TB) isolates from Hainan. We established their epidemiological cut-off values (ECOFFs) using ECOFFinder software and analyzed mutations in rrl (23S rRNA), rplC, rplD, mce3R, tsnR, Rv0545c, Rv0930, Rv3331, and Rv0890c genes to uncover potential mechanisms of oxazolidinone resistance. This study included 177 MTB isolates, comprising 67 MDR and 110 pre-XDR-TB isolates. Overall, SZD exhibited the strongest antibacterial activity against clinical MTB isolates, followed by TZD and LZD, with CZD and DZD showing equivalent but weaker activity (SZD_MIC50 = TZD_MIC50 < LZD_MIC50 < CZD_MIC50 = DZD_MIC50; SZD_MIC90 < TZD_MIC90 = LZD_MIC90 < CZD_MIC90 = DZD_MIC90). Significant differences in MIC distribution were observed for TZD (p < 0.0001), CZD (p < 0.01), SZD (p < 0.0001), and DZD (p < 0.0001) compared to LZD but not between MDR-TB and pre-XDR-TB isolates. We propose the following ECOFFs: SZD, 0.5 µg/mL; LZD, TZD, and CZD, 1.0 µg/mL; DZD, 2.0 µg/mL. No statistically significant differences in resistance rates were observed among these five drugs (p > 0.05). We found that eight MTB isolates (4.52% [8/177]) resisted these five oxazolidinones. Among these, only one isolate, M26, showed an amino acid substitution (Arg79His) in the protein encoded by the rplD gene, which conferred cross-resistance to TZD and CZD. Three distinct mutations were identified in the mce3R gene; notably, isolate P604 displayed two insertions that contributed to resistance against all five oxazolidinones. However, no significant correlation was observed between mutations in the rrl, rplC, rplD, mce3R, tsnR, Rv0545c, Rv0930, Rv3331, and Rv0890c genes with oxazolidinone resistance in the clinical MTB isolates tested. In summary, this study provides the first report on the resistance of MTB in Hainan to the five oxazolidinones (LZD, TZD, CZD, SZD, and DZD). In vitro susceptibility testing indicated that SZD exhibited the strongest antibacterial activity, followed by TZD and LZD, while CZD and DZD demonstrated comparable but weaker effectiveness. Mutations in rplD and mce3R were discovered, but further research is needed to clarify their role in conferring oxazolidinone resistance in MTB. Full article

Extensively drug-resistant tuberculosis (XDR-TB) is a public health concern as drug resistance is outpacing the drug development pipeline. Alternative immunotherapeutic approaches are needed. Peripheral blood mononuclear cells (PBMCs) were isolated from pre-XDR/XDR-TB (n = 25) patients and LTBI (n = 18) participants. Thereafter, monocytic-derived dendritic cells (mo-DCs) were co-cultured with M. tb antigens, with/without a maturation cocktail (interferon-γ, interferon-α, CD40L, IL-1β, and TLR3 and TLR7/8 agonists). Two peptide pools were evaluated: (i) an ECAT peptide pool (ESAT6, CFP10, Ag85B, and TB10.4 peptides) and (ii) a PE/PPE peptide pool. Sonicated lysate of the M. tb HN878 strain served as a control. Mo-DCs were assessed for DC maturation markers, Th1 cytokines, and the ability of the DC-primed PBMCs to restrict the growth of M. tb-infected monocyte-derived macrophages. In pre-XDR/XDR-TB, mo-DCs matured with M. tb antigens (ECAT or PE/PPE peptide pool, or HN878 lysate) + cocktail, compared to mo-DCs matured with M. tb antigens only, showed higher upregulation of co-stimulatory molecules and IL-12p70 (p < 0.001 for both comparisons). The matured mo-DCs had enhanced antigen-specific CD8⁺ T-cell responses to ESAT-6 (p = 0.05) and Ag85B (p = 0.03). Containment was higher with mo-DCs matured with the PE/PPE peptide pool cocktail versus mo-DCs matured with the PE/PPE peptide pool (p = 0.0002). Mo-DCs matured with the PE/PPE peptide pool + cocktail achieved better containment than the ECAT peptide pool + cocktail [50%, (IQR:39–75) versus 46%, (IQR:15–62); p = 0.02]. In patients with pre-XDR/XDR-TB, an effector response primed by mo-DCs matured with an ECAT or PE/PPE peptide pool + cocktail was capable of restricting the growth of M. tb in vitro. Full article

