Tuberculosis Research Articles

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.

Spatio-temporal analysis of pulmonary tuberculosis in Astambul District, South Kalimantan, Indonesia 2020-2021

Respiratory tuberculosis (TB) remains a significant global health concern and ranks among the top 10 leading causes of death worldwide, following human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). Globally, it is estimated that 1.2 billion people are at risk of being infected with tuberculosis, and Indonesia is the country that contributes the third-highest number of TB cases worldwide, behind China and India. Tuberculosis is still a significant issue in South Kalimantan, notably in Banjar Regency. This study is a descriptive study that intends to identify respiratory TB clusters spatially and temporally in Astambul District during 2020–2021 with the SatScan application, which is visualized as a map of respiratory TB clusters using the Quantum GIS 3.28 application. Data on respiratory TB cases collected from the Banjar District Health Office were examined using retrospective space-time scan statistics, employing a Poisson probability model for analysis. This study found 4 respiratory TB clusters, and 2 of them had significant results, namely in 2020 (RR=6.90, p-value=0.000030) and 2021 (RR=5.27, p-value=0.00003). Factors that affect these clusters are population density, the physical condition of houses, humidity levels, and the availability of health facilities.

RELATIONSHIP BETWEEN BLOOD SUGAR LEVELS AND THE RESULTS OF ACID-FAST BACILLA EXAMINATION IN PULMONARY TUBERCULOSIS PATIENTS

Introduction: Tuberculosis (TB) is a highly contagious disease and a leading cause of morbidity and mortality worldwide. When Mycobacterium tuberculosis enters the body of an individual with elevated blood glucose levels, it creates a favorable environment for bacterial growth and proliferation. Objective: This study aimed to investigate the correlation between blood glucose levels and acid-fast bacilli (AFB) smear results in pulmonary tuberculosis patients at Arifin Achmad General Hospital, Pekanbaru. Methods: This study employed a retrospective analytical correlational design using secondary data from medical records. A total sample of 51 cases was analyzed using total sampling. Data was collected using an observation sheet and analyzed using Fisher's exact test. Results: A majority of the respondents (43%) had blood glucose levels exceeding 125 mg/dl, and a significant proportion (76.5%) had positive AFB smears. The Fisher exact test revealed a significant correlation between blood glucose levels and positive AFB smear results (p < 0.05). Conclusion: This study demonstrates a significant association between blood glucose levels and AFB smear results in pulmonary tuberculosis patients at Arifin Achmad General Hospital, Pekanbaru.

Synthesis and Anti-bacterial Activity of New Substituted 2-trifluoromethyl-4-quinolinylhydrazone Analogs against Mycobacterium tuberculosis Strains.

Tuberculosis (TB) is a serious disease that still affects humanity, despite being old, caused by the bacterium Mycobacterium tuberculosis (Mtb). The emergence of drug-resistant strains has alarmed governments and international organizations, such as the World Health Organization (WHO). The need for research on new drugs that are effective in a shorter treatment time and active against resistant strains still persists. The objective of this study is to synthesize and evaluate forty-four substituted 2-trifluoromethyl-4-quinolinylhydrazone analogs, as probable inhibitors of Mycobacterium tuberculosis growth. The anti-mycobacterial activities of all tested compounds against Mycobacterium tuberculosis strains, as well as the cytotoxicity test, were evaluated using the in vitro microplate procedure with broth microdilution assay. Thirteen compounds exhibited some activity against sensitive strain ATCC 27294, six of which were the most active: 4a, 4c, 6a, 6b, 6c, and 6g; with MIC around 7 - 8 μM, close to that presented by ethambutol (15.9 μM), a drug used in the treatment of tuberculosis. These same compounds also were active against a resistant strain of Mtb (T113), with MIC around 7 - 8 μM. Three of these compounds 4a, 6a, and 6c were not cytotoxic against Vero cells at concentrations near the MIC. This study indicates the importance of the hydrazone function to obtain promising anti-TB compounds and open new perspectives for drug development.

