Accelerating development of new shorter TB treatment regimens in anticipation of a resurgence of multi-drug resistant TB due to the COVID-19 pandemic

Key challenges in TB drug discovery: A perspective

Over the past 2000 years, tuberculosis (TB) has been responsible for more deaths than any other infectious disease. In recent years, there has been a recovery of research and development (R&D) efforts focused on TB drugs. This is driven by the pressing need to combat the global spread of the disease and develop improved therapies for both drug-sensitive and drug-resistant strains. Many new TB drug candidates have recently entered clinical trials, marking the beginning of a rebirth in this area after decades of neglect. The problem is that very few of the hundreds of compounds identified each year as potential anti-TB drugs really make it to the clinical development stage. This perspective focuses on the primary obstacles and approaches involved in the development of new medications for TB. This will help medicinal chemists better understand TB drug challenges and develop novel drug candidates.

The global impact of COVID-19 on tuberculosis: A thematic scoping review, 2020-2023

BACKGROUND

This thematic scoping review of publications sought to understand the global impact of COVID-19 on tuberculosis (TB), interpret the scope of resonating themes, and offer policy recommendations to stimulate TB recovery and future pandemic preparedness.

DATA SOURCES

Publications were captured from three search engines, PubMed, EBSCO, and Google Scholar, and applicable websites written in English from January 1, 2020, to April 30, 2023.

STUDY SELECTION

Our scoping review was limited to publications detailing the impact of COVID-19 on TB. Original research, reviews, letters, and editorials describing the deleterious and harmful--yet sometimes positive--impact of COVID-19 (sole exposure) on TB (sole outcome) were included. The objective was to methodically categorize the impacts into themes through a comprehensive review of selected studies to provide significant health policy guidance.

DATA EXTRACTION

Two authors independently screened citations and full texts, while the third arbitrated when consensus was not met. All three performed data extraction.

DATA SYNTHESIS/RESULTS

Of 1,755 screened publications, 176 (10%) covering 39 countries over 41 months met the inclusion criteria. By independently using a data extraction instrument, the three authors identified ten principal themes from each publication. These themes were later finalized through a consensus decision. The themes encompassed TB's care cascade, patient-centered care, psychosocial issues, and health services: 1) case-finding and notification (n = 45; 26%); 2) diagnosis and laboratory systems (n = 19; 10.7%) 3) prevention, treatment, and care (n = 22; 12.2%); 4) telemedicine/telehealth (n = 12; 6.8%); 5) social determinants of health (n = 14; 8%); 6) airborne infection prevention and control (n = 8; 4.6%); 7) health system strengthening (n = 22; 13%); 8) mental health (n = 13; 7.4%); 9) stigma (n = 11; 6.3%); and 10) health education (n = 10; 5.7%).

LIMITATIONS

Heterogeneity of publications within themes.

CONCLUSIONS

We identified ten globally generalizable themes of COVID-19's impact on TB. The impact and lessons learned from the themed analysis propelled us to draft public health policy recommendations to direct evidence-informed guidance that strengthens comprehensive global responses, recovery for TB, and future airborne pandemic preparedness.

Factors associated with tuberculosis treatment outcomes among TB patients aged 15 years and older at chawama level one hospital in Lusaka, Zambia

Tuberculosis is a global health concern n impacting communities, health systems, and economies This study assessed the TB treatment outcomes among individuals aged 15+ at Chawama first level hospital in Lusaka, Zambia, using a retrospective design focussing on individuals notified in 2020. The sample was described using descriptive statistics. The Pearson Chi-square test and logistics regression were used to analyse the characteristics of the patients influencing the treatment outcomes at 5% significant level. Out of 404 participants, 83.4% of them had successful treatment outcomes. Varied outcomes were noted in sex, patient type, TB type, HIV status, and DOT plan, but lacked significance. Odds of success were lower by 72.4% for those aged 65+ compared to those aged 15-24 years (OR (95% CI): 0.276 (0.086-0.881), p = .030). Similarly, after adjusting for other variables, the odds of success were lower by 72.9% (AOR (95% CI): 0.271 (0.083-0.882), p = .030). This study yielded an encouraging 83.4% TB success rate highlighting the potential for improvement to meet WHO targets. Notably, individuals aged 65+ showed a distinct pattern with lower treatment success odds, suggesting a need for focussed interventions. Special attention to elderly patients and targeted TB program interventions are recommended.

