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Introduction: Tuberculosis (TB) is one of the most prevalent infectious diseases globally, often presenting with nonspecific symptoms that can obscure diagnosis, especially when it manifests in uncommon sites such as osteoarticular tuberculosis (OA-TB). Case presentation: We report a rare case of a 9-year-old male diagnosed with right knee tuberculosis after enduring severe symptoms for several months. Despite multiple negative biopsies and aspirates during initial debridement surgeries, a biopsy taken 6 months later confirmed the presence of Mycobacterium tuberculosis (MTB). The patient was subsequently treated with debridement and anti-tubercular therapy. Conclusion: This case underscores the critical need to consider tuberculosis in patients presenting with chronic bone pain to avoid misdiagnosis, particularly in the developing world. The atypical presentation of osteoarticular tuberculosis in this young patient emphasizes the need for healthcare professionals to recognize subtle symptoms. Advanced imaging studies like MRI and microbiological evaluations, including site biopsies, are essential for accurate diagnosis. Increased awareness and collaborative research are crucial to improving the understanding and management of pediatric osteoarticular tuberculosis and extrapulmonary tuberculosis. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) is a serious disease that has been observed since ancient times. In the mid-to late20th century, the main clinical approach to this disease involved focusing on its diagnosis, prevention, and treatment. However, in the 21st century, the focus has shifted toward the diagnosis and treatment of drug-resistant TB. With the use of the Xpert MTB/RIF assay at the frontlines in India, interpreting indeterminate results to treatment with rifampicin, an antitubercular drug, can be challenging. This is further exacerbated by a lack of knowledge regarding mutation frequency in antitubercular drugresistant genes in this region. Among antitubercular drugs, rifampicin is the most potent and effective drug for the treatment of tuberculosis; hence, understanding the pattern of rifampicin resistance (rpoB) gene mutations will provide insights into the genetic basis of this resistance, which may help in the prevention and treatment of TB. This retrospective observational study presents sociodemographic details, sample types, Mycobacterium tuberculosis load, types of probe mutations detected, and rifampicin indeterminate results from the Xpert MTB/RIF assay. Of the 314 samples analyzed, 258 showed rifampicin resistance as detected by MTB, with 56 samples of MTB-detected rifampicin indeterminate results. Type E probe mutation (58.9%) was the most common type, while the least frequent mutation was Type C probe (1.5%). No missing probe was observed in approximately 8.9% of samples. Among the 56 rifampicin indeterminate results, the maximum Cycle threshold value did not cross 34.5 in six samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • Antitubercular potential of Halosarcia indica (Willd.) was determined for the first time. • SF3K fraction was observed to be most potent fraction with a MIC of ≤ 3.125 µg/mL. • H. indica bioactive fraction was found non-toxic against Vero cell line. Tuberculosis (TB) is one of the oldest leading health diseases of mankind, caused by the bacteria Mycobacterium tuberculosis. It is still the major cause of high mortality and morbidity worldwide from a single infectious agent. Plant species belonging to the genus Halosarcia (formerly known as Salicornia) are known for their various medicinal properties like antioxidant, hepatoprotective, immunomodulatory, antimicrobial, etc., but not evaluated for their antimycobacterial property. The present study aimed to investigate the potential of Halosarcia indica (Willd.) (formerly known as Salicornia brachiata Roxb.), a halophytic plant, a source of antitubercular agents. The study involved the preparation of various extracts from different parts of the plant and the evaluation of their inhibitory activities against Mycobacterium tuberculosis H37Rv using in vitro and in vivo assays. It was observed that the aqueous extract of the roots had the highest anti-TB activity with minimum inhibitory concentration (MIC) of 50 µg/mL and a ten-fold reduction of M. tuberculosis bacilli in the lungs of treated mice. Further fractionation of aqueous extract of roots using butanol, MeOH:CHCl 3 , MeOH, MeOH:H 2 O, and H 2 O yielded fractions with varying anti-TB activity. The subfraction SF3K obtained from fraction 2 (F-2) showed the highest potency, with MIC ≤ 3.125 µg/mL and an increase of 5 days in the mean survival time of M. tuberculosis-infected and treated (with SF3K) mice. This subfraction was found to be non-cytotoxic (in vitro) and non-toxic (during in vivo efficacy evaluation). The present study, for the first time, provides scientific evidence for the use of H. indica in the treatment of tuberculosis. [ABSTRACT FROM AUTHOR]