Drug resistance of tuberculosis patients at the makassar city community lung health center hospital: Case Study

Introduction: Drug-resistant tuberculosis (TB-RO) is still a health problem because of its rapid transmission with an increasing number of cases. Objective: This study aims to discover in-depth patient knowledge about tuberculosis and the family's role in treating drug-resistant tuberculosis patients. Methods: This research uses a qualitative case study approach with nine informants. The selection of informants was determined using a purposive sampling technique. Data collection was obtained through interviews and observations. Data analysis was carried out qualitatively. Result: The research shows that informants' knowledge about drug-resistant tuberculosis depends on their educational history. In contrast, informants with low educational backgrounds only know the term tuberculosis but do not know the causes and dangers of drug-resistant tuberculosis. Another thing that was found was that the family also played a role in the patient's treatment by providing support and encouragement for the informant during the treatment period. Conclusion: This research concludes that the informant's knowledge about tuberculosis plays an essential role in the occurrence of drug-resistant tuberculosis. The role of the family does not contribute to the occurrence of drug-resistant tuberculosis in the informant. It can be concluded that the earlier the age of menarche increases the risk of uterine myoma later in life. In contrast, slower menarche may be associated with a reduced risk of myomas. Other factors such as genetic, environmental, and lifestyle factors also influence the incidence of uterine myomas, but menarche age is one of the significant hormonal indicators of risk.

Pooling sputum samples for the Xpert MTB/RIF Ultra assay: a sensitive and effective screening strategy

The sensitivity of Xpert MTB/RIF (Xpert) pooled testing is limited for diagnosing patients with paucibacillary tuberculosis (TB). We assessed whether pooled testing with Xpert MTB/RIF Ultra (Ultra) can be a sensitive and effective approach for mass TB screening. Conserved, frozen sputum samples, previously confirmed as positive or negative for Mycobacterium tuberculosis by individual Xpert assays, were mixed in pools of 4, 8, and 16 and then tested using Ultra. Each pool contained a single positive sample with varying mycobacterial loads. We then simulated TB screening at prevalence ranges of 0.2-1.0% and calculated the cartridges required per case detected at different pool sizes. The overall sensitivity of Ultra pooled testing was high (88.9%, 75.9-96.3). Sensitivity was greater in pools in which the positive sample had a high mycobacterial load compared to those with scant bacilli. As prevalence increased, the optimal pool size and benefits of pooled testing declined, but a pool size of 8 resulted in at least 80% cartridge savings with the highest simulated prevalence. Sputum pooling using Ultra could be a sensitive and effective strategy for TB screening. However, broad TB screening in communities with limited resources will require new, lower-cost, high-throughput screening tools, perhaps based on non-sputum specimens.

Altered intestinal microbiota and fecal metabolites in patients with latent and active pulmonary tuberculosis.

Pulmonary tuberculosis (PTB) is the main cause of infection-related mortality and the most common infectious disease that develops resistance to antibiotics. Gut microbiota and their associated metabolites are assumed to induce and influence the development of PTB. However, the alterations of gut microbiota and metabolites in TB patients is currently unclear. Fecal samples were collected from 13 PTB patients, 13 LTBI patients, and 13 healthy controls (HC). 16S rRNA sequencing and metabolomics were used to analyze the changes in the intestinal microbiota and the composition of fecal metabolites in groups. Our findings indicated that the α-diversity of the gut microbiota in patients with PTB and LTBI decreases compared to HC, and at the phylum level, the relative abundance of Firmicutes decreases and the relative abundance of Bacteroides increases. And six genera were notably enriched in PTB patients and four in LTBI patients. Metabolomic analysis showed alterations in metabolite levels, such as short-chain fatty acids and amino acids. we comprehensively explored the changes in the gut microbes and fecal metabolites in patients with PTB and LTBI from the perspective of the gut microbiota, which may provide potential diagnostic biomarkers and therapeutic targets for TB diagnosis and treatment.