Drug-Resistant Tuberculosis and COVID-19: A Scoping Review on a New Threat to Antimicrobial Resistance

OBJECTIVE

To assess the impact of COVID-19 on the morbidity and mortality associated with drug-resistant tuberculosis (DR-TB).

METHODS

A comprehensive review of articles published in international databases since December 2019 was conducted. The findings are presented in a narrative format, supplemented with tables, diagrams, and a map created using ArcGIS software.

RESULTS

Thirty-five studies were selected, highlighting the significant consequences of COVID-19 on TB and DR-TB treatment progress. Four main thematic areas were identified: Clinical and epidemiological aspects of the interaction between COVID-19 and DR-TB; Management of physical resources and the team; Challenges and circumstances; Perspectives and possibilities.

CONCLUSIONS

This study revealed that the COVID-19 pandemic significantly negatively impacted the control of long-standing diseases like TB, particularly in the context of morbidity and mortality related to DR-TB.

Synthesis, characterization, in vitro antimycobacterial and cytotoxicity evaluation, DFT calculations, molecular docking and ADME studies of new isomeric benzimidazole-1,2,3-triazole-quinoline hybrid mixtures

New benzimidazole-1,2,3-triazole-quinoline hybrids and their intermediates, differing in substitutions at the C-2 and/or C6 positions of the benzimidazole ring, were successfully synthesized in 55---80 % yields, with the C6-substituted ones forming as inseparable tautomeric mixtures. The synthesized compounds were fully characterised by FT-IR, 1D- and 2D-NMR, and HRMS. In-depth NMR analysis and DFT molecular calculations showed that the tautomeric mixtures formed in a ratio of almost 1:1 ratio (cis and trans), except for 5 g, where the ratio is 1:2. In vitro antimycobacterial activity evaluation against the H37Rv strain of Mycobacterial tuberculosis was undertaken on all synthesized compounds, and a selected number were further screened for their cytotoxicity on TZM-bl cell lines. Hybrid compounds showed excellent MIC90 activities ranging from 1.07 to 8.66 μM and were all more efficacious than the first-line reference drug, ethambutol (MIC90 = 9.54 μM). In particular, hybrid compounds 5b (MIC90 = 1.54 μM, CC50 = 58.89 μM and % cell viability = 14.07), 5d (MIC90 = 2.08 μM, CC50 = 0.27 μM, and % cell viability = 149.50 %) and 5 g (MIC90 = 1.49 μM, CC50 = 4.62 μM and % cell viability = 44.03) were the most promising. Significantly, 5b and 5 g were over six times more efficacious than ethambutol but exhibited cytotoxicity towards TZM-bl cell-lines compared to 5d, which was over four times more active than ethambutol. The physical combination (mimicking combination therapy) of individual pharmacophoric components making up 5 g were less active, indicating the synergistic effect of hybridization. In addition, more than 60 % of all the synthesized hybrids showed better activity than their respective pharmacophoric components. In silico ADME studies of the hybrids revealed favourable physico-chemical properties, while molecular modeling studies suggested binding interactions with Val 61, Gly 62, Glu 65, Ala 66, and Phe 69 amino acid in a reported similar manner to bedaquiline, an approved quinoline-based anti-TB drug.

A study of analysis on prevalence, serological marker and prognosis of tuberculosis in tertiary care hospital

BACKGROUND

Tuberculosis is an infectious disease responsible for a significant cause of ill health. According to the WHO global tuberculosis report 2021. 9.9 million cases fell sick with TB in 2020. Significantly, the prevalence of tuberculosis in India is 25%.

OBJECTIVE

To analyze the prevalence of tuberculosis in the suburban areas of the metropolitan city in South India. To analyze the serological marker and prognosis of tuberculosis among males and females. To determine the importance of molecular testing - PCR confirmation on TB after AFB smear.

