Identification of Novel Antimicrobial Compounds Targeting Mycobacterium tuberculosis S-Adenosyl-L-Homocysteine Hydrolase Using Dual Hierarchical In Silico Structure-Based Drug Screening.

The emergence of multidrug-resistant and extensively drug-resistant Mycobacterium tuberculosis (M. tuberculosis) has become a major medical problem. S-adenosyl-L-homocysteine hydrolase (MtSAHH) was selected as the target protein for the identification of novel anti-TB drugs. Dual hierarchical in silico Structure-Based Drug Screening was performed using a 3D compound structure library (with over 150 thousand synthetic chemicals) to identify compounds that bind to MtSAHH's active site. In vitro experiments were conducted to verify whether the nine compounds selected as new drug candidates exhibited growth-inhibitory effects against mycobacteria. Eight of the nine compounds that were predicted by dual hierarchical screening showed growth-inhibitory effects against Mycobacterium smegmatis (M. smegmatis), a model organism for M. tuberculosis. Compound 7 showed the strongest antibacterial activity, with an IC50 value of 30.2 µM. Compound 7 did not inhibit the growth of Gram-negative bacteria or exert toxic effects on human cells. Molecular dynamics simulations of 40 ns using the MtSAHH-Compound 7 complex structure suggested that Compound 7 interacts stably with the MtSAHH active site. These in silico and in vitro results suggested that Compound 7 is a promising lead compound for the development of new anti-TB drugs.

Fetal protective effect of Indonesian propolis from Apis mellifera against rifampicin-pyrazinamide induced impaired pregnancy in BALB/c mice.

OBJECTIVES: Anti-tuberculosis drugs rifampicin and pyrazinamide combination in pregnancy can cause morphological, visceral and skeletal damage. Several studies showed that propolis improves pregnancy outcomes. This study aims to determine the fetal protective effect of propolis in BALB/c mice given the anti-tuberculosis drug combination rifampicin and pyrazinamide. METHODS: A total of 21 pregnant mice were randomly divided into three groups: the normal group (N) was given distilled water as a vehicle, the positive control group (RP) were given rifampicin 15 mg/kg BW, pyrazinamide 35 mg/kg BW and the treatment group (IP) were given rifampicin 15 mg/kg BB, pyrazinamide 35 mg/kg BW and propolis 400 mg/kg BW. The treatment was given during the period of organogenesis, from day 6 to day 15. Laparotomy was performed on the 18th day of pregnancy. Maternal and fetal body weight, fetal length, number of fetuses, and skeletal defects of fetuses were used as parameters to identify the teratogenic effect. All data were analyzed using the ANOVA. RESULTS: All groups significantly differed between maternal and fetal body weights (p<0.05). The administration of rifampicin-pyrazinamide and propolis during pregnancy did not significantly affect the number of fetuses (p>0.05). The administration of propolis protects the fetus from skeletal abnormalities. While in the RP and IP groups, we can find resorption sites and haemorrhagic. CONCLUSIONS: This study may suggest the protective effects of propolis against rifampicin pyrazinamide-induced impaired pregnancy.

Progress and challenges in achieving tuberculosis elimination in India by 2025: A systematic review and meta-analysis.

BACKGROUND: Tuberculosis (TB) continues to pose a significant public health challenge in India, which is home to one of the highest TB burdens worldwide. This systematic review and meta-analysis will aim to synthesize the anticipated progress and potential challenges in achieving TB elimination in India by 2025. METHODS: A comprehensive search will be conducted across multiple databases, including PubMed, Scopus, and Web of Science, to identify relevant studies. The eligibility criteria will encompass individuals diagnosed with TB in India, interventions targeting TB treatment, prevention, or control, and various comparator groups. Outcomes of interest will include incidence reduction, mortality rate, treatment success rate, barriers to TB care, and more. Both quantitative and qualitative data will be synthesized, and the risk of bias will be assessed using established tools. OUTCOMES: The review is expected to provide a holistic understanding of the TB landscape in India, highlighting the effective interventions and potential challenges in the journey towards TB elimination. CONCLUSIONS: While it is anticipated that significant progress will be made in the fight against TB in India, challenges are likely to persist. This review will offer a comprehensive roadmap for researchers, policymakers, and healthcare professionals, emphasizing the importance of continued efforts, innovative strategies, and a multi-pronged approach in achieving the goal of TB elimination in India by 2025.