A simplified pyrazinamidase test for Mycobacterium tuberculosis pyrazinamide antimicrobial susceptibility testing

ABSTRACT Pyrazinamide (PZA) is an important first-line drug for tuberculosis (TB) treatment by eradicating the persisting Mycobacterium tuberculosis complex (MTBC). Due to cost and technical challenges, end TB strategies are hampered by the lack of a simple and reliable culture-based PZA antimicrobial susceptibility testing (AST) for routine use. We initially developed a simplified chromogenic pyrazinamidase (PZase) test in the TB reference laboratory using a training set MTBC isolates with various drug-resistant profiles, and validated its performance using consecutive BACTEC MGIT 960 (MGIT)-culture-positive culture in 10 clinical laboratories. The pncA gene Sanger sequencing results were used as the reference, and compared to the MGIT-PZA AST. Differential diagnosis of Mycobacterium bovis was conducted using patented in-house real-time PCR. Of the 106 training isolates, the PZase test and MGIT-PZA AST showed 100.0% and 99.1% concordance as compared to Sanger sequencing, respectively. We found 32.1% (34/106) isolates harbored pncA mutations, including one isolate with silent mutation S65S. For validation, 1,793 clinical isolates were tested including 150 duplicate isolates from specimens of the same cases and 16 isolates with uncharacterized drug resistance (UDR)-associated mutations. Excluding duplicated and UDR isolates, we identified 2.6% (43/1,627) PZA-resistant isolates, including 1.3% (21/1,627) M . bovis isolates. The kappa values were 0.851–1.000. In addition, the accuracy of the PZase test conducted by 10 laboratories was 98.5%–100.0%. Our simplified PZase test demonstrated high concordance with Sanger sequencing and MGIT-PZA AST. Integrating the PZase test into routine first-line AST is effortless and represents an improvement in laboratory services for ending TB. IMPORTANCE We developed and validated a simple pyrazinamidase (PZase) test for pyrazinamide (PZA) antimicrobial susceptibility testing (AST). Our results demonstrated that the PZase test had high agreement with the pncA gene sequencing and MGIT-PZA AST. Integrating PZase test into routine AST is effortless and represents an improvement in laboratory services for ending TB.

Implications of Asymptomatic Carriers for Tuberculosis Transmission and Control in Thailand: A Modelling Approach

Tuberculosis (TB) is a regional and global bacterial illness that has been expanding and affecting individuals in every generation. An unknown percentage of asymptomatic hosts have TB, and the infection can spread while exhibiting no symptoms. These asymptomatic TB carriers, who contribute to the spread of the illness yet go mostly undetected, may make it more difficult to prevent transmission. In this study, we utilized the concept of symmetry to construct a manageable disease modelling framework for TB transmission and control. We developed a TB model to investigate the potential influence of asymptomatic carriers, symptomatic infections, and the entirety of TB prevalence on different approaches to treatment and prevention in Thailand. Annual TB incidence data from Thailand from 2000 to 2022 were used to calibrate the model parameters. We assessed the potential for reaching conflicting results about the management and spread of tuberculosis in Thailand. Our results showed that some TB strategies that were thought to be effective in reducing transmission may have the opposite impact, or that an intervention’s effectiveness might be overestimated, making it seem unfeasible in certain scenarios. For example, the objective of TB treatment, which attempts to decrease the occurrence of symptomatic TB infections, is to decrease the TB infection and propagation rates if the relative carrier (η) is less than one. Nonetheless, our results indicate that this strategy may increase the frequency of asymptomatic TB patients, symptomatic TB viral infections, and overall TB prevalence if η has been sufficiently understated. We also found that reducing only the progression rate of symptomatic TB infections cannot stop asymptomatic TB carriers and total TB prevalence, even when the relative infection of carriers (η) is less than unity. Our research provides a better understanding of the role of asymptomatic patients in spreading TB and highlights the need to accurately include bearers in models that guide Thailand’s TB control strategy.