METHODS

A retrospective study to analyze 462 patients enrolled by the respiratory medicine department on suspecting pulmonary- 356 (M-264 & F-92) and extra-pulmonary-106 (M-73&F-33) patients and diagnosed Zhiel-Neelsen staining, Mantoux test, Chip-based RT-PCR test, Erythrocyte sedimentation rate, and analyzed serological test such as C-Reactive Protein, Chemiluminescence immune assay.

RESULTS

23 patients were positive in Ziehl-Neelsen staining, 65 were positive in molecular True-Nat PCR test, Mantoux skin test induration in 10 patients, 98 TB Positive patients examined in the serological analysis, 1 & 3 patients reacted in HIV/HBsAg, and HBsAg test respectively, by chemiluminescence immunoassay, 8 PTB and 4 EPTB and 47 non-TB patients were positive in C-reactive protein, 46 TB and 94 non-TB patients detected abnormal values out of these 160 patients in ESR test.

CONCLUSION

The Prevalence of tuberculosis is significantly rising, especially in the middle-aged population. The rapid molecular diagnostics to detect TB are highly sensitive and specific. Serological markers are essential for the analysis of disease prognosis and need to focus on the guidance of DOTS and RNTCP to End TB.

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.

Predictors of mortality among drug-resistant tuberculosis patients in Kaduna State, Nigeria

Background

Specific death due to DR-TB has significantly contributed to tuberculosis (TB) mortality and overall global deaths.

Aim

This study examines the predictors of mortality among DR-TB patients in Kaduna State, Nigeria.

Subject and Method

This was a retrospective longitudinal study of DR-TB mortality carried out among 370 DR-TB patients from the 23 LGAs in Kaduna State. It involves a retrospective review of the MDR-TB records of the patients over a period of 10 years (2012-2021). Demographic and clinical data of all DR-TB patients enrolled in Kaduna State, Nigeria, between April 1, 2012, and March 31, 2021, were used. Survival analysis was performed with SPSS version 25, using Kaplan-Meier and Cox proportional hazard regression modeling, at 5% significance level.

Results

The majority of the patients, 255 (68.9%), were below the age of 40 years, while 53 (14.3%) of the patients died within the study period. Most deaths 26 (49.1%) were associated with HIV co-infection and the disease severity. Results for the Cox proportional model show that there was a significantly lower risk of death when a patient had MDR-TB compared to pre-XDR-TB (adjusted hazard ratio, AHR = 0.34, 95% CI = 0.16-0.72, P = 0.04). Both models show that age, sex, residence, or year of treatment had no significant association with survival or death.

Conclusion

HIV co-infection and DRTB with progression to more resistant and difficult-to-treat strains contributed to higher deaths. There is a need for concerted efforts from all DR-TB stakeholders to control the disease.

Hydrazone-Tethered 5-(Pyridin-4-yl)-4H-1,2,4-triazole-3-thiol Hybrids: Synthesis, Characterisation, in silico ADME Studies, and in vitro Antimycobacterial Evaluation and Cytotoxicity

Compounds containing arylpyrrole-, 1,2,4-triazole- and hydrazone structural frameworks have been widely studied and demonstrated to exhibit a wide range of pharmacological properties. Herein, an exploratory series of new 1,2,4-triazole derivatives designed by amalgamation of arylpyrrole and 1,2,4-triazole structural units via a hydrazone linkage is reported. The synthesised compounds were tested in vitro for their potential activity against Mycobacterium tuberculosis (MTB) H₃₇ Rv strain. The most promising compound 13 - the derivative without the benzene ring appended to the pyrrole unit displayed acceptable activity (MIC₉₀ =3.99 μM) against MTB H₃₇ Rv, while other compounds from the series exhibited modest to weak antimycobacterial activity with MIC₉₀ values in the range between 7.0 and >125 μM. Furthermore, in silico results, predicated using the SwissADME web tool, show that the prepared compounds display desirable ADME profile with parameters within acceptable range.