To analyze the results of proficiency testing for anti-tuberculosis drug susceptibility testing (DST) in China. Number of laboratory participating the proficiency testing performed DST, and the sensitivity, specificity, reproducibility, and accordance rate were calculated from data of 13 rounds proficiency testing results for DST from 2008 to 2021. A total of 30 and 20 strains of Mycobacterium tuberculosis with known susceptibility results were sent to each laboratory in 2008 to 2019, 2020 and 2021, respectively. The number of participating laboratories ranged from 30 in 2009 to 546 in 2021. L-J DST was the predominant method. The specificity presented relatively higher than sensitivity. Improvement of specificity were observed for all drugs through the years, while sensitivity did not show improvement for amikacin and capreomycin. Accordance rate of pyrazinamide and kanamycin and reproducibility of capreomycin and pyrazinamide were not significantly improved through the years. Most of the participating laboratories significantly improved the quality of their DST through the consecutive rounds of proficiency testing except for second-line injectable drugs and pyrazinamide. The results highlight the importance of developing novel and/or improving existing methods for phenotypic DST for certain drugs. [ABSTRACT FROM AUTHOR]

Background: Tuberculosis (TB) represents a major global health challenge. Drug resistance in Mycobacterium tuberculosis (MTB) poses a substantial obstacle to effective TB treatment. Identifying genomic mutations in MTB isolates holds promise for unraveling the underlying mechanisms of drug resistance in this bacterium. Methods: In this study, we investigated the roles of single nucleotide variants (SNVs) in MTB isolates resistant to four antibiotics (moxifloxacin, ofloxacin, amikacin, and capreomycin) through whole-genome analysis. We identified the drug-resistance-associated SNVs by comparing the genomes of MTB isolates with reference genomes using the MuMmer4 tool. Results: We observed a strikingly high proportion (94.2%) of MTB isolates resistant to ofloxacin, underscoring the current prevalence of drug resistance in MTB. An average of 3529 SNVs were detected in a single ofloxacin-resistant isolate, indicating a mutation rate of approximately 0.08% under the selective pressure of ofloxacin exposure. We identified a set of 60 SNVs associated with extensively drug-resistant tuberculosis (XDR-TB), among which 42 SNVs were non-synonymous mutations located in the coding regions of nine key genes (ctpI, desA3, mce1R, moeB1, ndhA, PE_PGRS4, PPE18, rpsA, secF). Protein structure modeling revealed that SNVs of three genes (PE_PGRS4, desA3, secF) are close to the critical catalytic active sites in the three-dimensional structure of the coding proteins. Conclusion: This comprehensive study elucidates novel resistance mechanisms in MTB against antibiotics, paving the way for future design and development of anti-tuberculosis drugs. [ABSTRACT FROM AUTHOR]

Background The duration of the protective effect of tuberculosis preventive therapy (TPT) is controversial. Some studies have found that the protective effect of TPT is lost after cessation of therapy among people with human immunodeficiency virus (HIV) in settings with very high tuberculosis incidence, but others have found long-term protection in low-incidence settings. Methods We estimated the incidence rate (IR) of new tuberculosis disease for up to 12 years after randomization to 4 months of rifampin or 9 months of isoniazid, among 991 Brazilian participants in a TPT trial in the state of Rio de Janeiro, with an incidence of 68.6/100 000 population in 2022. The adjusted hazard ratios (aHRs) of independent variables for incident tuberculosis were calculated. Results The overall tuberculosis IR was 1.7 (95% confidence interval [CI], 1.01– 2.7) per 1000 person-years (PY). The tuberculosis IR was higher among those who did not complete TPT than in those who did (2.9 [95% CI, 1.3–5.6] vs 1.1 [.4–2.3] per 1000 PY; IR ratio, 2.7 [1.0–7.2]). The tuberculosis IR was higher within 28 months after randomization (IR, 3.5 [95% CI, 1.6–6.6] vs 1.1 [.5–2.1] per 1000 PY between 28 and 143 months; IR ratio, 3.1 [1.2–8.2]). Treatment noncompletion was the only variable associated with incident tuberculosis (aHR, 3.2 [95% CI, 1.1–9.7]). Conclusions In a mostly HIV-noninfected population, a complete course of TPT conferred long-term protection against tuberculosis. [ABSTRACT FROM AUTHOR]