Foregut tuberculosis: Too close but miles apart

The worldwide burden of tuberculosis (TB) has increased and it can involve virtually any organ of the body. Intestinal TB accounts for about 2% of the cases of TB worldwide. The ileocecal region is the most commonly affected site, and the foregut is rarely involved. The reported incidence is approximately 0.5%. Esophageal TB presents with dysphagia, weight loss, and hematemesis in rare cases. Gastroduodenal TB usually manifests with symptoms such as nausea, vomiting, weight loss, and sometimes with gastric outlet obstruction. Gastroscopy may reveal shallow ulcers in stomach and duodenal deformity when underlying TB is suspected, therefore histopathology plays pivotal role. On computed tomography, duodenal TB typically manifests as duodenal strictures predominantly, accompanied by extrinsic compression, and occasionally as intraluminal mass. But their diagnosis can easily be missed if proper biopsies are not taken and samples are not sent for GeneXpert testing, TB polymerase chain reaction investigation and histopathological analysis. Despite being in close proximity to the lungs, the esophagus and stomach are rare sites of TB. The reasons could be low gastric pH and acidity which does not let mycobacterium grow. But there are various case reports of TB involving the foregut. We have summarized the rare cases of foregut TB in different sections and highlighted the importance of esophagogastroduodenoscopy, histopathology and advanced techniques like endoscopic ultrasound in establishing the diagnosis.

Machine learning model based on SERPING1, C1QB, and C1QC: A novel diagnostic approach for latent tuberculosis infection

AbstractBackgroundLatent tuberculosis infection (LTBI) is a significant source of active tuberculosis (ATB), yet distinguishing between them is challenging because specific biomarkers are lacking.MethodsWe analyzed four microarray datasets (GSE19491, GSE37250, GSE54992, GSE28623) from the gene expression omnibus to identify differentially expressed genes (DEGs). Using protein–protein interaction (PPI) networks and LASSO‐SVM algorithms, we selected three candidate biomarkers and evaluated their diagnostic efficacy. The expression levels of core genes were validated by RNA sequencing of healthy, ATB, and LTBI groups in a real‐world cohort. We conducted Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, predicted shared upstream miRNAs, constructed miRNA–hub and transcription factor (TF)–hub gene networks, and performed immune infiltration analysis.ResultsThree hub genes (SERPING1, C1QC, C1QB) were identified from 45 DEGs by PPI networks and machine learning screening. The diagnostic model based on the three hub genes had an area under the curve (AUC) value of 0.843 in the training set GSE19491 and 0.865 in the validation set GSE28623. Real‐world transcriptome sequencing confirmed the expression trends of the hub genes across healthy, LTBI, and ATB groups. GO analysis showed that the 45 hub genes were primarily associated with immune inflammatory responses and pattern recognition receptors, whereas KEGG analysis indicated enrichment in complement and coagulation cascades. The miRNA–hub and TF–hub gene network analysis identified nine miRNAs and the zinc finger TF GATA2 as potential co‐regulators of SERPING1, C1QC, and C1QB. Immune cell infiltration analysis identified significant differences in the immune microenvironment between LTBI and ATB, with macrophages and natural killer cells showing significant correlations with tuberculosis infection.ConclusionThe diagnostic model with SERPING1, C1QC, and C1QB shows promise in distinguishing LTBI from ATB, indicating its potential as a diagnostic tool.

Stigma in tuberculosis patients: a cross-sectional study in the southeast region of Turkey.

Since tuberculosis (TB) is an infectious disease, it affects patients not only physically but also socially and patients are reported to experience stigma. This study was conducted to determine the stigma levels of patients in a tuberculosis dispensary in the southeastern region of Turkey. The study was conducted between December 2020 and June 2021 with 79 patients who agreed to participate. 'Questionnaire' and 'Tuberculosis-Related Stigma Scale' (TSS) were used for data collection. The score obtained from the scale ranges between '33 and 132' and the higher the score, the higher the 'stigma level'. It was determined that 54.4% of the patients were male, 45.6% were primary school and the mean age was 44.98 ± 16.09 years. It was found that 60.8% of the patients had pulmonary TB, 40.5% had been on treatment for 3-6 months, 45.6% described the society's view of TB patients as 'bad, negative, and excluding', 64.8% had adverse effects on their communication with their family and close environment after being diagnosed with TB. The mean TSS score of the patients was 103.51 ± 10.65. TB patients were found to have 'very high' levels of stigma. The mean total stigma is higher in smokers, particularly in cases of pulmonary and extrapulmonary tuberculosis, as well as in those whose professional lives are affected.

Osteoarticular tuberculosis: imaging findings in pediatric patients.