Treatment Results of Multidrug-Resistant Tuberculosis Patients in the Aegean Region

OBJECTIVE

We aimed to evaluate 109 rifampicin-resistant or multidrug-resistant tuberculosis patients who are treated in Izmir Chest Diseases MDR Tuberculosis Centre.

MATERIAL AND METHODS

The patient profile, side effects, treatment success, and mortality of rifampicin-resistant or multidrugresistant tuberculosis patients who were followed up and treated in our hospital's tuberculosis service between 2010 and 2018 were analyzed retrospectively.

RESULTS

Of the rifampicin-resistant or multidrug-resistant tuberculosis patients, 83 (76.1%) were male and the mean age was 46.3 ± 16.3 years. Of the cases 13 (11.9%) had rifampicin resistance without isoniazid. Since 5 out of 109 patients diagnosed with multidrugresistant tuberculosis emigrated to other countries, the treatment results of 104 patients were evaluated. As a result of the treatment, the cure was achieved in 81 (77.9%) patients and treatment was completed in 13 (12.5%). Treatment success was found as 90.4%. No patient experienced recurrence. The mortality rate was determined as 9.6%. The cure rate of patients treated with ≥6 drugs (90.9%) was statistically significantly (P = .029) higher than the group treated with ≤5 drugs (71.8%).

CONCLUSIONS

Multidrug-resistant tuberculosis treatment is a long-term, financially burdensome practice that may cause serious side effects and complications, and it requires strict discipline. The fight against tuberculosis can be successful with tuberculosis control programs that are pursued with determination.

Study of the Rv1417 and Rv2617c Membrane Proteins and Their Interactions with Nicotine Derivatives as Potential Inhibitors of Erp Virulence-Associated Factor in Mycobacterium tuberculosis: An In Silico Approach

The increasing emergence of Mycobacterium tuberculosis (Mtb) strains resistant to traditional anti-tuberculosis drugs has alarmed health services worldwide. The search for new therapeutic targets and effective drugs that counteract the virulence and multiplication of Mtb represents a challenge for the scientific community. Several studies have considered the erp gene a possible therapeutic target in the last two decades, since its disruption negatively impacts Mtb multiplication. This gene encodes the exported repetitive protein (Erp), which is located in the cell wall of Mtb. In vitro studies have shown that the Erp protein interacts with two putative membrane proteins, Rv1417 and Rv2617c, and the impairment of their interactions can decrease Mtb replication. In this study, we present five nicotine analogs that can inhibit the formation of heterodimers and trimers between these proteins. Through DFT calculations, molecular dynamics, docking, and other advanced in silico techniques, we have analyzed the molecular complexes, and show the effect these compounds have on protein interactions. The results show that four of these analogs can be possible candidates to counteract the pathogenicity of Mtb. This study aims to combine research on the Erp protein as a therapeutic target in the search for new drugs that serve to create new therapies against tuberculosis disease.

A New Benzothiazolthiazolidine Derivative, 11726172, Is Active In Vitro, In Vivo, and against Nonreplicating Cells of Mycobacterium tuberculosis

Tuberculosis (TB) still poses a global menace as one of the deadliest infectious diseases. A quarter of the human population is indeed latently infected with Mycobacterium tuberculosis. People with latent infection have a 5 to 10% lifetime risk of becoming ill with TB, representing a reservoir for TB active infection. This is a worrisome problem to overcome in the case of relapse; unfortunately, few drugs are effective against nonreplicating M. tuberculosis cells. Novel strategies to combat TB, including its latent form, are urgently needed. In response to the lack of new effective drugs and after screening about 500 original chemical molecules, we selected a compound, 11726172, that is endowed with potent antitubercular activity against M. tuberculosis both in vitro and in vivo and importantly also against dormant nonculturable bacilli. We also investigated the mechanism of action of 11726172 by applying a multidisciplinary approach, including transcriptomic, labeled metabolomic, biochemical, and microbiological procedures. Our results represent an important step forward in the development of a new antitubercular compound with a novel mechanism of action active against latent bacilli. IMPORTANCE The discontinuation of TB services due to COVID-19 causes concern about a future resurgence of TB, also considering that latent infection affects a high number of people worldwide. To combat this situation, the identification of antitubercular compounds targeting Mycobacterium tuberculosis through novel mechanisms of action is necessary. These compounds should be active against not only replicating bacteria cells but also nonreplicating cells to limit the reservoir of latently infected people on which the bacterium can rely to spread after reactivation.

