Recent updates on drug resistance in Mycobacterium tuberculosis

Toxoplasma gondii macrophage migration inhibitory factor shows anti-Mycobacterium tuberculosis potential via AZIN1/STAT1 interaction

Mycobacterium tuberculosis (MTB) is a pathogenic bacterium, belonging to the family Mycobacteriaceae, that causes tuberculosis (TB). Toxoplasma gondii macrophage migration inhibitory factor (TgMIF), a protein homolog of macrophage migration inhibitory factor, has been explored for its potential to modulate immune responses during MTB infections. We observed that TgMIF that interacts with CD74, antizyme inhibitor 1 (AZIN1), and signal transducer and activator of transcription 1 (STAT1) modulates endocytosis, restoration of mitochondrial function, and macrophage polarization, respectively. These interactions promote therapeutic efficacy in mice infected with MTB, thereby presenting a potential route to host-directed therapy development. Furthermore, TgMIF, in combination with first-line TB drugs, significantly inhibited drug-resistant MTB strains, including multidrug-resistant TB. These results demonstrate that TgMIF is potentially a multifaceted therapeutic agent against TB, acting through immune modulation, enhancement of mitochondrial function, and dependent on STAT1 and AZIN1 pathways.

Degarelix limits the survival of mycobacteria and granuloma formation

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb) infection, is a serious health hazard, characterized by tuberculous granuloma formation, which may facilitate bacterial survival. At the same time, the identification of multidrug-resistant and extremely drug-resistant Mtb strains, and the progressive accumulation of mutations in biological targets of frontline antimicrobials, has made TB treatments more difficult. Therefore, new and rapid drug development for TB is warranted. Recently, drug repurposing has received considerable attention. In this study, we applied the anticancer drug degarelix to anti-TB research and found that it inhibits mycobacteria survival and pathological damage in Mycobacterium marinum-infected zebrafish and Mtb-infected mice. Supplementation of degarelix matched the bactericidal activities of rifampicin (RFP) toward M. marinum in zebrafish. Mechanistically, degarelix significantly increased interferon (IFN)-γ levels in M. marinum-infected zebrafish. Degarelix had no direct anti-mycobacterial activity in vitro but significantly reduced the survival of H37Rv in macrophages. The effect of degarelix could be reversed by 3-methyladenine (3-MA), which inhibits the class III phosphatidylinositol (PI) 3 kinase required for autophagy initiation. However, no effect on later steps in autophagy could be detected. Our findings demonstrate the potential of degarelix on limiting mycobacterial survival and granuloma formation, which may generate novel TB therapeutics.

Revitalizing antimicrobial strategies: paromomycin and dicoumarol repurposed as potent inhibitors of M.tb's replication machinery via targeting the vital protein DnaN

Despite the WHO's recommended treatment regimen, challenges such as patient non-adherence and the emergence of drug-resistant strains persist with TB claiming 1.5 million lives annually. In this study, we propose a novel approach by targeting the DNA replication-machinery of M.tb through drug-repurposing. The β2-Sliding clamp (DnaN), a key component of this complex, emerges as a potentially vulnerable target due to its distinct structure and lack of human homology. Leveraging TBVS, we screened ∼2600 FDA-approved drugs, identifying five potential DnaN inhibitors, by employing computational studies, including molecular-docking and molecular-dynamics simulations. The shortlisted compounds were subjected to in-vitro and ex-vivo studies, evaluating their anti-mycobacterial potential. Notably, Dicoumarol, Paromomycin, and Posaconazole exhibited anti-TB properties with a MIC value of 6.25, 3.12 and 50 μg/ml respectively, with Dicoumarol and Paromomycin, demonstrating efficacy in reducing live M.tb within macrophages. Biophysical analyses confirmed the strong binding-affinity of DnaNdrug complexes, validating our in-silico predictions. Moreover, RNA-Seq data revealed the upregulation of proteins associated with DNA repair and replication mechanisms upon Paromomycin treatment. This study explores repurposing FDA-approved drugs to target TB via the mycobacterial DNA replication-machinery, showing promising inhibitory effects. It sets the stage for further clinical research, demonstrating the potential of drug repurposing in TB treatment.

Actionable mechanisms of drug tolerance and resistance in Mycobacterium tuberculosis

The emergence of antimicrobial resistance (AMR) across bacterial pathogens presents a serious threat to global health. This threat is further exacerbated in tuberculosis (TB), mainly due to a protracted treatment regimen involving a combination of drugs. A diversity of factors contributes to the emergence of drug resistance in TB, which is caused by the pathogen Mycobacterium tuberculosis (Mtb). While the traditional genetic mutation-driven drug resistance mechanisms operate in Mtb, there are also several additional unique features of drug resistance in this pathogen. Research in the past decade has enriched our understanding of such unconventional factors as efflux pumps, bacterial heterogeneity, metabolic states, and host microenvironment. Given that the discovery of new antibiotics is outpaced by the emergence of drug resistance patterns displayed by the pathogen, newer strategies for combating drug resistance are desperately needed. In the context of TB, such approaches include targeting the efflux capability of the pathogen, modulating the host environment to prevent bacterial drug tolerance, and activating the host anti-mycobacterial pathways. In this review, we discuss the traditional mechanisms of drug resistance in Mtb, newer understandings and the shaping of a set of unconventional approaches to target both the emergence and treatment of drug resistance in TB.

Development of inhaled moxifloxacin-metformin formulation as an alternative for pulmonary tuberculosis treatment

Resistant M. tuberculosis strains threaten pulmonary tuberculosis (P-TB) control since they limit drug options. Drug repositioning and new development strategies are urgently required to overcome resistance. Studies have already shown the beneficial role of the oral antidiabetic metformin as an anti-tuberculosis adjuvant drug. This work aimed to develop an inhalatory dry powder co-formulation of metformin and moxifloxacin to figure out a future option for P-TB treatment. Pre-formulation evaluations indicated the physicochemical compatibility of constituents, demonstrating powder crystallinity and acceptable drug content. Eight moxifloxacin-metformin dry powder formulations were produced by spray drying, and solid-state characterizations showed partial amorphization, ascribed to moxifloxacin. Four formulations containing L-leucine exhibited micromeritic and in vitro deposition profiles indicating pulmonary delivery suitability, like spherical and corrugated particle surface, geometric diameters < 5 μm, high emitted doses (>85 %), and mass median aerodynamic diameters between 1-5 μm. The use of a second spray dryer model further optimized the aerodynamic properties and yield of the best formulation, demonstrating the influence of the equipment used on the product obtained. Moreover, the final formulation showed high in vitro cell tolerability and characteristics in permeability studies indicative of good drug retention in the lungs.

New coumarin linked thiazole derivatives as antimycobacterial agents: Design, synthesis, enoyl acyl carrier protein reductase (InhA) inhibition and molecular modeling

Tuberculosis is a global serious problem that imposes major health, economic and social challenges worldwide. The search for new antitubercular drugs is extremely important which could be achieved via inhibition of different druggable targets. Mycobacterium tuberculosis enoyl acyl carrier protein reductase (InhA) enzyme is essential for the survival of M. tuberculosis. In this investigation, a series of coumarin based thiazole derivatives was synthesized relying on a molecular hybridization approach and was assessed against thewild typeMtb H37Rv and its mutant strain (ΔkatG) via inhibiting InhA enzyme. Among the synthesized derivatives, compounds 2b, 3i and 3j were the most potent against wild type M. tuberculosis with MIC values ranging from 6 to 8 μg/ mL and displayed low cytotoxicity towards mouse fibroblasts at concentrations 8-13 times higher than the MIC values. The three hybrids could also inhibit the growth of ΔkatGmutant strain which is resistant to isoniazid (INH). Compounds 2b and 3j were able to inhibit the growth of mycobacteria inside human macrophages, indicating their ability to penetrate human professional phagocytes. The two derivatives significantly suppress mycobacterial biofilm formation by 10-15 %. The promising target compounds were also assessed for their inhibitory effect against InhA and showed potent effectiveness with IC50 values of 0.737 and 1.494 µM, respectively. Molecular docking studies revealed that the tested compounds occupied the active site of InhA in contact with the NAD+ molecule. The 4-phenylcoumarin aromatic system showed binding interactions within the hydrophobic pocket of the active site. Furthermore, H-bond formation and π -π stacking interactions were also recorded for the promising derivatives.

Clinical application of whole-genome sequencing in the management of extensively drug-resistant tuberculosis: a case report

BACKGROUND

Whole-genome sequencing (WGS)-based prediction of drug resistance in Mycobacterium tuberculosis has the potential to guide clinical decisions in the design of optimal treatment regimens.

METHODS

We utilized WGS to investigate drug resistance mutations in a 32-year-old Tanzanian male admitted to Kibong'oto Infectious Diseases Hospital with a history of interrupted multidrug-resistant tuberculosis treatment for more than three years. Before admission, he received various all-oral bedaquiline-based multidrug-resistant tuberculosis treatment regimens with unfavourable outcomes.