Osteoarticular tuberculosis (TB) is an uncommon form of extrapulmonary TB that has the potential to damage joints and bones, generating long-term impairment. Mainly, the initial diagnosis of osteoarticular TB relies on clinical findings and imaging. When required, imaging can aim for less invasive tissue or fluid sampling for pathology, microbiology, and molecular biology analysis. Most TB diagnosis tests have variable and frequently poor sensitivities; however, bone biopsy samples have demonstrated a high percentage of culture positivity. Clinical and imaging findings of osteoarticular TB often mimic other processes, such as rheumatoid arthritis or chronic recurrent multifocal osteomyelitis. When the infection affects the growth plates, angular deformities and extremity length discrepancies can arise. Unfortunately, several osteoarticular TB cases are detected late due to the nonspecific nature of clinical symptoms and non-characteristic imaging findings. This article reviews the most common and atypical osteoarticular TB imaging presentations to increase awareness of osteoarticular TB.

Analysis of a fractional order epidemiological model for tuberculosis transmission with vaccination and reinfection.

This study has been carried out using a novel mathematical model on the dynamics of tuberculosis (TB) transmission considering vaccination, endogenous re-activation of the dormant infection, and exogenous re-infection. We can comprehend the behavior of TB under the influence of vaccination from this article. We compute the basic reproduction number ( ) as well as the vaccination reproduction number ( ) using the next-generation matrix (NGM) approach. The theoretical analysis demonstrates that the disease-free equilibrium point is locally asymptotically stable, and the fractional order system is Ulam-Hyers type stable. We perform numerical simulation of our model using the Adams-Bashforth 3-step method to verify the theoretical results and to show the model outputs graphically. By performing data fitting, we observe that our formulated model produces results that closely match real-world data. Our findings indicate that vaccinating a limited segment of the population can effectively eradicate the disease. The numerical simulations also show that vaccination can reduce the number of susceptible and infectious individuals in the population. Moreover, the graphical representations illustrate that the number of infected individuals rises due to both exogenous reinfection and endogenous reactivation.

Assessment of Sex Hormones (FSH, LH, Prolactin, Estrogen, Progesterone and Testosterone) of Pulmonary Tuberculosis Patients

Background: Tuberculosis (TB) is a one of the major global health problems ranking as the eighth leading cause of death in low- and middle-income countries. This study was carried out to evaluate the Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH), Prolactin, Estrogen, Progesterone and Testosterone of pulmonary tuberculosis patients in Edo State. Objectives: The objectives of the study are to assess the FSH, LH, Prolactin, Estrogen, Progesterone and Testosterone levels of Pulmonary Tuberculosis (PTB) patients compared with control, hormonal levels of PTB patients of new case, 2 months and 6 months therapy compared with control, hormonal levels of PTB patients in relation to gender and hormonal levels of PTB patients in relation to age. Material and methods: A total of 120 samples were used in this study comprising PTB new cases (30), PTB 2 months therapy (30), PTB 6 months therapy (30) and Control (30) respectively. FSH, LH, Prolactin, Estrogen, Progesterone and Testosterone were measured by Enzyme-Linked Immunoassay Test (ELISA). The results were presented using tables as mean ± standard deviation. Statistical analysis was done using one-way Analysis of Variance (ANOVA) and the student’s t-test. Significant difference was accepted at p<0.05. Results: The results obtained showed that the FSH (mIU/ml) of new case subjects, 2 months on therapy, 6 months on therapy and control were 13.42±3.58, 11.38±3.04, 6.52±2.57 and 8.71±3.15; LH (mIU/ml) was 10.43±2.95, 8.32±2.44, 5.21±2.23 and 6.05±2.44; prolactin (µg/L) was 10.17±4.04, 9.47±2.56, 10.11±6.74 and 12.96±7.09; estrogen (pg/ml) was 35.97±9.27, 41.50±12.65, 57.60±17.46 and 64.97±29.24, progesterone (ng/ml) was 0.18±0.05, 0.25±0.06, 0.40±0.10 and 0.37±0.08; and testosterone (ng/ml) was 2.49±0.95, 2.48±1.46, 4.00±2.92 and 4.32±3.84 respectively. Conclusion: In conclusion, there was significant difference (p<0.05) in the FSH, LH, Prolactin, Estrogen, Progesterone and Testosterone of the subjects in the different groups compared with control. FSH, LH, Prolactin, Estrogen and Progesterone were significantly higher (p<0.05) in female subjects compared with male subjects, while Testosterone was non-significantly (p>0.05) higher in male subjects compared with female subjects.