A Hydrazine-Hydrazone Adamantine Compound Shows Antimycobacterial Activity and Is a Probable Inhibitor of MmpL3

Tuberculosis remains an important cause of morbidity and mortality throughout the world. Notably, an important number of multi drug resistant cases is an increasing concern. This problem points to an urgent need for novel compounds with antimycobacterial properties and to improve existing therapies. Whole-cell-based screening for compounds with activity against Mycobacterium tuberculosis complex strains in the presence of linezolid was performed in this study. A set of 15 bioactive compounds with antimycobacterial activity in vitro were identified with a minimal inhibitory concentration of less than 2 µg/mL. Among them, compound 1 is a small molecule with a chemical structure consisting of an adamantane moiety and a hydrazide–hydrazone moiety. Whole genome sequencing of spontaneous mutants resistant to the compounds suggested compound 1 to be a new inhibitor of MmpL3. This compound binds to the same pocket as other already published MmpL3 inhibitors, without disturbing the proton motive force of M. bovis BCG and M. smegmatis. Compound 1 showed a strong activity against a panel ofclinical strains of M. tuberculosis in vitro. This compound showed no toxicity against mammalian cells and protected Galleria mellonella larvae against M. bovis BCG infection. These results suggest that compound 1 is a promising anti-TB agent with the potential to improve TB treatment in combination with standard TB therapies.

Bottlenecks and opportunities in antibiotic discovery against Mycobacterium tuberculosis

Tuberculosis (TB) persists as a major global health issue and a leading cause of death by a single infectious agent. The global burden of TB is further exacerbated by the continuing emergence and dissemination of strains of Mycobacterium tuberculosis resistant to multiple antibiotics. The need for novel drugs that can be used to shorten the course for current TB drug regimens as well as combat the persistent threat of antibiotic resistance has never been greater. There have been significant advances in the discovery of de novo TB treatments, with the first TB-specific drugs in 45 years approved for use. However, there are still issues that restrict the pipeline of new antitubercular chemotherapies. The rate of failure of TB drug candidates in clinical trials remains high, while the validation of new TB drug targets and subsequent identification of novel inhibitors remains modest.

Tuberculosis Drug Discovery: Challenges and New Horizons

Over the past 2000 years, tuberculosis (TB) has claimed more lives than any other infectious disease. In 2020 alone, TB was responsible for 1.5 million deaths worldwide, comparable to the 1.8 million deaths caused by COVID-19. The World Health Organization has stated that new TB drugs must be developed to end this pandemic. After decades of neglect in this field, a renaissance era of TB drug discovery has arrived, in which many novel candidates have entered clinical trials. However, while hundreds of molecules are reported annually as promising anti-TB agents, very few successfully progress to clinical development. In this Perspective, we critically review those anti-TB compounds published in the last 6 years that demonstrate good in vivo efficacy against Mycobacterium tuberculosis. Additionally, we highlight the main challenges and strategies for developing new TB drugs and the current global pipeline of drug candidates in clinical studies to foment fresh research perspectives.

Comparison of Disability-Adjusted Life Years (DALYs) and Economic Burden on People With Drug-Susceptible Tuberculosis and Multidrug-Resistant Tuberculosis in Korea