Ototoxicity is a significant adverse effect associated with second-line anti-tuberculosis (TB) medications, particularly in treating extensively drug-resistant TB (XDR-TB). This study investigated the awareness of ototoxic effects among adults with XDR-TB undergoing treatment in South Africa, specifically exploring the role of information counselling on ototoxic symptoms, the timing of counselling, the content covered, and the management pathways available. This cross-sectional, descriptive qualitative study was conducted at Brooklyn Chest Hospital in the Western Cape. Ten adults with XDR-TB were purposively sampled and participated in semi-structured in-depth interviews. Data were thematically analyzed and the results revealed variability in information counselling on ototoxicity, with only 30% of participants receiving comprehensive counselling that specifically addressed ototoxic symptoms. The timing of counselling was inconsistent: while 70% of participants received some information before treatment, the remainder received counselling only after treatment initiation, which may have impacted early symptom recognition. Participants’ awareness of ototoxic symptoms was generally limited, with most identifying hearing loss but few recognizing other symptoms such as tinnitus or dizziness. Furthermore, only 20% of participants were provided with clear referral pathways for symptom management. These findings highlight a gap in the depth, timing, and specificity of information counselling on ototoxic effects for XDR-TB in this context. Several interventions can be implemented to address this gap. Full article

Mycobacterium tuberculosis (Mtb) is one of the most successful bacterial pathogens in human history. Even in the antibiotic era, Mtb is widespread and causes millions of new cases of tuberculosis each year. The ability to disrupt the host’s innate and adaptive immunity, as well as natural persistence, complicates disease control. Tuberculosis traditional therapy involves the long-term use of several antibiotics. Treatment failures are often associated with the development of resistance to one or more drugs. The development of medicines that act on new targets will expand treatment options for tuberculosis caused by multidrug-resistant or extensively drug-resistant Mtb. Therefore, the development of drugs that target virulence factors is an attractive strategy. Such medicines do not have a direct bacteriostatic or bactericidal effect, but can disarm the pathogen so that the host immune system becomes able to eliminate it. Although cell wall-associated targets are being actively studied for anti-TB drug development, other virulence factors important for adaptation and host interaction are also worth comprehensive analysis. In this review, specific Mtb virulence factors (such as secreted phosphatases, regulatory systems, and the ESX-1 secretion system) are identified as promising targets for novel anti-virulence drug development. Additionally, models for the search of virulence inhibitors are discussed, such as virtual screening in silico, in vitro enzyme inhibition assay, the use of recombinant Mtb strains with reporter constructs, phenotypic analysis using in vitro cell infection models and specific environments. Full article

Background/Objectives: Tuberculosis (TB) is preventable and curable, but multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) pose significant challenges worldwide due to the limited treatment options, lengths of therapies, and high rates of treatment failure. The management of MDR-TB has been revolutionized by all oral anti-TB drug regimens that are likely to improve adherence and treatment outcomes. These regimes include bedaquiline (B), pretomanid (P), and linezolid (L) (BPaL), and moxifloxacin if resistance to fluoroquinolones is not detected (BPaLM). Based on the evidence generated by the TB-PRACTECAL and ZeNix randomized controlled trials, BPaL/BPaLM regimens are recommended over the currently recommended longer regimens in patients with MDR-TB or monoresistance to rifampin (RR). To our knowledge, no data are currently available on the implementation of BPaL/BPaLM regimens in Italy. Results: Seventeen patients completed the BPaL/BPaLM regimen, with a treatment success rate of 90% (17/19), consistent with the literature data. Eleven patients out of the nineteen retained in care (58%) complained about symptoms consistent with adverse events (AEs). No treatment interruption was necessary due to AEs. Methods: Here, we report the real-world experience of a tertiary referral hospital for TB in Italy, from 2022 to 2024, in the management, outcomes, and adverse drug reactions of a cohort of twenty-two MDR/RR patients treated with BPaL and BPaLM regimens. Conclusions: BPaL-containing regimens also serve as promising options for patients with RR/MDR-TB in terms of real-life experience, but further multicentric studies are required in Europe to confirm the efficacy of shorter regimens to eliminate MDR TB. Full article