Integrated virtual screening and MD simulation study to discover potential inhibitors of mycobacterial electron transfer flavoprotein oxidoreductase.

Tuberculosis (TB) continues to be a major global health burden, with high incidence and mortality rates, compounded by the emergence and spread of drug-resistant strains. The limitations of current TB medications and the urgent need for new drugs targeting drug-resistant strains, particularly multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB, underscore the pressing demand for innovative anti-TB drugs that can shorten treatment duration. This has led to a focus on targeting energy metabolism of Mycobacterium tuberculosis (Mtb) as a promising approach for drug discovery. This study focused on repurposing drugs against the crucial mycobacterial protein, electron transfer flavoprotein oxidoreductase (EtfD), integral to utilizing fatty acids and cholesterol as a carbon source during infection. The research adopted an integrative approach, starting with virtual screening of approved drugs from the ZINC20 database against EtfD, followed by molecular docking, and concluding with molecular dynamics (MD) simulations. Diacerein, levonadifloxacin, and gatifloxacin were identified as promising candidates for repurposing against TB based on their strong binding affinity, stability, and interactions with EtfD. ADMET analysis and anti-TB sensitivity predictions assessed their pharmacokinetic and therapeutic potential. Diacerein and levonadifloxacin, previously unexplored in anti-tuberculous therapy, along with gatifloxacin, known for its efficacy in drug-resistant TB, have broad-spectrum antimicrobial properties and favorable pharmacokinetic profiles, suggesting potential as alternatives to current TB treatments, especially against resistant strains. This study underscores the efficacy of computational drug repurposing, highlighting bacterial energy metabolism and lipid catabolism as fruitful targets. Further research is necessary to validate the clinical suitability and efficacy of diacerein, levonadifloxacin, and gatifloxacin, potentially enhancing the arsenal against global TB.

Nurse training to enhance adherence counselling for HIV-tuberculosis coinfection in South Africa: Integrative review

Background: South Africa has seen strides in reducing HIV and tuberculosis (TB); however, adherence counselling for people living with HIV (PLHIV) coinfected with TB remains a challenge, particularly in specific sub-districts like Cape Town. Understanding the attributes of existing training programmes is crucial.Objectives: This study explored attributes of training programme development for nurses and other health professionals to enhance adherence counselling for PLHIV coinfected with TB in Cape Town.Method: An integrative literature review was conducted in five steps following PRISMA guidelines. Electronic searches encompassed multiple databases: COCHRANE, PsycINFO, PUBMED, ENMBASE, Science Direct, SCOPUS, SocINDEX, Academic Search Complete, Eric, SABINET, Health Resources and World Health Organization Global Health Library Regional Indexes. Inclusion criteria encompassed English language, peer-reviewed full-text studies on training programme development, qualitative and quantitative, published between January 2012 and May 2021. Exclusion criteria included non-English articles, conference proceedings and irrelevant studies. Thematic data analysis synthesised findings.Results: Three main themes emerged: participant identification, key programme content and programme implementation process, crucial for effective training programme development.Conclusion: Identifying participants, defining programme content and outlining implementation processes are pivotal in enhancing nurses’ adherence counselling skills. This approach could stabilise patient treatment adherence, potentially reducing treatment default, loss to follow-up and mortality rates.Contribution: These findings lay the groundwork for developing effective training programmes aimed at improving adherence counselling among nurses.

The role of antibiotic-derived mycobacterial vesicles in tuberculosis pathogenesis.