In the future, tuberculosis (TB) will place a heavy burden on the aging population in Korea. To prepare for this crisis, it is important to analyze the disease burden trend of drug-susceptible tuberculosis (DS-TB) and multidrug-resistant tuberculosis (MDR-TB). Measuring disability-adjusted life years (DALYs) and economic burden on MDR-TB patients can help reduce the incidence of TB. Accordingly, in this study, we measured the DALYs and economic burden on DS-TB and MDR-TB patients in 2014-2017 using a combination of National Health Insurance claims data, Annual Report on the Notified TB data, and Statistics Korea's mortality data. The incidence-based DALY approach implemented involved the summation of years of life lost and years lived with disability. For measuring economic burden, direct and indirect costs incurred by patients were totaled. From 2014 to 2017, DALYs per 100,000 people with DS-TB were 56, 49, 46, and 40, respectively, and DALYs per 100,000 people with MDR-TB were 3, 2, 2, and 2, respectively. The economic burden for the DS-TB population from 2014 to 2017 was $143.89 million, $136.36 million, $122.85 million, and $116.62 million, respectively, while that for MDR-TB was $413.44 million, $380.25 million, $376.46 million and $408.14 million, respectively. The results showed a decreasing trend in DALYs and economic burden for DS-TB, whereas MDR-TB was still found to be burdensome without a specific trend. With respect to age, the economic burden for both DS-TB and MDR-TB was higher among men than among women till ≤ 79 years. Conversely, the economic burden for women aged ≥80 years was higher as compared to their male counterparts. In conclusion, the incidence and spread of TB in all areas of society must be suppressed through intensive management of MDR-TB in the older population. We hope that the national TB management project will proceed efficiently when the infectious disease management system is biased to one side due to the COVID-19 pandemic.

Culture-Free Enumeration of Mycobacterium tuberculosis in Mouse Tissues Using the Molecular Bacterial Load Assay for Preclinical Drug Development

Background: The turnaround times for phenotypic tests used to monitor the bacterial load of Mycobacterium tuberculosis, in both clinical and preclinical studies, are delayed by the organism’s slow growth in culture media. The existence of differentially culturable populations of M.tuberculosis may result in an underestimate of the true number. Moreover, culture methods are susceptible to contamination resulting in loss of critical data points. Objectives: We report the adaptation of our robust, culture-free assay utilising 16S ribosomal RNA, developed for sputum, to enumerate the number of bacteria present in animal tissues as a tool to improve the read-outs in preclinical drug efficacy studies. Methods: Initial assay adaptation was performed using naïve mouse lungs spiked with known quantities of M. tuberculosis and an internal RNA control. Tissues were homogenised, total RNA extracted, and enumeration performed using RT-qPCR. We then evaluated the utility of the assay, in comparison to bacterial counts estimated using growth assays on solid and liquid media, to accurately inform bacterial load in tissues from M. tuberculosis-infected mice before and during treatment with a panel of drug combinations. Results: When tested on lung tissues derived from infected mice, the MBL assay produced comparable results to the bacterial counts in solid culture (colony forming units: CFU). Notably, under specific drug treatments, the MBL assay was able to detect a significantly higher number of M. tuberculosis compared to CFU, likely indicating the presence of bacteria that were unable to produce colonies in solid-based culture. Additionally, growth recovery in liquid media using the most probable number (MPN) assay was able to account for the discrepancy between the MBL assay and CFU number, suggesting that the MBL assay detects differentially culturable sub-populations of M. tuberculosis. Conclusions: The MBL assay can enumerate the bacterial load in animal tissues in real time without the need to wait for extended periods for cultures to grow. The readout correlates well with CFUs. Importantly, we have shown that the MBL is able to measure specific populations of bacteria not cultured on solid agar. The adaptation of this assay for preclinical studies has the potential to decrease the readout time of data acquisition from animal experiments and could represent a valuable tool for tuberculosis drug discovery and development.

Host- and Age-Dependent Transcriptional Changes in Mycobacterium tuberculosis Cell Envelope Biosynthesis Genes after Exposure to Human Alveolar Lining Fluid