Tuberculosis (TB) is one of the leading causes of death due to infectious disease. It is a treatable disease; however, conventional treatment requires a lengthy treatment regimen with severe side effects, resulting in poor compliance among TB patients. Intermittent drug use, the non-compliance of patients, and prescription errors, among other factors, have led to the emergence of multidrug-resistant TB, while the mismanagement of multidrug-resistant TB (MDR-TB) has eventually led to the development of extensively drug-resistant tuberculosis (XDR-TB). Thus, there is an urgent need for new drug development, but due to the enormous expenses and time required (up to 20 years) for new drug research and development, new therapeutic approaches to TB are required. Host-directed therapies (HDT) could be a most attractive strategy, as they target the host defense processes instead of the microbe and thereby may prevent the alarming rise of MDR- and XDR-TB. This paper reviews the progress in HDT for the treatment of TB using repurposed drugs which have been investigated in clinical trials (completed or ongoing) and plant-derived natural products that are in clinical or preclinical trial stages. Additionally, this review describes the existing challenges to the development and future research directions in the implementation of HDT. Full article

Background/Objectives: Tuberculosis (TB) remains a significant global health challenge, with drug-resistant tuberculosis (DR-TB) posing a greater threat due to difficulty in treatment. This study aimed to investigate the relationship between comorbidities and treatment outcomes in patients diagnosed with DR-TB in rural Eastern Cape using logistic regression. Methods: Data on patient characteristics, comorbidities, and treatment outcomes were extracted from the medical records and analyzed using Python version 3.8. and R version 4.1.1 software. A logistic regression model was used to determine the effects of selected variables on treatment outcomes of DR-TB cases. Results: Hearing loss and hypertension (HTN) were the most frequently observed comorbidities across various DR-TB cases, particularly rifampicin-resistant (RR), multidrug-resistant (MDR), and pre-extensively drug-resistant (pre-XDR-TB) cases. A hearing loss prevalence of 5.8% (26/445) was found among patients receiving treatment for TB, with the intensity of impairment ranging from mild to severe. Gender is significantly associated with the occurrence of HTN among these patients (p-value: 0.022). Comorbidities such as epilepsy, hearing loss, and HTN significantly impact treatment success, with higher risks of mortality and incomplete cure. Using logistic regression, obesity (OR = 3.0884; e = 1.1277; p = 0.0408) and HIV-positive status (OR = 0.4458; e = 0.8078; p = 0.0001) were highly likely and less likely associated with better treatment outcomes, respectively. The logistic regression model achieved an accuracy of 64.0%, a precision of 63.0%, and a recall of 95.0%, with an F-1 score of 76.0%. Conclusions: The findings underscore the importance of implementing integrated management strategies that address both DR-TB and its comorbidities, particularly in resource-limited settings where such patients are prevalent. Public health policies should incorporate strategies to provide nutritional assessments and interventions, particularly for individuals with low BMI. This could include food supplementation programs or partnerships with local food kitchens to ensure that patients have access to adequate nutrition during DR-TB treatment. Full article