RESULTS

Drug susceptibility testing of serial M. tuberculosis isolates using Mycobacterium Growth Incubator Tubes culture and WGS revealed resistance to first-line anti-TB drugs, bedaquiline, and fluoroquinolones but susceptibility to linezolid, clofazimine, and delamanid. WGS of serial cultured isolates revealed that the Beijing (Lineage 2.2.2) strain was resistant to bedaquiline, with mutations in the mmpR5 gene (Rv0678. This study also revealed the emergence of two distinct subpopulations of bedaquiline-resistant tuberculosis strains with Asp47f and Glu49fs frameshift mutations in the mmpR5 gene, which might be the underlying cause of prolonged resistance. An individualized regimen comprising bedaquiline, delamanid, pyrazinamide, ethionamide, and para-aminosalicylic acid was designed. The patient was discharged home at month 8 and is currently in the ninth month of treatment. He reported no cough, chest pain, fever, or chest tightness but still experienced numbness in his lower limbs.

CONCLUSION

We propose the incorporation of WGS in the diagnostic framework for the optimal management of patients with drug-resistant and extensively drug-resistant tuberculosis.

Unearthing phytochemicals as natural inhibitors for pantothenate synthetase in Mycobacterium tuberculosis: A computational approach

Pantothenate synthetase protein plays a pivotal role in the biosynthesis of coenzyme A (CoA), which is a crucial molecule involved in a number of cellular processes including the metabolism of fatty acid, energy production, and the synthesis of various biomolecules, which is necessary for the survival of Mycobacterium tuberculosis (Mtb). Therefore, inhibiting this protein could disrupt CoA synthesis, leading to the impairment of vital metabolic processes within the bacterium, ultimately inhibiting its growth and survival. This study employed molecular docking, structure-based virtual screening, and molecular dynamics (MD) simulation to identify promising phytochemical compounds targeting pantothenate synthetase for tuberculosis (TB) treatment. Among 239 compounds, the top three (rutin, sesamin, and catechin gallate) were selected, with binding energy values ranging from -11 to -10.3 kcal/mol, and the selected complexes showed RMSD (<3 Å) for 100 ns MD simulation time. Furthermore, molecular mechanics generalized Born surface area (MM/GBSA) binding free energy calculations affirmed the stability of these three selected phytochemicals with binding energy ranges from -82.24 ± 9.35 to -66.83 ± 4.5 kcal/mol. Hence, these identified natural plant-derived compounds as potential inhibitors of pantothenate synthetase could be used to inhibit TB infection in humans.

Rifabutin loaded inhalable β-glucan microparticle based drug delivery system for pulmonary TB

Inhalable microparticle-based anti TB drug delivery systems are being investigated extensively for Tuberculosis [TB] treatment as they offer efficient and deep lung deposition with several advantages over conventional routes. It can reduce the drug dose, treatment duration and toxic effects and optimize the drug bioavailability. Yeast derived β-glucan is a β-[1-3/1-6] linked biocompatible polymer and used as carrier for various biomolecules. Due to presence of glucan chains, particulate glucans act as PAMP and thereby gets internalized via receptor mediated phagocytosis by the macrophages. In this study, β-glucan microparticles were prepared by adding l-leucine as excipient, and exhibited 70% drug [Rifabutin] loading efficiency. Further, the sizing and SEM data of particles revealed a size of 2-4 µm with spherical dimensions. The FTIR and HPLC data confirmed the β-glucan composition and drug encapsulations efficiency of the particles. The mass median aerodynamic diameter [MMAD] and geometric standard deviation [GSD] data indicated that these particles are inhalable in nature and have better thermal stability as per DSC thermogram. These particles were found to be non-toxic upto a concentration of 80 µg/ml and were found to be readily phagocytosed by human macrophage cells in-vitro as well as in-vivo by lung alveolar macrophage. This study provides a framework for future design of inhalable β-glucan particle based host-directed drug delivery system against pulmonary TB.

Decoding drug resistance in Mycobacterium tuberculosis complex: genetic insights and future challenges

INTRODUCTION

Tuberculosis (TB), particularly its drug-resistant forms (MDR-TB and XDR-TB), continues to pose a significant global health challenge. Despite advances in treatment and diagnosis, the evolving nature of drug resistance in Mycobacterium tuberculosis (MTB) complicates TB eradication efforts. This review delves into the complexities of anti-TB drug resistance, its mechanisms, and implications on healthcare strategies globally.

AREAS COVERED

We explore the genetic underpinnings of resistance to both first-line and second-line anti-TB drugs, highlighting the role of mutations in key genes. The discussion extends to advanced diagnostic techniques, such as Whole-Genome Sequencing (WGS), CRISPR-based diagnostics and their impact on identifying and managing drug-resistant TB. Additionally, we discuss artificial intelligence applications, current treatment strategies, challenges in managing MDR-TB and XDR-TB, and the global disparities in TB treatment and control, translating to different therapeutic outcomes and have the potential to revolutionize our understanding and management of drug-resistant tuberculosis.

EXPERT OPINION

The current landscape of anti-TB drug resistance demands an integrated approach combining advanced diagnostics, novel therapeutic strategies, and global collaborative efforts. Future research should focus on understanding polygenic resistance and developing personalized medicine approaches. Policymakers must prioritize equitable access to diagnosis and treatment, enhancing TB control strategies, and support ongoing research and augmented government funding to address this critical public health issue effectively.

The effect of combining antibiotics on resistance: A systematic review and meta-analysis

When and under which conditions antibiotic combination therapy decelerates rather than accelerates resistance evolution is not well understood. We examined the effect of combining antibiotics on within-patient resistance development across various bacterial pathogens and antibiotics. We searched CENTRAL, EMBASE and PubMed for (quasi)-randomised controlled trials (RCTs) published from database inception to November 24th, 2022. Trials comparing antibiotic treatments with different numbers of antibiotics were included. A patient was considered to have acquired resistance if, at the follow-up culture, a resistant bacterium (as defined by the study authors) was detected that had not been present in the baseline culture. We combined results using a random effects model and performed meta-regression and stratified analyses. The trials' risk of bias was assessed with the Cochrane tool. 42 trials were eligible and 29, including 5054 patients, were qualified for statistical analysis. In most trials, resistance development was not the primary outcome and studies lacked power. The combined odds ratio (OR) for the acquisition of resistance comparing the group with the higher number of antibiotics with the comparison group was 1.23 (95% CI 0.68-2.25), with substantial between-study heterogeneity (I 2 =77%). We identified tentative evidence for potential beneficial or detrimental effects of antibiotic combination therapy for specific pathogens or medical conditions. The evidence for combining a higher number of antibiotics compared to fewer from RCTs is scarce and overall, is compatible with both benefit or harm. Trials powered to detect differences in resistance development or well-designed observational studies are required to clarify the impact of combination therapy on resistance.

Roles of HIF-1α signaling in Mycobacterium tuberculosis infection: New targets for anti-TB therapeutics?

Tuberculosis (TB), a deadly infectious disease induced by Mycobacterium tuberculosis (Mtb), continues to be a global public health issue that kill millions of patents every year. Despite significant efforts have been paid to identify effective TB treatments, the emergence of drug-resistant strains of the disease and the presence of comorbidities in TB patients urges us to explore the detailed mechanisms involved in TB immunity and develop more effective innovative anti-TB strategies. HIF-1α, a protein involved in regulating cellular immune responses during TB infection, has been highlighted as a promising target for the development of novel strategies for TB treatment due to its critical roles in anti-TB host immunity. This review provides a summary of current research progress on the roles of HIF-1α in TB infection, highlighting its importance in regulating the host immune response upon Mtb infection and summarizing the influences and mechanisms of HIF-1α on anti-TB immunological responses of host cells. This review also discusses the various challenges associated with developing HIF-1α as a target for anti-TB therapies, including ensuring specificity and avoiding off-target effects on normal cell function, determining the regulation and expression of HIF-1α in TB patients, and developing drugs that can inhibit HIF-1α. More deep understanding of the molecular mechanisms involved in HIF-1α signaling, its impact on TB host status, and systematic animal testing and clinical trials may benefit the optimization of HIF-1α as a novel therapeutic target for TB.

Decoding antimicrobial resistance: unraveling molecular mechanisms and targeted strategies

Antimicrobial resistance poses a significant global health threat, necessitating innovative approaches for combatting it. This review explores various mechanisms of antimicrobial resistance observed in various strains of bacteria. We examine various strategies, including antimicrobial peptides (AMPs), novel antimicrobial materials, drug delivery systems, vaccines, antibody therapies, and non-traditional antibiotic treatments. Through a comprehensive literature review, the efficacy and challenges of these strategies are evaluated. Findings reveal the potential of AMPs in combating resistance due to their unique mechanisms and lower propensity for resistance development. Additionally, novel drug delivery systems, such as nanoparticles, show promise in enhancing antibiotic efficacy and overcoming resistance mechanisms. Vaccines and antibody therapies offer preventive measures, although challenges exist in their development. Non-traditional antibiotic treatments, including CRISPR-Cas systems, present alternative approaches to combat resistance. Overall, this review underscores the importance of multifaceted strategies and coordinated global efforts to address antimicrobial resistance effectively.