Tuberculosis (TB) infection, caused by the airborne pathogen Mycobacterium tuberculosis (M.tb), resulted in almost 1.4 million deaths in 2019, and the number of deaths is predicted to increase by 20% over the next 5 years due to the COVID-19 pandemic. Upon reaching the alveolar space, M.tb comes into close contact with the lung mucosa before and after its encounter with host alveolar compartment cells. Our previous studies show that homeostatic, innate soluble components of the alveolar lining fluid (ALF) can quickly alter the cell envelope surface of M.tb upon contact, defining subsequent M.tb-host cell interactions and infection outcomes in vitro and in vivo. We also demonstrated that ALF from 60+ year old elders (E-ALF) vs. healthy 18- to 45-year-old adults (A-ALF) is dysfunctional, with loss of homeostatic capacity and impaired innate soluble responses linked to high local oxidative stress. In this study, a targeted transcriptional assay shows that M.tb exposure to human ALF alters the expression of its cell envelope genes. Specifically, our results indicate that A-ALF-exposed M.tb upregulates cell envelope genes associated with lipid, carbohydrate, and amino acid metabolism, as well as genes associated with redox homeostasis and transcriptional regulators. Conversely, M.tb exposure to E-ALF shows a lesser transcriptional response, with most of the M.tb genes unchanged or downregulated. Overall, this study indicates that M.tb responds and adapts to the lung alveolar environment upon contact, and that the host ALF status, determined by factors such as age, might play an important role in determining infection outcome.

Drug Discovery for Mycobacterium tuberculosis Using Structure-Based Computer-Aided Drug Design Approach

Developing new, more effective antibiotics against resistant Mycobacterium tuberculosis that inhibit its essential proteins is an appealing strategy for combating the global tuberculosis (TB) epidemic. Finding a compound that can target a particular cavity in a protein and interrupt its enzymatic activity is the crucial objective of drug design and discovery. Such a compound is then subjected to different tests, including clinical trials, to study its effectiveness against the pathogen in the host. In recent times, new techniques, which involve computational and analytical methods, enhanced the chances of drug development, as opposed to traditional drug design methods, which are laborious and time-consuming. The computational techniques in drug design have been improved with a new generation of software used to develop and optimize active compounds that can be used in future chemotherapeutic development to combat global tuberculosis resistance. This review provides an overview of the evolution of tuberculosis resistance, existing drug management, and the design of new anti-tuberculosis drugs developed based on the contributions of computational techniques. Also, we show an appraisal of available software and databases on computational drug design with an insight into the application of this software and databases in the development of anti-tubercular drugs. The review features a perspective involving machine learning, artificial intelligence, quantum computing, and CRISPR combination with available computational techniques as a prospective pathway to design new anti-tubercular drugs to combat resistant tuberculosis.

Adverse effects induced by second-line antituberculosis drugs: an update based on last WHO treatment recommendations for drug-resistant tuberculosis

Introduction: Tuberculosis (TB), a common condition worldwide, is still among the main infectious diseases with high mortality rates, both in adults and infants. Drug-resistant tuberculosis (DR-TB) drugs, revised by the World Health Organization (WHO) in 2018, are a prolonged and complex therapy associated with many adverse drug effects (ADEs).

Aim: To systematically review the ADEs of second-line anti-TB drugs reported in multicentric studies published after the latest WHO guidelines, compared with those from clinical trials published before 2018.

Material and methods: A PubMed search, using keywords (TB OR DR-TB) AND (adverse effects) AND “second-line anti-TB drugs”, resulted in 56 studies. Only two studies, published after the last update of WHO guidelines in 2018, reported ADEs.

Results: A total of 223 participants were included in the two selected studies. The use of multidrug regimens has been associated with an increased incidence of ADEs: 42 ADEs were recorded in 30 patients (26.3%) in the first study, while all patients had at least one ADE that occurred or worsened during treatment; and 19 (17%) had severe ADEs in the second study. However, both studies had a good favourable outcome rate (90% and 79.8%, respectively). Gastrointestinal disturbances, hepatotoxicity, headache and dizziness are the most common ADEs induced by a majority of second-line DR-TB treatments. A special attention should be given in the case of association of drugs determining QT interval (QT) prolongation on electrocardiogram, or psychiatric disorders.

Conclusions: Proper strategies about ADE management have to be planned for timely detection of the possible ADEs that can be induced by second-line anti-TB therapy.