Compliance with new drug use and the effect of discrepant drug susceptibility testing on MDR/RR-TB treatment.

BACKGROUND: Following the WHO???s announcement in 2018, the use of new drugs was recommended for all patients with multidrug-resistant TB (MDR-TB) in Korea. This study aimed to evaluate adherence to new anti-TB drug regimens and implementation of molecular drug susceptibility testing (mDST) in Korea.METHODS: Nationwide, 560 patients were reported as having MDR-TB in 2021. The implementation of mDST and new anti-TB drug use were analysed. The discrepancy between mDST and phenotypic DST (pDST) results and their implications on the use of new anti-TB drugs were also analysed. The use of novel anti-TB drugs has been approved by the National TB Expert Committee.RESULTS: The non-adherence rate in MDR-TB patients was 14.3%. The mDST implementation rate was 96.1%. Of the 459 patients who underwent both mDST and pDST, the discordance rate for rifampicin (RIF) resistance was 22.6% (n = 104), of which 72.1% (n = 75) were resistant on mDST but susceptible on pDST. The discrepancy in mDST and pDST results related to RIF resistance was found to be the main cause of non-adherence to new drug regimen.CONCLUSION: Comprehensive training on how to interpret conflicting results between mDST and pDST could enhance the utilisation of new drugs in the treatment of MDR/RIF-resistant TB.

Second-line antituberculosis drug exposure thresholds predictive of adverse events in multidrug-resistant tuberculosis treatment.

OBJECTIVES: This study aimed to investigate the association between drug exposure and adverse events (AEs) during the standardized multidrug-resistant tuberculosis (MDR-TB) treatment, as well as to identify predictive drug exposure thresholds. METHODS: We conducted a prospective, observational multicenter study among participants receiving standardized MDR-TB treatment between 2016 and 2019 in China. AEs were monitored throughout the treatment and their relationships to drug exposure (e.g., the area under the drug concentration-time curve from 0 to 24 h, AUC0-24 h) were analyzed. The thresholds of pharmacokinetic predictors of observed AEs were identified by boosted classification and regression tree (CART) and further evaluated by external validation. RESULTS: Of 197 study participants, 124 (62.9%) had at least one AE, and 15 (7.6%) experienced serious AEs. The association between drug exposure and AEs was observed including bedaquiline, its metabolite M2, moxifloxacin and QTcF prolongation (QTcF >450 ms), linezolid and mitochondrial toxicity, cycloserine and psychiatric AEs. The CART-derived thresholds of AUC0-24 h predictive of the respective AEs were 3.2 mg·h/l (bedaquiline M2); 49.3 mg·h/l (moxifloxacin); 119.3 mg·h/l (linezolid); 718.7 mg·h/l (cycloserine). CONCLUSIONS: This study demonstrated the drug exposure thresholds predictive of AEs for key drugs against MDR-TB treatment. Using the derived thresholds will provide the knowledge base for further randomized clinical trials of dose adjustment to minimize the risk of AEs.

Quinoline Derivatives as Promising Scaffolds for Antitubercular Activity: A Comprehensive Review.