Specific Mycobacterium tuberculosis Strain Circulating in Prison Revealed by Cost-Effective Amplicon Sequencing

This scientific study focuses on tuberculosis (TB) within prison settings, where persons deprived of liberty (PDL) face significantly higher rates of the disease compared to the general population. The research employs the low-cost amplicon sequencing of Mycobacterium tuberculosis strains, aiming first to identify specific lineages and also to detect mutations associated with drug resistance. The method involves multiplex amplification, DNA extraction, and sequencing, providing valuable insights into TB dynamics and resistance-mutation profiles within the prison system at an affordable cost. The study identifies a characteristic lineage (X) circulating among PDLs in the penitentiary system in Uruguay, absent in the general population, and notes its prevalence at prison entry. No high-confidence mutations associated with drug resistance were found. The findings underscore the importance of molecular epidemiology in TB control, emphasizing the potential for intra-prison transmissions and the need for broader studies to understand strain dynamics.

Unlocking InhA: Novel approaches to inhibit Mycobacterium tuberculosis

Multidrug-resistant tuberculosis continues to pose a health security risk and remains a public health emergency. Antimicrobial resistance result from treatment regimens that are both insufficient and incomplete leading to the emergence of multidrug-resistant tuberculosis, extensively drug-resistant tuberculosis and totally drug-resistant tuberculosis. The impact of tuberculosis on the people suffering from HIV (Human immunodeficiency virus infection) have resulted in the increased research efforts in designing and discovery of novel antitubercular drugs that may result in decreasing treatment duration, minimising the need for multiple drug intake, minimising cytotoxicity and enhancing the mechanism of action of drug. While many drugs are available to treat tuberculosis, a precise and timely cure is still absent. Consequently, further investigation is needed to identify more recent molecular equivalents that have the potential to swiftly remove this disease. Isoniazid (INH), a treatment for tuberculosis (TB), targets the enzyme InhA (mycobacterium enoyl acyl carrier protein reductase), the Mycobacterium tuberculosis enoyl-acyl carrier protein (ACP) reductase, most common INH resistance is circumvented by InhA inhibitors that do not require KatG (catalase-peroxidase) activation, as a result, researchers are trying to work in the area of development of InhA inhibitors which could help in eradicating the era of tuberculosis from the world.

Development of a self-microemulsifying drug delivery system to deliver delamanid via a pressurized metered dose inhaler for treatment of multi-drug resistant pulmonary tuberculosis

Tuberculosis (TB) is a serious health issue that contributes to millions of deaths throughout the world and increases the threat of serious pulmonary infections in patients with respiratory illness. Delamanid is a novel drug approved in 2014 to deal with multi-drug resistant TB (MDR-TB). Despite its high efficiency in TB treatment, delamanid poses delivery challenges due to poor water solubility leading to inadequate absorption upon oral administration. This study involves the development of novel formulation-based pressurized metered dose inhalers (pMDIs) containing self-microemulsifying mixtures of delamanid for efficient delivery to the lungs. To identify the appropriate self-microemulsifying formulations, ternary diagrams were plotted using different combinations of surfactant to co-surfactant ratios (1:1, 2:1, and 3:1). The combinations used Cremophor RH40, Poly Ethylene Glycol 400 (PEG 400), and peppermint oil, and those that showed the maximum microemulsion region and rapid and stable emulsification were selected for further characterization. The diluted self-microemulsifying mixtures underwent evaluation of dose uniformity, droplet size, zeta potential, and transmission electron microscopy. The selected formulations exhibited uniform delivery of the dose throughout the canister life, along with droplet sizes and zeta potentials that ranged from 24.74 to 88.99 nm and - 19.27 to - 10.00 mV, respectively. The aerosol performance of each self-microemulsifying drug delivery system (SMEDDS)-pMDI was assessed using the Next Generation Impactor, which indicated their capability to deliver the drug to the deeper areas of the lungs. In vitro cytotoxicity testing on A549 and NCI-H358 cells revealed no significant signs of toxicity up to a concentration of 1.56 µg/mL. The antimycobacterial activity of the formulations was evaluated against Mycobacterium bovis using flow cytometry analysis, which showed complete inhibition by day 5 with a minimum bactericidal concentration of 0.313 µg/mL. Moreover, the cellular uptake studies showed efficient delivery of the formulations inside macrophage cells, which indicated the potential for intracellular antimycobacterial activity. These findings demonstrated the potential of the Delamanid-SMEDDS-pMDI for efficient pulmonary delivery of delamanid to improve its effectiveness in the treatment of multi-drug resistant pulmonary TB.

Impact of MSMEG5257 Deletion on Mycolicibacterium smegmatis Growth

Mycobacterial membrane proteins play a pivotal role in the bacterial invasion of host cells; however, the precise mechanisms underlying certain membrane proteins remain elusive. Mycolicibacterium smegmatis (Ms) msmeg5257 is a hemolysin III family protein that is homologous to Mycobacterium tuberculosis (Mtb) Rv1085c, but it has an unclear function in growth. To address this issue, we utilized the CRISPR/Cas9 gene editor to construct Δmsmeg5257 strains and combined RNA transcription and LC-MS/MS protein profiling to determine the functional role of msmeg5257 in Ms growth. The correlative analysis showed that the deletion of msmeg5257 inhibits ABC transporters in the cytomembrane and inhibits the biosynthesis of amino acids in the cell wall. Corresponding to these results, we confirmed that MSMEG5257 localizes in the cytomembrane via subcellular fractionation and also plays a role in facilitating the transport of iron ions in environments with low iron levels. Our data provide insights that msmeg5257 plays a role in maintaining Ms metabolic homeostasis, and the deletion of msmeg5257 significantly impacts the growth rate of Ms. Furthermore, msmeg5257, a promising drug target, offers a direction for the development of novel therapeutic strategies against mycobacterial diseases.

Novel strategies based on natural products and synthetic derivatives to overcome resistance in Mycobacterium tuberculosis

One of the biggest health challenges of today's world is the emergence of antimicrobial resistance (AMR), which renders conventional therapeutics insufficient and urgently demands the generation of novel antimicrobial strategies. Mycobacterium tuberculosis (M. tuberculosis), the pathogen causing tuberculosis (TB), is among the most successful bacteria producing drug-resistant infections. The versatility of M. tuberculosis allows it to evade traditional anti-TB agents through various acquired and intrinsic mechanisms, rendering TB among the leading causes of infectious disease-related mortality. In this context, researchers worldwide focused on establishing novel approaches to address drug resistance in M. tuberculosis, developing diverse alternative treatments with varying effectiveness and in different testing phases. Overviewing the current progress, this paper aims to briefly present the mechanisms involved in M. tuberculosis drug-resistance, further reviewing in more detail the under-development antibiotics, nanotechnological approaches, and natural therapeutic solutions that promise to overcome current treatment limitations.

Correlation between serum isoniazid concentration and therapeutic response in patients of pulmonary tuberculosis in Central India: A prospective observational study

BACKGROUND

Tuberculosis (TB), an infectious disease caused by Mycobacterium tuberculosis is one of the top ten causes of death worldwide. Isoniazid (INH) is an important component of anti-tuberculosis therapy (ATT). Low isoniazid levels can serve as a risk factor for the development of treatment failure, relapse of disease and acquired secondary resistance. Hence, serum level of isoniazid becomes a critical factor in determining the treatment outcome of patients on ATT. This study aimed to evaluate the correlation between serum isoniazid concentration and therapeutic response in patients of pulmonary tuberculosis in Central India.

METHODS

This was a prospective single cohort observational study conducted at a tertiary care hospital. Therapeutic response in newly diagnosed patients of pulmonary TB was determined based the microbiological, clinical and radiological parameters. Serum INH levels were estimated based on a spectrophotometric method using nano-spectrophotometer.

RESULTS

In this study, patients had a significant improvement in treatment outcome as evident by a significant decrease in the TB score I at end of IP (p = 0.001) and a significant decline in the Timika score at end of CP (p = 0.001). Although all patients converted to sputum negative at end of CP, 20% remained positive at end of IP. Lower INH levels were seen in 13.3% of the study population. Higher INH levels were observed in sputum converters, patients with low TB score I and low Timika score, although no statistically significant difference was noted (p > 0.05).

CONCLUSION

In this study, we could not find any statistically significant association between serum INH levels and therapeutic outcome of the patients. Further studies on a larger population could provide better understanding about the prevalence of low serum isoniazid levels among the Indian population and establish its relationship with therapeutic outcome. Also, the usage of a comparatively less expensive spectrophotometric method of analysis makes this feasible in almost every district hospital without the need of high-performance liquid chromatography which is costlier and needs more expertise.