Host- and age-dependent transcriptional changes in Mycobacterium tuberculosis cell envelope biosynthesis genes after exposure to human alveolar lining fluid

Tuberculosis (TB) infection, caused by the airborne pathogen Mycobacterium tuberculosis ( M . tb ), resulted in almost 1.4 million deaths in 2019 and the number of deaths is predicted to increase by 20% over the next 5 years due to the COVID-19 pandemic. Upon reaching the alveolar space, M . tb comes in close contact with the lung mucosa before and after its encounter with host alveolar compartment cells. Our previous studies show that homeostatic innate soluble components of the alveolar lining fluid (ALF) can quickly alter the cell envelope surface of M . tb upon contact, defining subsequent M . tb -host cell interactions and infection outcomes in vitro and in vivo . We also demonstrated that ALF from 60+ year old elders (E-ALF) vs . healthy 18- to 45-year-old adults (A-ALF) is dysfunctional with loss of homeostatic capacity and impaired innate soluble responses linked to high local oxidative stress. In this study, a targeted transcriptional assay demonstrates that M . tb exposure to human ALF alters the expression of its cell envelope genes. Specifically, our results indicate that A-ALF-exposed M . tb upregulates cell envelope genes associated with lipid, carbohydrate, and amino acid metabolism, as well as genes associated with redox homeostasis and transcriptional regulators. Conversely, M . tb exposure to E-ALF shows lesser transcriptional response, with most of the M . tb genes unchanged or downregulated. Overall, this study indicates that M . tb responds and adapts to the lung alveolar environment upon contact, and that the host ALF status determined by factors such as age might play an important role in determining infection outcome.

Editorial: Updates from the World Health Organization (WHO) on Global Treatment Recommendations for Drug-Susceptible and Multidrug-Resistant Tuberculosis

The World Health Organization (WHO) estimated that in 2019, 10.0 million people worldwide developed tuberculosis (TB), with 1.4 million deaths from TB in that year. Infection with Mycobacterium tuberculosis that is resistant to at least isoniazid and rifampin and an additional chemotherapeutic agent is known as multidrug-resistant TB (MDR TB). Until recently, the prevalence of drug resistance in patients with TB has been poorly understood due to a lack of infection surveillance and molecular testing. Countries with the highest prevalence of TB, including MDR TB, are also those most affected by the COVID-19 pandemic. The identification of MDR TB requires careful monitoring and resources for molecular testing. Previous treatment regimens have required intravenous treatments of long duration and high cost. The 2020 and 2021 recommendations from the WHO for the management of drug-susceptible TB and MDR TB have included oral treatment regimens and reduced treatment duration. This Editorial aims to present the rationale for the 2020 and 2021 recommendations from the WHO for the management of drug-susceptible TB and MDR TB.

Tuberkulose - Wann daran denken, wie diagnostizieren?

Obwohl die Tuberkulose mithilfe von Antibiotika gut heilbar ist und die Zahlen in Deutschland wieder stetig rückläufig sind, stirbt rechnerisch alle 22 Sekunden auf der Welt ein Mensch an Tuberkulose, 95% davon in Entwicklungs- und Schwellenländern. Die WHO hat in ihrer End-Tuberkulose-Strategie das Ziel formuliert, im Vergleich zu 2015 die Zahl der Tuberkuloseerkrankungen pro 100.000 Einwohner bis 2035 weltweit um 90% und die Zahl der Todesfälle um 95% zu senken. Die Coronakrise hat hier zu großen Rückschritten geführt, fast zwei Drittel der Tuberkuloseprogramme weltweit sind unterbrochen worden. Damit ist in vielen Teilen der Welt die Erreichung dieser Ziele gefährdet und es wird sogar mit zunehmenden Fallzahlen in den nächsten Jahren gerechnet. Aber gerade die Tatsache, dass die Erkrankung bei uns seltener wird führt zu einer Zunahme der Dauer vom ersten Symptom bis zur Tuberkulosediagnose. Der vorliegende Artikel soll Ihnen eine Hilfestellung geben, wann die Tuberkulose in die Differenzialdiagnostik einzubeziehen ist und wie das Krankheitsbild diagnostiziert werden kann. Die Therapie, ihre häufigsten Nebenwirkungen und die Problematik resistenter Tuberkuloseformen werden ebenfalls kurz dargestellt.