Extensive research on tuberculosis (TB) and HIV co-infection reveals the diverse prevalence and co-epidemic patterns across populations, necessitating tailored public health strategies. Co-infection is bidirectional; individuals with HIV are more susceptible to TB, and vice versa. Antiretroviral therapy (ART) and antituberculosis treatment (ATT) are critical for managing these conditions, but pose risks due to drug–pathogen and drug–drug interactions, potentially leading to immune reconstitution inflammatory syndrome (IRIS) in patients with HIV/AIDS. IRIS, often triggered by highly active antiretroviral therapy (HAART), can exacerbate HIV progression, increase drug resistance, and deteriorate patients’ quality of life. Approximately one-third of the global population with HIV is also infected with TB, with extensive drug-resistant (XDR) and multidrug-resistant (MDR) strains posing significant challenges. Latent TB infection (LTBI) further complicates the scenario, as it can progress to active TB, particularly in individuals with both conditions. The global and Indian mortality rates for TB-HIV co-infection remain high, emphasizing the need for new strategies. Additionally, unreported cases and inadequate post-treatment monitoring contribute to the high mortality rate, particularly among patients with LTBI. The complexity of managing HIV-TB co-infection, especially with LTBI, underscores the urgency of addressing these challenges to improve the outcomes for the affected populations. Full article

The management of resistant tuberculosis (tb) can be extremely difficult, especially in case of novel unpredicted complications. In this report, we present a case of a 48-year-old patient with pre-extensively drug-resistant (XDR) tb who received a treatment regimen including pretomanid, bedaquiline, linezolid, cycloserine, and amikacin and died due to myocarditis. Acquired resistance to first- and second-line drugs developed due to previous poor adherence to medication. The clinical presentation of the patient, along with her initial ultrasonographical, electrocardiogram (ECG), and laboratory examinations, were typical for acute myocarditis; however, the patient was considered unstable, and further investigations, including magnetic resonance imaging (MRI), pericardiocentesis, and endomyocardial biopsy were not performed. To our knowledge, this is the first case of myocarditis in such a patient, the clinical features of which raised a high suspicion of drug induction that could be attributed to the treatment regimen that was administered. Clinicians who manage cases of drug-resistant tb should be aware of this newly reported, potentially lethal, adverse event. 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

Drug-resistant tuberculosis (DR-TB) poses a significant public health challenge, particularly in resource-limited settings. The prevalence and management of DR-TB in African countries require comprehensive strategies to improve patient outcomes and control the spread of the disease. Aggregated routine data (from 2018 to 2022) on multidrug-resistant TB (MDR-TB) were collected from the National TB Programs (NTPs) from all six countries. The diagnostic capacity for MDR-TB was globally insufficient. The system for collecting and transporting samples was sometimes inoperative. A total of 2353 cases of MDR-TB were reported, with 86.4% receiving treatment. The gap between the expected number of MDR-TB cases and the number reported per country varied from 51.5% to 88.0%, depending on the year. Fifty-two extensively drug-resistant (XDR) TB cases received treatment regimens over five years, with variations across countries. All patients received free follow-up examinations, nutritional and financial support for travel expenses to the outpatient care and treatment centers. The MDR-TB treatment success rates for all regimens between 2018 and 2021 ranged from 44.4 to 90.9%, varying by country and year. The information system relied on primary tools, reporting tools, and digital solutions. Progress has been made in MDR-TB management; however, challenges persist, necessitating resources to enhance access to rapid molecular screening tests. Full article

According to the latest World Health Organization (WHO) report, an estimated 10.6 million people were diagnosed with tuberculosis (TB) in 2022, and 1.30 million died. A major concern is the emergence of multi-drug-resistant (MDR) and extensively drug-resistant (XDR) strains, fueled by the length of anti-TB treatment and HIV comorbidity. Innovative anti-TB agents acting with new modes of action are the only solution to counteract the spread of resistant infections. To escape starvation and survive inside macrophages, Mtb has evolved to become independent of the host by synthesizing its own amino acids. Therefore, targeting amino acid biosynthesis could subvert the ability of the mycobacterium to evade the host immune system, providing innovative avenues for drug discovery. The aim of this review is to give an overview of the most recent progress in the discovery of amino acid biosynthesis inhibitors. Among the hits discovered over the past five years, tryptophan (Trp) inhibitors stand out as the most advanced and have significantly contributed to demonstrating the feasibility of this approach for future TB drug discovery. Future efforts should be directed at prioritizing the chemical optimization of these hits to enrich the TB drug pipeline with high-quality leads. Full article