BACKGROUND: Heterocyclic compounds and their derivatives play a significant role in the design and development of novel quinoline drugs. Among the various pharmacologically active heterocyclic compounds, quinolines stand out as the most significant rings due to their broad pharmacological roles, specifically antitubercular activity, and their presence in plant-based compounds. Quinoline is also known as benzpyridine, benzopyridine, and 1-azanaphthalene. It has a benzene ring fused with a pyridine ring, and both rings share two carbon atoms. The importance of quinoline lies in its incorporation as a key component in various natural compounds found in medicinal plant families like Fumariaceae, Berberidaceae, Rutaceae, Papavaraceae, and others. OBJECTIVE: This article is expected to have a significant impact on the advancement of effective antitubercular drugs. Through harnessing the potent activity of quinoline derivatives, the research aims to make valuable contributions to combating tuberculosis more efficiently and ultimately reducing the global burden of this infectious disease. METHODS: Numerous nitrogen-containing heterocyclic compounds exhibit significant potential as antitubercular agents. These chemicals have fused aromatic nitrogen-heterocyclic nuclei that can change the number of electrons they have, which can change their chemical, physical, and biological properties. This versatility comes from their ability to bind with the receptors in multiple modes, a critical aspect of drug pharmacological screening. Among these compounds, quinoline stands out as it incorporates a stable fusion of a benzene ring with a pyridine nucleus. Quinolines have demonstrated a diverse range of pharmacological activities, including but not limited to anti-tubercular, anti-tumor, anticoagulant, anti-inflammatory, antioxidant, antiviral, antimalarial, anti-HIV, and antimicrobial effects. RESULTS: Some molecules, such as lone-paired nitrogen species, include pyrrole, pyrazole, and quinoline. These molecules contain nitrogen and take part in metabolic reactions with other molecules inside the cell. However, an excessive accumulation of reactive nitrogen species can lead to cytotoxicity, resulting in damage to essential biological macromolecules. Among these compounds, quinoline stands out as the oldest and most effective one, exhibiting a wide range of significant properties such as antitubercular, antimicrobial, anti-inflammatory, antioxidant, analgesic, and anticonvulsant activities. Notably, naturally occurring quinoline compounds, such as quinine, have proven to be potent antimalarial drugs. CONCLUSION: This review highlights quinoline derivatives' antitubercular potential, emphasizing recent research advancements. Utilizing IC50 values, the study emphasizes the efficacy of various quinoline substitutions, hybrids, and electron-withdrawing groups against MTB H37Rv. Continued research is essential for developing potent, low-toxicity quinoline derivatives to combat tuberculosis.

Bilateral hand dactylitis: An unusual presentation of the great imitator: Tuberculosis.

The incidence of tuberculosis in developed countries has decreased over the years due to the use of effective tuberculosis drugs and improvements in socio-economic conditions. However, with the ease of global transport and increased travel to countries with high tuberculosis prevalence, the reduction in extrapulmonary tuberculosis cases has been less significant compared with the overall decrease in tuberculosis cases. Extrapulmonary tuberculosis can manifest in a variety of ways. Tuberculous dactylitis, a rare form of tuberculous osteomyelitis, was first described by Rankin in 1886. It mainly affects the short tubular bones in the hands and feet of children and is sometimes called 'spina ventosa'. A 42-year-old male patient initially presented to an external centre reporting swelling and pain in the hand joints of one year's duration. Despite one year of treatment with leflunomide and methylprednisolone (16 mg) and a history of methotrexate use during this period, he experienced no improvement. The patient's condition worsened after the start of sulfasalazine. Dermatological examination was performed due to the presence of haemorrhagic crusted papules and plaques on the ventral surface of both hands. A wound culture was taken, but no bacterial growth was observed. One week after the initial evaluation, the patient complained of persistent foul-smelling nasal discharge, which led to an evaluation by the infectious disease department. At this time, the Quantiferon test was positive. Mycobacterial culture on Days 1 and 3 showed growth of the Mycobacterium tuberculosis complex.

Unveiling foot tuberculosis as an under-recognized source of foot pain.