Tuberculosis is the second leading infectious killer after coronavirus disease 2019 (COVID-19). Standard antitubercular drugs exhibit various limitations like toxicity, long treatment regimens, and lack of effect against dormant and drug-resistant organisms. Here, we report that all- trans -retinoic acid (ATRA) improves Mycobacterium tuberculosis clearance in mice during treatment with the antitubercular drug isoniazid. Interestingly, ATRA promoted activities of lysosomes and mitochondria, and production of various inflammatory mediators in macrophages. Furthermore, ATRA upregulated the expression of genes of lipid metabolism pathways in macrophages. We demonstrated that ATRA activated the MEK/ERK pathway in macrophages in vitro and MEK/ERK and p38 MAPK pathways in mice. Finally, ATRA induced both Th1 and Th17 responses in lungs and spleens of M. tuberculosis -infected mice. Together, these data indicate that ATRA provides beneficial adjunct therapeutic value by modulating MEK/ERK and p38 MAPK pathways and thus warrants further testing for human use. [ABSTRACT FROM AUTHOR]

A series of novel 2,3,5‐trisubstituted thiazolidinone derivatives was designed and synthesized. Compounds were tested for their antimicrobial and antitubercular activities. Compounds 3‐(2,4‐difluorobenzyl)‐5‐[(5‐methylfuran‐2‐yl)methylidene]‐2‐(phenylimino)‐1,3‐thiazolidin‐4‐one (5 c) and 3‐(2,4‐difluorobenzyl)‐2‐((3‐fluorophenyl)imino)‐5‐((Z)‐4‐hydroxybenzylidene) thiazolidin‐4‐one (6 f) exhibited remarkable antimicrobial activity against Klebsiella pneumoniae and Escherichia coli respectively. All compounds except 3‐(2,4‐difluorobenzyl)‐5‐((3‐(4‐fluorophenyl)‐1‐phenyl‐1H‐pyrazol‐4‐yl)methylene)‐2‐(phenylimino)thiazolidin‐4‐one (5 a) and (6 f) exposed excellent antitubercular activity in comparison with the standard drugs against H37RV strain of Mycobacterium tuberculosis (ATCC No‐ 27294). In addition, molecular docking and dynamic simulations studies were performed with E. coli Mur B (EMB) (PDB ID: 2Q85), Aspergillus fumigatus sterol 14‐alpha demethylase (ASD) (PDB ID: 4UYM) and Mycobacterium tuberculosis pantothenate synthetase (MPS) (PDB ID: 3IVX) proteins against all compounds and the most potent compound (5 c) displayed higher binding proficiency. These compounds may serve as lead compounds for further optimization to achieve promising therapeutic properties. [ABSTRACT FROM AUTHOR]

Targeting translation factor proteins holds promise for developing innovative anti-tuberculosis drugs. During protein translation, many factors cause ribosomes to stall at messenger RNA (mRNA). To maintain protein homeostasis, bacteria have evolved various ribosome rescue mechanisms, including the predominant trans-translation process, to release stalled ribosomes and remove aberrant mRNAs. The rescue systems require the participation of translation elongation factor proteins (EFs) and are essential for bacterial physiology and reproduction. However, they disappear during eukaryotic evolution, which makes the essential proteins and translation elongation factors promising antimicrobial drug targets. Here, we review the structural and molecular mechanisms of the translation elongation factors EF-Tu, EF-Ts, and EF-G, which play essential roles in the normal translation and ribosome rescue mechanisms of Mycobacterium tuberculosis (Mtb). We also briefly describe the structure-based, computer-assisted study of anti-tuberculosis drugs. [ABSTRACT FROM AUTHOR]