Pulmonary tuberculosis (TB) causes progressive and irreversible damage to lung tissue, a damage that may not fully resolve after treatment. Mycobacterial vesicles (MVs), which are poorly understood, may contribute to TB pathology. This study investigated the effects of stress, such as treatment with conventional TB antibiotics rifampicin, isoniazid, ethambutol, or treatment with an antimycobacterial peptide (NZX), on mycobacterial vesiculation. Stress from minimal inhibitory concentrations of antibiotics, or peptide all increased MV formation. Electron microscopy and lipid profiling revealed that these vesicles, about 40nm in size, were released from the bacterial inner membrane and consisted of apolar lipids. Using mass spectrometry, the study identified key differences in MVs protein cargo dependent on the antibiotic used, especially with ethambutol-induced MVs that contained proteins from several mycobacterial pathways. Additionally, toxicology analysis using different concentrations of MVs on primary human macrophages and the monocytic cells indicated that MVs from the different treatments were not toxic to human cells, however induced specific inflammatory profiles. In conclusion, this study identified mycobacterial vesicles to be a potential contributor to tuberculosis pathology.

Sirtuin inhibitors reduce intracellular growth of M. tuberculosis in human macrophages via modulation of host cell immunity.

Host-directed therapies aiming to strengthen the body's immune system, represent an underexplored opportunity to improve treatment of tuberculosis (TB). We have previously shown in Mycobacterium tuberculosis (Mtb)-infection models and clinical trials that treatment with the histone deacetylase (HDAC) inhibitor, phenylbutyrate (PBA), can restore Mtb-induced impairment of antimicrobial responses and improve clinical outcomes in pulmonary TB. In this study, we evaluated the efficacy of different groups of HDAC inhibitors to reduce Mtb growth in human immune cells. A panel of 21 selected HDAC inhibitors with different specificities that are known to modulate infection or inflammation was tested using high-content live-cell imaging and analysis. Monocyte-derived macrophages or bulk peripheral blood cells (PBMCs) were infected with the green fluorescent protein (GFP)-expressing Mtb strains H37Ra or H37Rv and treated with HDAC inhibitors in the micromolar range in parallel with a combination of the first-line antibiotics, rifampicin, and isoniazid. Host cell viability in HDAC inhibitor treated cell cultures was monitored with Cytotox-red. Seven HDAC inhibitors were identified that reduced Mtb growth in macrophages > 45-75% compared to average 40% for PBA. The most effective compounds were inhibitors of the class III HDAC proteins, the sirtuins. While these compounds may exhibit their effects by improving macrophage function, one of the sirtuin inhibitors, tenovin, was also highly effective in extracellular killing of Mtb bacilli. Antimicrobial synergy testing using checkerboard assays revealed additive effects between selected sirtuin inhibitors and subinhibitory concentrations of rifampicin or isoniazid. A customized macrophage RNA array including 23 genes associated with cytokines, chemokines and inflammation, suggested that Mtb-infected macrophages are differentially modulated by the sirtuin inhibitors as compared to PBA. Altogether, these results demonstrated that sirtuin inhibitors may be further explored as promising host-directed compounds to support immune functions and reduce intracellular growth of Mtb in human cells.

Small Molecule Inhibitors of Mycobacterium tuberculosis Topoisomerase I Identified by Machine Learning and In Vitro Assays

Tuberculosis (TB) caused by Mycobacterium tuberculosis is a leading infectious cause of death globally. The treatment of patients becomes much more difficult for the increasingly common multi-drug resistant TB. Topoisomerase I is essential for the viability of M. tuberculosis and has been validated as a new target for the discovery of novel treatment against TB resistant to the currently available drugs. Virtual high-throughput screening based on machine learning was used in this study to identify small molecules that target the binding site of divalent ion near the catalytic tyrosine of M. tuberculosis topoisomerase I. From the virtual screening of more than 2 million commercially available compounds, 96 compounds were selected for testing in topoisomerase I relaxation activity assay. The top hit that has IC50 of 7 µM was further investigated. Commercially available analogs of the top hit were purchased and tested with the in vitro enzyme assay to gain further insights into the molecular scaffold required for topoisomerase inhibition. Results from this project demonstrated that novel small molecule inhibitors of bacterial topoisomerase I can be identified starting with the machine-learning-based virtual screening approach.