PURPOSE: Foot tuberculosis is a rare form of osteoarticular tuberculosis, accounting for less than 1% of cases. It presents unique diagnostic challenges due to its nonspecific clinical features and overlapping symptoms with other conditions. This study aimed to investigate the clinical presentation, radiographic findings, and prognosis of foot tuberculosis, with the goal of improving early recognition and appropriate intervention. METHODS: A prospective study was conducted between November 2016 and July 2021, involving 39 patients diagnosed with foot tuberculosis. Clinical examinations, laboratory tests, X-rays, and MRI evaluations were performed to aid in the diagnosis. Biopsy was conducted on patients with radiological lesions. Patients were treated with an 18-month course of antitubercular therapy (ATT). Foot Function Index (FFI) scores were recorded before and after treatment. Statistical analysis was conducted to assess factors impacting prognosis. RESULTS: Unilateral foot involvement was observed in all patients, with a male predominance (61.5%) and a mean age of 31.3 years. The most common symptoms were pain and edema, with sinus tracts present in 17.9% of patients. Radiographic findings showed cystic and sclerotic lesions, with the "spina ventosa" appearance primarily affecting the metatarsal bones. MRI played a valuable role in early detection. Histopathological examination confirmed tuberculosis in all cases, and acid-fast bacilli were found in 23% of patients. Most patients (79.4%) responded well to ATT without requiring surgery. Factors such as high initial ESR, delayed ATT initiation, multiple lesions, and tarsal involvement were associated with unfavourable outcomes. CONCLUSION: Foot tuberculosis presents with nonspecific symptoms, leading to misdiagnosis and delays in appropriate treatment. Clinical examination, radiographic evaluation, and biopsy are essential for accurate diagnosis. Early initiation of ATT is crucial for favourable outcomes. Factors such as high initial ESR, delayed treatment initiation, multiple lesions, and tarsal involvement negatively impact prognosis. This study highlights the importance of recognizing foot tuberculosis and provides insights into its clinical presentation, radiographic features, and treatment outcomes, facilitating timely intervention and improved patient management.

No action is without its side effects: Adverse drug reactions and missed doses of antituberculosis therapy, a scoping review.

AIMS: A key reason for the failure of antituberculosis (anti-TB) treatment is missed doses (instances where medication is not taken). Adverse drug reactions (ADRs) are 1 cause of missed doses, but the global evidence, their relative contribution to missed doses vs. other causes, the patterns of missed doses due to ADRs and the specific ADRs associated with missed doses have not been appraised. We sought to address these questions through a scoping review. METHODS: MEDLINE, Embase and Web of Science were searched on 3 November 2021 using terms around active TB, missed doses and treatment challenges. Studies reporting both ADR and missed dose data were examined (PROSPERO: CRD42022295209). RESULTS: Searches identified 108 eligible studies: 88/108 (81%) studies associated ADRs with an increase in missed doses; 33/61 (54%) studies documenting the reasons for missed doses gave ADRs as a primary reason. No studies examined patterns of missed doses due to ADRs; 41/108 (38%) studies examined associations between 68 types of ADR (across 15 organ systems) and missed doses. Nuance around ADR-missed doses relations regarding drug susceptibility testing profile and whether the missed doses originated from the patient, healthcare professionals, or both were found. CONCLUSION: There is extensive evidence that ADRs are a key driver for missed doses of anti-TB treatment. Some papers examined specific ADRs and none evaluated the patterns of missed doses due to ADRs, demonstrating a knowledge deficit. Knowing why doses both are and are not missed is essential in providing targeted interventions to improve treatment outcomes.

A descriptive study on isoniazid resistance-associated mutations, clustering and treatment outcomes of drug-resistant tuberculosis in a high burden country.