Factors Associated with Non-Adherence to Treatment Among Migrants with MDR-TB in Wuhan, China: A Cross-Sectional Study

Background

Multidrug resistant tuberculosis (MDR-TB) has attracted increasing attention in achieving the global goal of tuberculosis (TB) control. China has the second largest TB burden worldwide and has been experiencing large-scale domestic migration. This study aims to explore the effect of migrants on non-adherence to MDR-TB treatment.

Materials and Methods

A cross-sectional study was carried out in Wuhan, China. The exposure cases were migrants who were not locally registered in the residence registration system. The control cases were local residents. Non-adherence cases were patients who were lost follow-up or refused treatment. Chi-square and t-test were used to compare variables between migrants and local residents. Logistic regression models using enter method were used to determine the relationship between migration and non-adherence to treatment. Moderation and medication effects on the association between migrant status and non-adherence were also explored.

Results

We studied 73 migrants and 219 local residents. The migrants, who did not to adhere to treatment (55, 75.3%), was far higher than that of local residents (89, 40.6%). Migrants with MDR-TB had 10.38-times higher difficulty in adhering to treatment (adjusted OR = 10.38, 95% CI 4.62-25.28) than local residents. This additional likelihood was moderated by age and treatment registration group. Migration had an indirect association with non-adherence to treatment via social medial insurance (adjusted OR = 1.05, 95% CI 1.01-1.13).

Conclusion

There a significant increased likelihood of non-adherence to treatment among migrants with MDR-TB, highlighting the importance of improving treatment adherence in this population. Migration prevented migrants from gaining access to social medical insurance and indirectly reduced their likelihood of adherence to treatment.

Targeting of essential mycobacterial replication enzyme DnaG primase revealed Mitoxantrone and Vapreotide as novel mycobacterial growth inhibitors

Tuberculosis (TB) is the second leading cause of mortality after COVID-19, with a global death toll of 1.6 million in 2021. The escalating situation of drug-resistant forms of TB has threatened the current TB management strategies. New therapeutics with novel mechanisms of action are urgently required to address the current global TB crisis. The essential mycobacterial primase DnaG with no structural homology to homo sapiens presents itself as a good candidate for drug targeting. In the present study, Mitoxantrone and Vapreotide, two FDA-approved drugs, were identified as potential anti-mycobacterial agents. Both Mitoxantrone and Vapreotide exhibit a strong Minimum Inhibitory Concentration (MIC) of ≤25μg/ml against both the virulent (M.tb-H37Rv) and avirulent (M.tb-H37Ra) strains of M.tb. Extending the validations further revealed the inhibitory potential drugs in ex vivo conditions. Leveraging the computational high-throughput multi-level docking procedures from the pool of ~2700 FDA-approved compounds, Mitoxantrone and Vapreotide were screened out as potential inhibitors of DnaG. Extensive 200 ns long all-atoms molecular dynamic simulation of DnaGDrugs complexes revealed that both drugs bind strongly and stabilize the DnaG during simulations. Reduced solvent exposure and confined motions of the active centre of DnaG upon complexation with drugs indicated that both drugs led to the closure of the active site of DnaG. From this study's findings, we propose Mitoxantrone and Vapreotide as potential anti-mycobacterial agents, with their novel mechanism of action against mycobacterial DnaG.

Statistical and network analyses reveal mechanisms for the enhancement of macrophage immunity by manganese in Mycobacterium tuberculosis infection

Tuberculosis is a significant infectious disease that poses a serious risk to human health. Our previous research has indicated that manganese ions reduce the bacterial load of Mycobacterium tuberculosis in macrophages, but the exact immune defense mechanism remains unknown. Several critical proteins and pathways involved in the host's immune response during this process are still unidentified. Our research aims to identify these proteins and pathways and provide a rationale for the use of manganese ions in the adjuvant treatment of tuberculosis. We downloaded GSE211666 data from the GEO database and selected the RM (Post-infection manganese ion treatment group) and Ra (single-infection group) groups for comparison and analysis to identify differential genes. These differential genes were then enriched and analyzed using STRING, Cytoscape, and NDEx tools to identify the two most relevant pathways of the "Host Response Signature Network." After conducting an in-depth analysis of these two pathways, we found that manganese ions mainly mediate (1) the interferon -gamma (IFN-γ) and its receptor IFNGR and the downstream JAK-STAT pathway and (2) the NFκB pathway to enhance macrophage response to interferon, autophagy, polarization, and cytokine release. Using qPCR experiments, we verified the increased expression of CXCL10, MHCII, IFNγ, CSF2, and IL12, all of which are cytokines that play a key role in resistance to Mycobacterium tuberculosis infection, suggesting that macrophages enter a state of pro-inflammatory and activation after the addition of manganese ions, which enhances their immunosuppressive effect against Mycobacterium tuberculosis. We conclude that our study provides evidence of manganese ion's ability to treat tuberculosis adjuvantly.

Synthesis and Characterization of New N-acyl Hydrazone Derivatives of Carprofen as Potential Tuberculostatic Agents

N-acyl hydrazone (NAH) is recognized as a promising framework in drug design due to its versatility, straightforward synthesis, and attractive range of biological activities, including antimicrobial, antitumoral, analgesic, and anti-inflammatory properties. In the global context of increasing resistance of pathogenic bacteria to antibiotics, NAHs represent potential solutions for developing improved treatment alternatives. Therefore, this research introduces six novel derivatives of (EZ)-N'-benzylidene-2-(6-chloro-9H-carbazol-2-yl)propanehydrazide, synthesized using a microwave-assisted method. In more detail, we joined two pharmacophore fragments in a single molecule, represented by an NSAID-type carprofen structure and a hydrazone-type structure, obtaining a new series of NSAID-N-acyl hydrazone derivatives that were further characterized spectrally using FT-IR, NMR, and HRMS investigations. Additionally, the substances were assessed for their tuberculostatic activity by examining their impact on four strains of M. tuberculosis, including two susceptible to rifampicin (RIF) and isoniazid (INH), one susceptible to RIF and resistant to INH, and one resistant to both RIF and INH. The results of our research highlight the potential of the prepared compounds in fighting against antibiotic-resistant M. tuberculosis strains.

Trends of Mycobacterium tuberculosis and Rifampicin resistance in Northwest Ethiopia: Xpert® MTB/RIF assay results from 2015 to 2021

BACKGROUND

Tuberculosis (TB) remains one of the leading causes of morbidity and mortality worldwide, particularly in countries with limited resources. The emergence of drug resistance in mycobacterium tuberculosis (MTB), particularly rifampicin (RIF) resistance, hindered TB control efforts. Continuous surveillance and regular monitoring of drug-resistant TB, including rifampicin resistance (RR), are required for effective TB intervention strategies and prevention and control measures.

OBJECTIVE

Determine the trend of TB and RR-TB among presumptive TB patients in Northwest Ethiopia.

METHOD

A retrospective study was conducted at the University of Gondar Comprehensive Specialized Hospital (UoG-CSH). The study included TB registration logbook data from all patients who visited the hospital and were tested for MTB using the Xpert® MTB/RIF assay between 2015 and 2021. The SPSS version 26 software was used to enter, clean, and analyze the laboratory-based data.

RESULTS

A total of 18,787 patient results were included, with 93.8% (17,615/18787) of them being successful, meaning they were not invalid, error, or aborted. About 10.5% (1846/17615) of the 17,615 results were MTB-positive, with 7.42% (137/1846) RIF resistant. Age, anti-TB treatment history, and diagnosis year were associated with the presence of MTB and RR-MTB. Tuberculosis (TB) prevalence was higher in productive age groups, whereas RR-TB prevalence was higher in the elderly. Regarding diagnosis year, the prevalence of TB and RR-TB showed a declining trend as the year progressed. While MTB was detected in 12.8% (471/3669) of new and 22.2% (151/679) of re-treatment presumptive TB patients, RR-MTB was detected in 8.5% (40/471) of new and 18.5% (28/151) of re-treatment TB cases.

CONCLUSION

The prevalence of TB and RR-TB in the study area showed a declining trend over the years. While TB was more prevalent in productive age groups (15 to 45 years), RR-TB was more prevalent in older populations (over 45 years), than others. Moreover, patients with a history of anti-TB drug exposure were more likely to be positive for DR-TB, highlighting the need to strengthen DOT programs for proper management of TB treatment.