PURPOSE: To describe katG and inhA mutations, clinical characteristics, treatment outcomes and clustering of drug-resistant tuberculosis (TB) in the State of São Paulo, southeast Brazil. METHODS: Mycobacterium tuberculosis isolates from patients diagnosed with drug-resistant TB were screened for mutations in katG and inhA genes by line probe assay and Sanger sequencing, and typed by IS6110-restriction fragment-length polymorphism for clustering assessment. Clinical, epidemiological and demographic data were obtained from surveillance information systems for TB. RESULTS: Among the 298 isolates studied, 127 (42.6%) were isoniazid-monoresistant, 36 (12.1%) polydrug-resistant, 93 (31.2%) MDR, 16 (5.4%) pre-extensively drug-resistant (pre-XDR), 9 (3%) extensively drug-resistant (XDR) and 17 (5.7%) susceptible after isoniazid retesting. The frequency of katG 315 mutations alone was higher in MDR isolates, while inhA promoter mutations alone were more common in isoniazid-monoresistant isolates. Twenty-six isolates phenotypically resistant to isoniazid had no mutations either in katG or inhA genes. The isolates with inhA mutations were found more frequently in clusters (75%) when compared to the isolates with katG 315 mutations (59.8%, p = 0.04). In our population, being 35-64 years old, presenting MDR-, pre-XDR- or XDR-TB and being a retreatment case were associated with unfavourable TB treatment outcomes. CONCLUSION: We found that katG and inhA mutations were not equally distributed between isoniazid-monoresistant and MDR isolates. In our population, clustering was higher for isolates with inhA mutations. Finally, unfavourable TB outcomes were associated with specific factors.

Pharmacokinetic assessment of rifampicin and des-acetyl rifampicin in carbon tetrachloride induced liver injury model in Wistar rats.

OBJECTIVES: Preclinical evidence is needed to assess drug-metabolite behaviour in compromised liver function for developing the best antitubercular treatment (ATT) re-introduction regimen in drug-induced liver injury (DILI). The pharmacokinetic behavior of rifampicin (RMP) and its active metabolite des-acetyl-rifampicin (DARP) in DILI's presence is unknown. To study the pharmacokinetic behavior of RMP and DARP in the presence of carbon tetrachloride (CCl4) plus ATT-DILI in rats. METHODS: Thirty rats used in the experiment were divided equally into six groups. We administered a single 0.5 mL/kg CCl4 intraperitoneal injection in all rats. Groups II, III, IV, and V were started on daily oral RMP alone, RMP plus isoniazid (INH), RMP plus pyrazinamide (PZA), and the three drugs INH, RMP, and PZA together, respectively, for 21-days subsequently. Pharmacokinetic (PK) sampling was performed at 0, 0.5, 1, 3, 6, 12, and 24 h post-dosing on day 20. We monitored LFT at baseline on days-1, 7, and 21 and sacrificed the rats on the last day of the experiment. RESULTS: ATT treatment sustained the CCl4-induced liver injury changes. A significant rise in mean total bilirubin levels was observed in groups administered rifampicin. The triple drug combination group demonstrated 1.43- and 1.84-times higher area-under-the-curve values of RMP (234.56±30.66 vs. 163.55±36.14 µg h/mL) and DARP (16.15±4.50 vs. 8.75±2.79 µg h/mL) compared to RMP alone group. Histological and oxidative stress changes supported underlying liver injury and PK alterations. CONCLUSIONS: RMP metabolism inhibition by PZA, more than isoniazid, was well preserved in the presence of underlying liver injury.

Bioactives from medicinal herb against bedaquiline resistant tuberculosis: removing the dark clouds from the horizon.

Tuberculosis is a contagious bacterial ailment that primarily affects the lungs and is brought on by the bacterium Mycobacterium tuberculosis (MTB). An antimycobacterial medication called bedaquiline (BQ) is specified to treat multidrug-resistant tuberculosis (MDR-TB). Despite its contemporary use in clinical practice, the mutations (D32 A/G/N/V/P) constrain the potential of BQ by causing transitions in the structural conformation of the atpE subunit-c after binding. In this study, we have taken the benzylisoquinoline alkaloids from thalictrum foliolosum due to its antimicrobial activity reported in prior literature. We used an efficient and optimized structure-based strategy to examine the wild type (WT) and mutated protein upon molecule binding. Our results emphasize the drastic decline in BQ binding affinity of mutant and WT atpE subunit-c complexes compared to thalirugidine (top hit) from thalictrum foliolosum. The decrease in BQ binding free energy is due to electrostatic energy because nearly every atom in a macromolecule harbors a partial charge, and molecules taking part in molecular recognition will interact electrostatically. Similarly, the high potential mean force of thalirugidine than BQ in WT and mutant complexes demonstrated the remarkable ability to eradicate mycobacteria efficiently. Furthermore, the Alamar blue cell viability and ATP determination assay were performed to validate the computational outcomes in search of novel antimycobacterial. Upon closer examination of the ATP determination assay, it became apparent that both BQ and thalirugidine showed similar reductions in ATP levels at their respective MICs, presenting a potential common mechanism of action.

Whole genome sequencing reveals candidate genes involving in PAS resistance in M. Tuberculosis isolated from patients in Thailand.

Para-amino salicylic acid (PAS) was first reported by Lehmann in 1946 and used for tuberculosis treatment. However, due to its adverse effects, it is now used only as a second line anti-tuberculosis drug for treatment of multidrug resistant or extensively drug resistant M. tuberculosis. The structure of PAS is similar to para-amino benzoic acid (pABA), an intermediate metabolite in the folate synthesis pathway. The study has identified mutations in genes in folate pathway and their intergenic regions for their possibilities in responsible for PAS resistance. Genomic DNA from 120 PAS-resistant and 49 PAS-sensitive M. tuberculosis isolated from tuberculosis patients in Thailand were studied by whole genome sequencing. Twelve genes in the folate synthesis pathway were investigated for variants associated with PAS resistance. Fifty-one SNVs were found in nine genes and their intergenic regions (pabC, pabB, folC, ribD, thyX, dfrA, thyA, folK, folP). Functional correlation test confirmed mutations in RibD, ThyX, and ThyA are responsible for PAS resistance. Detection of mutation in thyA, folC, intergenic regions of thyX, ribD, and double deletion of thyA dfrA are proposed for determination of PAS resistant M. tuberculosis.

Genomic revolution: Transforming tuberculosis diagnosis and treatment with the use of Whole Genome Sequencing - A consensus statement.

Tuberculosis (TB) is a preventable, treatable, and curable disease. However, in 2020, 9∙9 million people were estimated to have developed tuberculosis, and 1.5 million people were estimated to have died from it. Whereas in India, 2.6 million were diagnosed with TB and 436,000 succumbed to TB in 2019. India (26%) is the major contributor to the global drop in TB cases. The COVID-19 pandemic has substantially reduced access to services for the diagnosis and treatment of TB, resulting in an increase in deaths and a reversal in global progress. [1] Presently, TB incidence is falling at a rate of 2% per year, obstructed mainly by the rearing pandemic of drug-resistant tuberculosis (DRTB). Particularly concerning is multi-drug resistant TB (MDRTB), defined as resistance towards isoniazid (INH) and rifampicin (RIF). [2] The World Health Organization (WHO) targeted to reduce worldwide TB incidence by 90% until 2035. (1) Early initiation of effective treatment based on susceptibility patterns of the Mycobacterium tuberculosis complex (MTBC) is considered key to successful TB control in countries with high DRTB incidence. Worldwide MDRTB treatment outcomes are poor, with cure rates less than 60% (2) due to the lack of comprehensive Drug Susceptibility Testing (DST) in most high MDRTB burden countries. This is leading to the inadequate anti-TB activity of the provided regimens (3-5), unlike regimens advised for DST assure optimal results. (6) In addition to resistances to the established regimens, the resistance to the newer DRTB drugs is increasing. On World TB Day 2022, Academy of Advanced Medical Education, Thyrocare Technologies Limited and HyastackAnalytics - IITB along with expert pulmonologist and renowned physicians from India convened for an advisory board meeting in Delhi on 20th March 2022 to discuss the role of Whole Genome Sequencing (WGS) in the diagnosis and management of TB. Objectives and specific topics relating to WGS in MDRTB were discussed, each expert shared their views, which led to a group discussion with a commitment to putting the patient first, and increasing their collective efforts, the organizations recognized that it is possible to make this goal a reality. The organizations involved in the discussion have declared their commitment to engaging in collaborative efforts to tackle DRTB detection efficiently. They advocate for strengthening access to WGS TB services, controlling and preventing TB, improving surveillance and drug resistance management, and investing in research and development. This Round Table serves as a framework to build on and ensure that the goal of ending TB is achievable with WGS services wherever needed. Post discussion, a uniform consensus was said to be arrived if more than 80% board members agreed to the statement. The present paper is the outcome of aspects presented and discussed in the advisory board meeting.