Unraveling Dilemmas and Lacunae in the Escalating Drug Resistance of Mycobacterium tuberculosis to Bedaquiline, Delamanid, and Pretomanid

Delamanid, bedaquiline, and pretomanid have been recently added in the anti-tuberculosis (anti-TB) treatment regimens and have emerged as potential solutions for combating drug-resistant TB. These drugs have proven to be effective in treating drug-resistant TB when used in combination. However, concerns have been raised about the eventual loss of these drugs due to evolving resistance mechanisms and certain adverse effects such as prolonged QT period, gastrointestinal problems, hepatotoxicity, and renal disorders. This Perspective emphasizes the properties of these first-in-class drugs, including their mechanism of action, pharmacokinetics/pharmacodynamics profiles, clinical studies, adverse events, and underlying resistance mechanisms. A brief coverage of efforts toward the generation of best-in-class leads in each class is also provided. The ongoing clinical trials of new combinations of these drugs are discussed, thus providing a better insight into the use of these drugs while designing an effective treatment regimen for resistant TB cases.

Discovery of N-(1-(6-Oxo-1,6-dihydropyrimidine)-pyrazole) Acetamide Derivatives as Novel Noncovalent DprE1 Inhibitors against Mycobacterium tuberculosis

Decaprenylphosphoryl-β-d-ribose oxidase (DprE1) is a promising target for treating tuberculosis (TB). Currently, most novel DprE1 inhibitors are discovered through high-throughput screening, while computer-aided drug design (CADD) strategies are expected to promote the discovery process. In this study, with the aid of structure-based virtual screening and computationally guided design, a series of novel scaffold N-(1-(6-oxo-1,6-dihydropyrimidine)-pyrazole) acetamide derivatives with significant antimycobacterial activities were identified. Among them, compounds LK-60 and LK-75 are capable of effectively suppressing the proliferation of Mtb with MICMtb values of 0.78-1.56 μM, comparable with isoniazid and much superior to the phase II candidate TBA-7371 (MICMtb = 12.5 μM). LK-60 is also the most active DprE1 inhibitor derived from CADD so far. Further studies confirmed their high affinity to DprE1, good safety profiles to gut microbiota and human cells, and synergy effects with either rifampicin or ethambutol, indicating their broad potential for clinical applications.

Prevalence, Transmission and Genetic Diversity of Pyrazinamide Resistance Among Multidrug-Resistant Mycobacterium tuberculosis Isolates in Hunan, China

Background

China is a country with a burden of high rates of both TB and multidrug-resistant TB (MDR-TB). However, published data on pyrazinamide (PZA) resistance are still limited in Hunan province, China. This study investigated the prevalence, transmission, and genetic diversity of PZA resistance among multidrug-resistant Mycobacterium tuberculosis isolates in Hunan province.

Methods

Drug susceptibility testing (DST) with the Bactec MGIT 960 PZA kit and pyrazinamidase (PZase) testing were conducted on all 298 MDR clinical isolates. Moreover, 24-locus MIRU-VNTR and DNA sequencing of pncA, rpsA, and panD genes were conducted on 180 PZA-resistant (PZA-R) isolates.

Results

The prevalence of PZA resistance among MDR-TB strains reached 60.4%. Newly diagnosed PZA-R TB patients and clustered isolates with identical pncA, rpsA, and panD mutations showed that transmission of PZA-R isolates played a significant role in the formation of PZA-R TB. Ninety-eight mutation patterns were observed in the pncA among 180 PZA-R isolates, and seventy-one (72.4%) were point mutations. Twenty-four of these mutations are new, including 2 base substitutions (V93G and T153S) and 22 nucleotide deletions or insertions. The W119C was found in PZA-S isolates, on the other hand, F94L and V155A mutations were found in both PZA resistant and susceptible isolates with positive PZase activity, indicating that they were not associated with PZA resistance. This is not entirely in line with the WHO catalogue. Ten novel rpsA mutations were found in 10 PZA-R isolates, which all combined with mutations in pncA. Thus, it is unpredictable whether these mutations in rpsA can impact PZA resistance. No panD mutation was found in all PZA-R isolates.

Conclusion

DNA sequencing of pncA and PZase activity testing have great potential in predicting PZA resistance.

The Interplay between Mycobacterium tuberculosis and Human Microbiome

Tuberculosis (TB), a respiratory disease caused by Mycobacterium tuberculosis (Mtb), is a significant cause of mortality worldwide. The lung, a breeding ground for Mtb, was once thought to be a sterile environment, but has now been found to host its own profile of microbes. These microbes are critical in the development of the host immune system and can produce metabolites that aid in host defense against various pathogens. Mtb infection as well as antibiotics can shift the microbial profile, causing dysbiosis and dampening the host immune response. Additionally, increasing cases of drug resistant TB have impacted the success rates of the traditional therapies of isoniazid, rifampin, pyrazinamide, and ethambutol. Recent years have produced tremendous research into the human microbiome and its role in contributing to or attenuating disease processes. Potential treatments aimed at altering the gut-lung bacterial axis may offer promising results against drug resistant TB and help mitigate the effects of TB.

Metabolic Rewiring of Mycobacterium tuberculosis upon Drug Treatment and Antibiotics Resistance

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a significant global health challenge, further compounded by the issue of antimicrobial resistance (AMR). AMR is a result of several system-level molecular rearrangements enabling bacteria to evolve with better survival capacities: metabolic rewiring is one of them. In this review, we present a detailed analysis of the metabolic rewiring of Mtb in response to anti-TB drugs and elucidate the dynamic mechanisms of bacterial metabolism contributing to drug efficacy and resistance. We have discussed the current state of AMR, its role in the prevalence of the disease, and the limitations of current anti-TB drug regimens. Further, the concept of metabolic rewiring is defined, underscoring its relevance in understanding drug resistance and the biotransformation of drugs by Mtb. The review proceeds to discuss the metabolic adaptations of Mtb to drug treatment, and the pleiotropic effects of anti-TB drugs on Mtb metabolism. Next, the association between metabolic changes and antimycobacterial resistance, including intrinsic and acquired drug resistance, is discussed. The review concludes by summarizing the challenges of anti-TB treatment from a metabolic viewpoint, justifying the need for this discussion in the context of novel drug discovery, repositioning, and repurposing to control AMR in TB.

Redefining Peptide 14D: Substitutional Analysis for Accelerated TB Diagnosis and Enhanced Activity against Mycobacterium tuberculosis

Tuberculosis (TB) caused by Mycobacterium tuberculosis remains a predominant cause of mortality, especially in low- and middle-income nations. Recently, antimicrobial peptides have been discovered that at low concentrations could stimulate the growth of M. tuberculosis (hormetic response). In this study, such a peptide was used to investigate the effects on the time to positivity (TTP). A systematic substitution analysis of peptide 14D was synthesized using Spot synthesis technology, resulting in 171 novel peptides. Our findings revealed a spectrum of interactions, with some peptides accelerating M. tuberculosis growth, potentially aiding in faster diagnostics, while others exhibited inhibitory effects. Notably, peptide NH2-wkivfiwrr-CONH2 significantly reduced the TTP by 25 h compared to the wild-type peptide 14D, highlighting its potential in improving TB diagnostics by culture. Several peptides demonstrated potent antimycobacterial activity, with a minimum inhibitory concentration (MIC) of 20 µg/mL against H37Rv and a multidrug-resistant M. tuberculosis strain. Additionally, for two peptides, a strongly diminished formation of cord-like structures was observed, which is indicative of reduced virulence and transmission potential. This study underscores the multifaceted roles of antimicrobial peptides in TB management, from enhancing diagnostic efficiency to offering therapeutic avenues against M. tuberculosis.

Evaluation of mycobacteria infection prevalence and optimization of the identification process in North Sardinia, Italy

IMPORTANCE

Mycobacterial infection is a major threat to public health worldwide. Accurate identification of infected species and drug resistance detection are critical factors in treatment. We focused on shortening the turn-around time of identifying mycobacteria species and antibiotic resistance tests.

Host-directed therapy against mycobacterium tuberculosis infections with diabetes mellitus

Tuberculosis (TB) is caused by the bacterial pathogen Mycobacterium tuberculosis (MTB) and is one of the principal reasons for mortality and morbidity worldwide. Currently, recommended anti-tuberculosis drugs include isoniazid, rifampicin, ethambutol, and pyrazinamide. TB treatment is lengthy and inflicted with severe side-effects, including reduced patient compliance with treatment and promotion of drug-resistant strains. TB is also prone to other concomitant diseases such as diabetes and HIV. These drug-resistant and complex co-morbid characteristics increase the complexity of treating MTB. Host-directed therapy (HDT), which effectively eliminates MTB and minimizes inflammatory tissue damage, primarily by targeting the immune system, is currently an attractive complementary approach. The drugs used for HDT are repositioned drugs in actual clinical practice with relative safety and efficacy assurance. HDT is a potentially effective therapeutic intervention for the treatment of MTB and diabetic MTB, and can compensate for the shortcomings of current TB therapies, including the reduction of drug resistance and modulation of immune response. Here, we summarize the state-of-the-art roles and mechanisms of HDT in immune modulation and treatment of MTB, with a special focus on the role of HDT in diabetic MTB, to emphasize the potential of HDT in controlling MTB infection.

Impacts of body weight change on treatment outcomes in patients with multidrug-resistant tuberculosis in Northwest Ethiopia

Measuring body weight during therapy has received insufficient attention in poor resource settings like Ethiopia. We aimed to investigate the association between weight change during therapy and treatment outcomes among patients with multidrug-resistant tuberculosis (MDR-TB) in northwest Ethiopia. This retrospective cohort study analysed data from patients with MDR-TB admitted between May 2015 to February 2022 at four treatment facilities in Northwest Ethiopia. We used the joint model (JM) to determine the association between weight change during therapy and treatment outcomes for patients with MDR-TB. A total of 419 patients with MDR-TB were included in the analysis. Of these, 265 (63.3%) were male, and 255 (60.9%) were undernourished. Weight increase over time was associated with a decrease in unsuccessful treatment outcomes (adjusted hazard ratio (AHR): 0.96, 95% CI: 0.94 to 0.98). In addition, patients with undernutrition (AHR: 1.72, 95% CI: 1.10 to 2.97), HIV (AHR:1.79, 95% CI: 1.04 to 3.06), and clinical complications such as pneumothorax (AHR: 1.66, 95% CI: 1.03 to 2.67) were associated with unsuccessful treatment outcomes. The JM showed a significant inverse association between weight gain and unsuccessful MDR-TB treatment outcomes. Therefore, weight gain may be used as a surrogate marker for good TB treatment response in Ethiopia.

In silico Screening of Food and Drug Administration-approved Compounds against Trehalose 2-sulfotransferase (Rv0295c) in Mycobacterium tuberculosis: Insights from Molecular Docking and Dynamics Simulations

BACKGROUND

Tuberculosis (TB) remains a prominent global health challenge, distinguished by substantial occurrences of infection and death. The upsurge of drug-resistant TB strains underscores the urgency to identify novel therapeutic targets and repurpose existing compounds. Rv0295c is a potentially druggable enzyme involved in cell wall biosynthesis and virulence. We evaluated the inhibitory activity of Food and Drug Administration (FDA)-approved compounds against Rv0295c of Mycobacterium tuberculosis, employing molecular docking, ADME evaluation, and dynamics simulations.

METHODS

The study screened 1800 FDA-approved compounds and selected the top five compounds with the highest docking scores. Following this, we subjected the initially screened ligands to ADME analysis based on their dock scores. In addition, the compound exhibited the highest binding affinity chosen for molecular dynamics (MD) simulation to investigate the dynamic behavior of the ligand-receptor complex.

RESULTS

Dihydroergotamine (CHEMBL1732) exhibited the highest binding affinity (-12.8 kcal/mol) for Rv0295c within this set of compounds. We evaluated the stability and binding modes of the complex over extended simulation trajectories.

CONCLUSION

Our in silico analysis demonstrates that FDA-approved drugs can serve as potential Rv0295c inhibitors through repurposing. The combination of molecular docking and MD simulation offers a comprehensive understanding of the interactions between ligands and the protein target, providing valuable guidance for further experimental validation. Identifying Rv0295c inhibitors may contribute to new anti-TB drugs.

Host-Pathogen Interaction: Biology and Public Health

Interactions between host and pathogenic microorganisms are common in nature and have a significant impact on host health, often leading to several types of infections. These interactions have evolved as a result of the ongoing battle between the host's defense mechanisms and the pathogens' invasion strategies. In this chapter, we will explore the evolution of host-pathogen interactions, explore their molecular mechanisms, examine the different stages of interaction, and discuss the development of pharmacological treatments. Understanding these interactions is crucial for improving public health, as it enables us to develop effective strategies to prevent and control infectious diseases. By gaining insights into the intricate dynamics between pathogens and their hosts, we can work towards reducing the burden of such diseases on society.

The impact of different antibiotic injection regimens on patients with severe infections: A meta-analysis

Severe infection is a critical health threat to humans, and antibiotic treatment is one of the main therapeutic approaches. Nevertheless, the efficacy of various antibiotic injection regimens in severe infection patients remains uncertain. This study aimed to comprehensively evaluate the impact of various antibiotic injection strategies on patients with severe infection through a meta-analysis. Relevant research literature was collected by searching databases such as PubMed, Embase, and Cochrane Library. The retrieved literature was screened according to inclusion and exclusion criteria. Relevant data, including study design, sample size, and antibiotic regimens, were extracted from the included studies. The Cochrane Collaboration's Risk of Bias tool was employed to assess the risk of bias in each study. Statistical analysis was performed based on the results of the included studies. A total of 15 articles were included, covering various types of severe infection patients, including pulmonary and abdominal infections. The analysis provided insights into mortality rates, treatment efficacy, adverse reactions (ARs), Acute Physiology and Chronic Health Evaluation (APACHE) scores, among other outcomes. The results indicated that combination therapy was superior to monotherapy in terms of mortality rate, treatment efficacy, and APACHE scores, while the incidence of ARs was lower in the monotherapy group compared to the combination therapy group (p < 0.05). Combination therapy showed better treatment efficacy compared to monotherapy, although it was associated with a higher incidence of ARs.

Micro-nanoemulsion and nanoparticle-assisted drug delivery against drug-resistant tuberculosis: recent developments

Tuberculosis (TB) is a major global health problem and the second most prevalent infectious killer after COVID-19. It is caused by Mycobacterium tuberculosis (Mtb) and has become increasingly challenging to treat due to drug resistance. The World Health Organization declared TB a global health emergency in 1993. Drug resistance in TB is driven by mutations in the bacterial genome that can be influenced by prolonged drug exposure and poor patient adherence. The development of drug-resistant forms of TB, such as multidrug resistant, extensively drug resistant, and totally drug resistant, poses significant therapeutic challenges. Researchers are exploring new drugs and novel drug delivery systems, such as nanotechnology-based therapies, to combat drug resistance. Nanodrug delivery offers targeted and precise drug delivery, improves treatment efficacy, and reduces adverse effects. Along with nanoscale drug delivery, a new generation of antibiotics with potent therapeutic efficacy, drug repurposing, and new treatment regimens (combinations) that can tackle the problem of drug resistance in a shorter duration could be promising therapies in clinical settings. However, the clinical translation of nanomedicines faces challenges such as safety, large-scale production, regulatory frameworks, and intellectual property issues. In this review, we present the current status, most recent findings, challenges, and limiting barriers to the use of emulsions and nanoparticles against drug-resistant TB.

A precision overview of genomic resistance screening in Ecuadorian isolates of Mycobacterium tuberculosis using web-based bioinformatics tools

INTRODUCTION

Tuberculosis (TB) is among the deadliest diseases worldwide, and its impact is mainly due to the continuous emergence of resistant isolates during treatment due to the laborious process of resistance diagnosis, nonadherence to treatment and circulation of previously resistant isolates of Mycobacterium tuberculosis. In this study, we evaluated the performance and functionalities of web-based tools, including Mykrobe, TB-profiler, PhyResSE, KvarQ, and SAM-TB, for detecting resistance in 88 Ecuadorian isolates of Mycobacterium tuberculosis drug susceptibility tested previously. Statistical analysis was used to determine the correlation between genomic and phenotypic analysis. Our results showed that with the exception of KvarQ, all tools had the highest correlation with the conventional drug susceptibility test (DST) for global resistance detection (98% agreement and 0.941 Cohen's kappa), while SAM-TB, PhyResSE, TB-profiler and Mykrobe had better correlations with DST for first-line drug analysis individually. We also identified that in our study, only 50% of mutations characterized by the web-based tools in the rpoB, katG, embB, pncA, gyrA and rrs regions were canonical and included in the World Health Organization (WHO) catalogue. Our findings suggest that SAM-TB, PhyResSE, TB-profiler and Mykrobe were efficient in determining canonical resistance-related mutations, but more analysis is needed to improve second-line detection. Improving surveillance programs using whole-genome sequencing tools for first-line drugs, MDR-TB and XDR-TB is essential to understand the molecular epidemiology of TB in Ecuador.

IMPORTANCE

Tuberculosis, an infectious disease caused by Mycobacterium tuberculosis, most commonly affects the lungs and is often spread through the air when infected people cough, sneeze, or spit. However, despite the existence of effective drug treatment, patient adherence, long duration of treatment, and late diagnosis have reduced the effectiveness of therapy and increased drug resistance. The increase in resistant cases, added to the impact of the COVID-19 pandemic, has highlighted the importance of implementing efficient and timely diagnostic methodologies worldwide. The significance of our research is in evaluating and identifying a more efficient and user-friendly web-based tool to characterize resistance in Mycobacterium tuberculosis by whole-genome sequencing, which will allow more routine application to improve TB strain surveillance programs locally.