Advanced drug delivery and therapeutic strategies for tuberculosis treatment.

Tuberculosis (TB) remains a significant global health challenge, necessitating innovative approaches for effective treatment. Conventional TB therapy encounters several limitations, including extended treatment duration, drug resistance, patient noncompliance, poor bioavailability, and suboptimal targeting. Advanced drug delivery strategies have emerged as a promising approach to address these challenges. They have the potential to enhance therapeutic outcomes and improve TB patient compliance by providing benefits such as multiple drug encapsulation, sustained release, targeted delivery, reduced dosing frequency, and minimal side effects. This review examines the current landscape of drug delivery strategies for effective TB management, specifically highlighting lipid nanoparticles, polymer nanoparticles, inorganic nanoparticles, emulsion-based systems, carbon nanotubes, graphene, and hydrogels as promising approaches. Furthermore, emerging therapeutic strategies like targeted therapy, long-acting therapeutics, extrapulmonary therapy, phototherapy, and immunotherapy are emphasized. The review also discusses the future trajectory and challenges of developing drug delivery systems for TB. In conclusion, nanomedicine has made substantial progress in addressing the challenges posed by conventional TB drugs. Moreover, by harnessing the unique targeting abilities, extended duration of action, and specificity of advanced therapeutics, innovative solutions are offered that have the potential to revolutionize TB therapy, thereby enhancing treatment outcomes and patient compliance.

[Update: Diagnostics and treatment of pulmonary tuberculosis]. / Update: Diagnostik und Therapie der pulmonalen Tuberkulose.

Molecular diagnostic tools have changed the approach to the detection of Mycobacterium tuberculosis and associated drug-resistance substantially. PCR-based technologies allow a more rapid detection with higher diagnostic sensitivity in pulmonary and extrapulmonary specimens. However, a real point of care test, which needs minimal technical resources remains missing. Genome sequencing technologies are currently changing tuberculosis drug resistance testing, and for some questions are replacing phenotypic drug resistance testing, based on culture.New evidence on treatment for drug-sensitive tuberculosis allows shortening of treatment to 4 months, or in selected cases even to 2 months based on the use of fluoroquinolones, high dose rifamycins and newly developed TB medicines.Such developments will very likely simplify the management of tuberculosis, although prevention remains the most important pillar of any tuberculosis related public health strategy.

Antimicrobial drug resistant features of Mycobacterium tuberculosis associated with treatment failure.