Prolonged survival of a patient with active MDR-TB HIV co-morbidity: insights from a Mycobacterium tuberculosis strain with a unique genomic deletion

Coinfection of HIV and multidrug-resistant tuberculosis (MDR-TB) presents significant challenges in terms of the treatment and prognosis of tuberculosis, leading to complexities in managing the disease and impacting the overall outcome for TB patients. This study presents a remarkable case of a patient with MDR-TB and HIV coinfection who survived for over 8 years, despite poor treatment adherence and comorbidities. Whole genome sequencing (WGS) of the infecting Mycobacterium tuberculosis (Mtb) strain revealed a unique genomic deletion, spanning 18 genes, including key genes involved in hypoxia response, intracellular survival, immunodominant antigens, and dormancy. This deletion, that we have called "Del-X," potentially exerts a profound influence on the bacterial physiology and its virulence. Only few similar deletions were detected in other non-related Mtb genomes worldwide. In vivo evolution analysis identified drug resistance and metabolic adaptation mutations and their temporal dynamics during the patient's treatment course.

Metagenomic insight into the prevalence and driving forces of antibiotic resistance genes in the whole process of three full-scale wastewater treatment plants

The spread of antibiotic resistance genes (ARGs) is an emerging global health concern, and wastewater treatment plants (WWTPs), as an essential carrier for the occurrence and transmission of ARGs, deserves more attention. Based on the Illumina NovaSeq high-throughput sequencing platform, this study conducted a metagenomic analysis of 18 samples from three full-scale WWTPs to explore the fate of ARGs in the whole process (influent, biochemical treatment, advanced treatment, and effluent) of wastewater treatment. Total 70 ARG subtypes were detected, among which multidrug, aminoglycoside, tetracycline, and macrolide ARGs were most abundant. The different treatment processes used for three WWTPs were capable of reducing ARG diversity, but did not significantly reduce ARG abundance. Compared to that by denitrification filters, the membrane bioreactor (MBR) process was advantageous in controlling the prevalence of multidrug ARGs in WWTPs. Linear discriminant analysis Effect Size (LEfSe) suggested g_Nitrospira, g_Curvibacter, and g_Mycobacterium as the key bacteria responsible for differential ARG prevalence among different WWTPs. Meanwhile, adeF, sul1, and mtrA were the persistent antibiotic resistance genes (PARGs) and played dominant roles in the prevalence of ARGs. Proteobacteria and Actinobacteria were the host bacteria of majority ARGs in WWTPs, while Pseudomonas and Nitrospira were the most crucial host bacteria influencing the dissemination of critical ARGs (e.g., adeF). In addition, microbial richness was determined to be the decisive factor affecting the diversity and abundance of ARGs in wastewater treatment processes. Overall, regulating the abundance of microorganisms and key host bacteria by selecting processes with microbial interception, such as MBR process, may be beneficial to control the prevalence of ARGs in WWTPs.

Genetic Polymorphisms of UDP-Glucuronosyltransferases and Susceptibility to Antituberculosis Drug-Induced Liver Injury: A Systematic Review and Meta-Analysis

Methods

The PRISMA statement was strictly followed, and the protocol was registered in PROSPERO (CRD42022339317). The PICOS framework was used: patients received antituberculosis treatment, UGTs polymorphisms (mutants), UGTs polymorphisms (wild), AT-DILI, and case-control studies. Eligible studies were searched through nine databases up to April 27, 2022. The study's qualities were assessed by the revised Little's recommendations. Meta-analysis was conducted with a random-effects model using odds ratios (ORs) with 95% confidence intervals (95% CIs) as the effect size.

Results

Twelve case-control studies with 2128 cases and 4338 controls were included, and 32 single nucleotide polymorphisms (SNPs) in the seven UGT genes have been reported in Chinese and Korean. All studies were judged as high quality. The pooled results indicated that UGT1A1 rs3755319 (AC vs. AA, OR = 1.454, 95% CI: 1.100-1.921, P = 0.009), UGT2B7 rs7662029 (G vs. A, OR = 1.547, 95% CI: 1.249-1.917, P < 0.0001; GG + AG vs. AA, OR = 2.371, 95% CI: 1.779-3.160, P < 0.0001; AG vs. AA, OR = 2.686, 95% CI: 1.988-3.627, P < 0.0001), and UGT2B7 rs7439366 (C vs. T, OR = 0.585, 95% CI: 0.477-0.717, P < 0.0001; CC + TC vs. TT, OR = 0.347, 95% CI: 0.238-0.506, P < 0.0001; CC vs. TC + TT, OR = 0.675, 95% CI: 0.507-0.898, P = 0.007) might be associated with the risk of AT-DILI.

Conclusions

The polymorphisms of UGT1A1 rs3755319, UGT2B7 rs7662029, and UGT2B7 rs7439366 were significantly associated with AT-DILI susceptibility. However, this conclusion should be interpreted with caution due to the low number of studies and the relatively small sample size.

N-Pyrazinylhydroxybenzamides as biologically active compounds: a hit-expansion study and antimicrobial evaluation

Background: The development of novel antimicrobial drugs is an essential part of combatting the uprising of antimicrobial resistance. Proper hit-to-lead development is crucially needed. Methods & results: We present a hit-expansion study of N-pyrazinyl- and N-pyridyl-hydroxybenzamides with a comprehensive determination of structure-activity relationships. The antimicrobial screening revealed high selectivity to staphylococci along with antimycobacterial activity with the best value of 6.25 μg/ml against Mycobacterium tuberculosis H37Rv. We proved an inhibition of proteosynthesis and a membrane depolarization of methicillin-resistant Staphylococcus aureus. Conclusion: Our results are a good starting point for further development of new antimicrobial compounds, where the next step would be tuning the potential between relatively nonspecific membrane depolarization effect and specific inhibition of proteosynthesis.

Comorbidity and drug resistance of smear-positive pulmonary tuberculosis patients in the yi autonomous prefecture of China: a cross-sectional study

BACKGROUND

Tuberculosis (TB) has a high morbidity and mortality rate, and its prevention and treatment focus is on impoverished areas. The Liangshan Yi Autonomous Prefecture is a typical impoverished area in western China with insufficient medical resources and high HIV positivity. However, there have been few reports of TB and drug resistance in this area.

METHODS

We collected the demographic and clinical data of inpatients with sputum smear positive TB between 2015 and 2021 in an infectious disease hospital in the Liangshan Yi Autonomous Prefecture. Descriptive analyses were used for the epidemiological data. The chi-square test was used to compare categorical variables between the drug-resistant and drug-susceptible groups, and binary logistic regression was used to analyse meaningful variables.

RESULTS

We included 2263 patients, 79.9% of whom were Yi patients. The proportions of HIV (14.4%) and smoking (37.3%) were higher than previously reported. The incidence of extrapulmonary TB (28.5%) was high, and the infection site was different from that reported previously. When drug resistance gene detection was introduced, the proportion of drug-resistant patients became 10.9%. Patients aged 15-44 years (OR 1.817; 95% CI 1.162-2.840; P < 0.01) and 45-59 years (OR 2.175; 95% CI 1.335-3.543; P < 0.01) had significantly higher incidences of drug resistance than children and the elderly. Patients with a cough of ≥ 2 weeks had a significantly higher chance of drug resistance than those with < 2 weeks or no cough symptoms (OR 2.069; 95% CI 1.234-3.469; P < 0.01). Alcoholism (OR 1.741; 95% CI 1.107-2.736; P < 0.05) and high bacterial counts on sputum acid-fast smears (OR 1.846; 95% CI 1.115-3.058; P < 0.05) were significant in the univariate analysis.

CONCLUSIONS

Sputum smear-positive TB predominated in Yi men (15-44 years) with high smoking, alcoholism, and HIV rates. Extrapulmonary TB, especially abdominal TB, prevailed. Recent drug resistance testing revealed higher rates in 15-59 age group and ≥ 2 weeks cough duration. Alcohol abuse and high sputum AFB counts correlated with drug resistance. Strengthen screening and supervision to curb TB transmission and drug-resistant cases in the region.

Wollamide Cyclic Hexapeptides Synergize with Established and New Tuberculosis Antibiotics in Targeting Mycobacterium tuberculosis

Shorter and more effective treatment regimens as well as new drugs are urgent priorities for reducing the immense global burden of tuberculosis (TB). As treatment of TB currently requires multiple antibiotics with diverse mechanisms of action, any new drug lead requires assessment of potential interactions with existing TB antibiotics. We previously described the discovery of wollamides, a new class of Streptomyces-derived cyclic hexapeptides with antimycobacterial activity. To further assess the value of the wollamide pharmacophore as an antimycobacterial lead, we determined wollamide interactions with first- and second-line TB antibiotics by determining fractional inhibitory combination index and zero interaction potency scores. In vitro two-way and multiway interaction analyses revealed that wollamide B1 synergizes with ethambutol, pretomanid, delamanid, and para-aminosalicylic acid in inhibiting the replication and promoting the killing of phylogenetically diverse clinical and reference strains of the Mycobacterium tuberculosis complex (MTBC). Wollamide B1 antimycobacterial activity was not compromised in multi- and extensively drug-resistant MTBC strains. Moreover, growth-inhibitory antimycobacterial activity of the combination of bedaquiline/pretomanid/linezolid was further enhanced by wollamide B1, and wollamide B1 did not compromise the antimycobacterial activity of the isoniazid/rifampicin/ethambutol combination. Collectively, these findings add new dimensions to the desirable characteristics of the wollamide pharmacophore as an antimycobacterial lead compound. IMPORTANCE Tuberculosis (TB) is an infectious disease that affects millions of people globally, with 1.6 million deaths annually. TB treatment requires combinations of multiple different antibiotics for many months, and toxic side effects can occur. Therefore, shorter, safer, more effective TB therapies are required, and these should ideally also be effective against drug-resistant strains of the bacteria that cause TB. This study shows that wollamide B1, a chemically optimized member of a new class of antibacterial compounds, inhibits the growth of drug-sensitive as well as multidrug-resistant Mycobacterium tuberculosis isolated from TB patients. In combination with TB antibiotics, wollamide B1 synergistically enhances the activity of several antibiotics, including complex drug combinations that are currently used for TB treatment. These new insights expand the catalogue of the desirable characteristics of wollamide B1 as an antimycobacterial lead compound that might inspire the development of improved TB treatments.

Niosome as an Effective Nanoscale Solution for the Treatment of Microbial Infections

Numerous disorders go untreated owing to a lack of a suitable drug delivery technology or an appropriate therapeutic moiety, particularly when toxicities and side effects are a major concern. Treatment options for microbiological infections are not fulfilled owing to significant adverse effects or extended therapeutic options. Advanced therapy options, such as active targeting, may be preferable to traditional ways of treating infectious diseases. Niosomes can be defined as microscopic lamellar molecules formed by a mixture of cholesterol, nonionic surfactants (alkyl or dialkyl polyglycerol ethers), and sometimes charge-inducing agents. These molecules comprise both hydrophilic and hydrophobic moieties of varying solubilities. In this review, several pathogenic microbes such as Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Plasmodium, Leishmania, and Candida spp. have been evaluated. Also, the development of a proper niosomal formulation for the required application was discussed. This review also reviews that an optimal formulation is dependent on several aspects, including the choice of nonionic surfactant, fabrication process, and fabrication parameters. Finally, this review will give information on the effectiveness of niosomes in treating acute microbial infections, the mechanism of action of niosomes in combating microbial pathogens, and the advantages of using niosomes over other treatment modalities.

DprE1 Inhibitors: Enduring Aspirations for Future Antituberculosis Drug Discovery

DprE1 is a crucial enzyme involved in the cell wall synthesis of Mycobacterium tuberculosis and a promising target for antituberculosis drug development. However, its unique structural characteristics for ligand binding and association with DprE2 make developing new clinical compounds challenging. This review provides an in-depth analysis of the structural requirements for both covalent and non-covalent inhibitors, their 2D and 3D binding patterns, as well as their biological activity data in vitro and in vivo, including pharmacokinetic information. We also introduce a protein quality score (PQS) and an active-site map of the DprE1 enzyme to help medicinal chemists better understand DprE1 inhibition and develop new and effective anti-TB drugs. Furthermore, we examine the resistance mechanisms associated with DprE1 inhibitors to understand future developments due to resistance emergence. This comprehensive review offers insight into the DprE1 active site, including protein-binding maps, PQS, and graphical representations of known inhibitors, making it a valuable resource for medicinal chemists working on future antitubercular compounds.

The Use of Particulate Systems for Tuberculosis Prophylaxis and Treatment: Opportunities and Challenges

The use of particles to develop vaccines and treatments for a wide variety of diseases has increased, and their success has been demonstrated in preclinical investigations. Accurately targeting cells and minimizing doses and adverse side effects, while inducing an adequate biological response, are important advantages that particulate systems offer. The most used particulate systems are liposomes and their derivatives, immunostimulatory complexes, virus-like particles, and organic or inorganic nano- and microparticles. Most of these systems have been proven using therapeutic or prophylactic approaches to control tuberculosis, one of the most important infectious diseases worldwide. This article reviews the progress and current state of the use of particles for the administration of TB vaccines and treatments in vitro and in vivo, with a special emphasis on polymeric particles. In addition, we discuss the challenges and benefits of using these particulate systems to provide researchers with an overview of the most promising strategies in current preclinical trials, offering a perspective on their progress to clinical trials.

Tuberculosis and Sudden Death in Lithuania

Background

Tuberculosis is one of the most common infectious diseases in the world. 10.6 million people fell ill in 2021 and 1.6 million died from the disease. Lithuania has the third-highest tuberculosis incidence rate per 100,000 and the second-highest mortality rate per 100,000 in EU/EEA countries. During 2015-2021 years, there were 799 deaths of pulmonary tuberculosis in Lithuania. However, the presence of pulmonary tuberculosis is often unknown before death and is only revealed during autopsy. The aim of the study is to review current literature on this topic and present statistical analysis on evaluated socioeconomical, epidemiological indicators, as well as autopsy findings that may suggest pulmonary tuberculosis infection.

Materials and methods

This research was designed as a retrospective study focusing on full forensic pathology autopsies between 2015 and 2021. Of these, 100 cases were randomly selected where the cause of death was tuberculosis diagnosed during post-mortem examination and compared to a control group consisting of 415 cases of sudden death.

Results

The study revealed that out of 100 pulmonary tuberculosis cases, 90% were male with the mean age of 53.48 ± 11.12 years old. In the case of sudden death where tuberculosis was found, a significant portion of the sample (91%) was not followed up at any medical institution. Regarding socioeconomic factors, a moderate negative correlation between Lithuania's gross domestic product and tuberculosis distribution was observed, as well as a weak negative correlation between alcohol consumption (l per capita) in the general population and tuberculosis distribution. The lung weight of the pulmonary tuberculosis group was statistically significantly higher than that of the control group.

Conclusions

Tuberculosis remains a major problem in Lithuania and the combination of socioeconomic indicators determines the prevalence of tuberculosis in the country. In cases of sudden death, autopsy helps to identify tuberculosis cases that have not been clinically detected and ensures tuberculosis monitoring. Therefore, the person who performs autopsy remains at high risk of contracting tuberculosis. Furthermore, extreme caution is advised if higher lung weight or hardenings are seen during autopsy because of the possibility of tuberculosis.

Synthesis and pharmacological evaluation of 1,3-diaryl substituted pyrazole based (thio)urea derivatives as potent antimicrobial agents against multi-drug resistant Staphylococcus aureus and Mycobacterium tuberculosis

The urgent development of newer alternatives has been deemed a panacea for tackling emerging antimicrobial resistance effectively. Herein, we report the design, synthesis, and biological evaluation of 1,3-diaryl substituted pyrazole-based urea and thiourea derivatives as antimicrobial agents. Preliminary screening results revealed that compound 7a (3,4-dichlorophenyl derivative) exhibited potent activity against S. aureus (MIC = 0.25 μg mL-1) and compound 7j (2,4-difluorophenyl derivative) against Mycobacterium tuberculosis (MIC = 1 μg mL-1). Compounds 7a and 7j were non-toxic to Vero cells with a favorable selectivity index of 40 and 200, respectively, and demonstrated good microsomal stability. Compound 7a exhibited equipotent activity (MIC = 0.25 μg mL-1) against various multidrug-resistant strains of S. aureus, which include various strains of MRSA and VRSA, and elicited bacteriostatic properties. In an enzymatic assay, 7a effectively inhibited DNA gyrase supercoiling activity at a concentration of 8 times MIC. Further, molecular modeling studies suggested that compound 7a binds at the active site of DNA gyrase with good affinity.

New advances in the treatments of drug-resistant tuberculosis

INTRODUCTION

TB is associated with high mortality and morbidity among infected individuals and a high transmission rate from person to person. Despite the availability of vaccines and several anti-TB,TB infection continues to increase. Global resistance to TB remains the greatest challenge. There has not been extensive research into a new treatment and management strategy for TB resistance therapy. This review is based on a review of new advances and alternative drugs in the treatment of drug-resistant TB.

AREAS COVERED

New drug-resistant Mycobacterium tuberculosis therapy involves a combination of the latest TB drugs, new anti-TB drugs based on medicinal plant extracts for drug-resistant TB, mycobacteriophage therapy, the CRISPR/Cas9 system, and nanotechnology.

EXPERT OPINION

It is necessary to determine the function of individual gene alterations in drug-resistant TB. A combination of the most recent anti-TB drugs, such as bedaquiline and delamanid, is recommended. Longitudinal studies and animal model experiments with some medicinal plant extracts are required for better results. Nanotechnology has the potential to reduce drug side effects. Useful efficacy of phage therapy and CRISPR-cas9 technology as adjunct therapies for the management of drug-resistant TB.