Tuberculosis stands as a prominent cause of mortality in developing countries. The treatment of tuberculosis involves a complex procedure requiring the administration of a panel of at least four antimicrobial drugs for the duration of six months. The occurrence of treatment failure after the completion of a standard treatment course presents a serious medical problem. The purpose of this study was to evaluate antimicrobial drug resistant features of Mycobacterium tuberculosis associated with treatment failure. Additionally, it aimed to evaluate the effectiveness of second line drugs such as amikacin, linezolid, moxifloxacin, and the efflux pump inhibitor verapamil against M. tuberculosis isolates associated with treatment failure. We monitored 1200 tuberculosis patients who visited TB centres in Lahore and found that 64 of them were not cured after six months of treatment. Among the M. tuberculosis isolates recovered from the sputum of these 64 patients, 46 (71.9%) isolates were simultaneously resistant to rifampicin and isoniazid (MDR), and 30 (46.9%) isolates were resistant to pyrazinamide, Resistance to amikacin was detected in 17 (26,5%) isolates whereas resistance to moxifloxacin and linezolid was detected in 1 (1.5%) and 2 (3.1%) isolates respectively. Among MDR isolates, the additional resistance to pyrazinamide, amikacin, and linezolid was detected in 15(23.4%), 4(2.6%) and 1(1.56%) isolates respectively. One isolate simultaneously resistant to rifampicin, isoniazid, amikacin, pyrazinamide, and linezolid was also identified. In our investigations, the most frequently mutated amino acid in the treatment failure group was Serine 315 in katG. Three novel mutations were detected at codons 99, 149 and 154 in pncA which were associated with pyrazinamide resistance. The effect of verapamil on the minimum inhibitory concentration of isoniazid and rifampicin was observed in drug susceptible isolates but not in drug resistant isolates. Rifampicin and isoniazid enhanced the transcription of the efflux pump gene rv1258 in drug susceptible isolates collected from the treatment failure patients. Our findings emphasize a high prevalence of MDR isolates linked primarily to drug exposure. Moreover, the use of amikacin as a second line drug may not be the most suitable choice in such cases.

Effect of seven anti-tuberculosis treatment regimens on sputum microbiome: a retrospective analysis of the HIGHRIF study 2 and PanACEA MAMS-TB clinical trials.

BACKGROUND: Respiratory tract microbiota has been described as the gatekeeper for respiratory health. We aimed to assess the impact of standard-of-care and experimental anti-tuberculosis treatment regimens on the respiratory microbiome and implications for treatment outcomes. METHODS: In this retrospective study, we analysed the sputum microbiome of participants with tuberculosis treated with six experimental regimens versus standard-of-care who were part of the HIGHRIF study 2 (NCT00760149) and PanACEA MAMS-TB (NCT01785186) clinical trials across a 3-month treatment follow-up period. Samples were from participants in Mbeya, Kilimanjaro, Bagamoyo, and Dar es Salaam, Tanzania. Experimental regimens were composed of different combinations of rifampicin (R), isoniazid (H), pyrazinamide (Z), ethambutol (E), moxifloxacin (M), and a new drug, SQ109 (Q). Reverse transcription was used to create complementary DNA for each participant's total sputum RNA and the V3-V4 region of the 16S rRNA gene was sequenced using the Illumina metagenomic technique. Qiime was used to analyse the amplicon sequence variants and estimate alpha diversity. Descriptive statistics were applied to assess differences in alpha diversity pre-treatment and post-treatment initiation and the effect of each treatment regimen. FINDINGS: Sequence data were obtained from 397 pre-treatment and post-treatment samples taken between Sept 26, 2008, and June 30, 2015, across seven treatment regimens. Pre-treatment microbiome (206 genera) was dominated by Firmicutes (2860 [44%] of 6500 amplicon sequence variants [ASVs]) at the phylum level and Streptococcus (2340 [36%] ASVs) at the genus level. Two regimens had a significant depressing effect on the microbiome after 2 weeks of treatment, HR20mg/kgZM (Shannon diversity index p=0·0041) and HR35mg/kgZE (p=0·027). Gram-negative bacteria were the most sensitive to bactericidal activity of treatment with the highest number of species suppressed being under the moxifloxacin regimen. By week 12 after treatment initiation, microbiomes had recovered to pre-treatment level except for the HR35mg/kgZE regimen and for genus Mycobacterium, which did not show recovery across all regimens. Tuberculosis culture conversion to negative by week 8 of treatment was associated with clearance of genus Neisseria, with a 98% reduction of the pre-treatment level. INTERPRETATION: HR20mg/kgZM was effective against tuberculosis without limiting microbiome recovery, which implies a shorter efficacious anti-tuberculosis regimen with improved treatment outcomes might be achieved without harming the commensal microbiota. FUNDING: European and Developing Countries Clinical Trials Partnership and German Ministry of Education and Research.