Mycobacterium tuberculosis remains the most common infectious killer worldwide despite decades of antitubercular drug development. Effectively controlling the tuberculosis (TB) pandemic will require innovation in drug discovery. In this review, we provide a brief overview of the two main approaches to discovering new TB drugs—phenotypic screens and target‐based drug discovery—and outline some of the limitations of each method. We then explore recent advances in genetic tools that aim to overcome some of these limitations. In particular, we highlight a novel metric to prioritize essential targets, termed vulnerability. Stratifying targets based on their vulnerability presents new opportunities for future target‐based drug discovery campaigns. [ABSTRACT FROM AUTHOR]

Host-directed therapies (HDTs) represent an emerging approach for bacterial clearance during tuberculosis (TB) infection. While most HDTs are designed and implemented for immuno-modulation, other host targets-such as nonimmune stromal components found in pulmonary granulomas-may prove equally viable. Building on our previous work characterizing and normalizing the aberrant granuloma-associated vasculature, here we demonstrate that FDA-approved therapies (bevacizumab and losartan, respectively) can be repurposed as HDTs to normalize blood vessels and extracellular matrix (ECM), improve drug delivery, and reduce bacterial loads in TB granulomas. Granulomas feature an overabundance of ECM and compressed blood vessels, both of which are effectively reduced by losartan treatment in the rabbit model of TB. Combining both HDTs promotes secretion of proinflammatory cytokines and improves anti-TB drug delivery. Finally, alone and in combination with second-line antitubercular agents (moxifloxacin or bedaquiline), these HDTs significantly reduce bacterial burden. RNA sequencing analysis of HDT-treated lung and granuloma tissues implicates up-regulated antimicrobial peptide and proinflammatory gene expression by ciliated epithelial airway cells as a putative mechanism of the observed antitubercular benefits in the absence of chemotherapy. These findings demonstrate that bevacizumab and losartan are well-tolerated stroma-targeting HDTs, normalize the granuloma microenvironment, and improve TB outcomes, providing the rationale to clinically test this combination in TB patients. [ABSTRACT FROM AUTHOR]

A thorough search for the development of innovative drugs to treat tuberculosis, especially considering the urgent need to address developing drug resistance, we report here a synthetic series of ethyl 3‐benzoyl‐7‐morpholinoindolizine‐1‐carboxylate analogues (5a‐o) as potent anti‐tubercular agents. These morpholino‐indolizines were synthesized by reacting 4‐morpholino pyridinium salts, with various electron‐deficient acetylenes to afford the ethyl 3‐benzoyl‐7‐morpholinoindolizine‐1‐carboxylate analogues (5a‐o). All synthesized intermediate and final compounds are characterized by spectroscopic methods such as 1H NMR, 13C NMR and HRMS and further examined for their anti‐tubercular activity against the M. tuberculosis H37Rv strain (ATCC 27294—American type cell culture). All the compounds screened for anti‐tubercular activity in the range of 6.25–50 μM against the H37Rv strain of Mycobacterium tuberculosis. Compound 5g showed prominent activity with MIC99 2.55 μg/mL whereas compounds 5d and 5j showed activity with MIC99 18.91 μg/mL and 25.07 μg/mL, respectively. In silico analysis of these compounds revealed drug‐likeness. Additionally, the molecular target identification for Malate synthase (PDB 5CBB) is attained by computational approach. The compound 5g with a MIC99 value of 2.55 μg/mL against M. tuberculosis H37Rv emerged as the most promising anti‐TB drug and in silico investigations suggest Malate synthase (5CBB) might be the compound's possible target. [ABSTRACT FROM AUTHOR]

The present work describes the unrevealed potential of tetrahydropyridines as anticancer and anti-tubercular agents along with DFT, ADMET, drug-likeliness and molecular docking studies synthesized by using Bronsted acidic ionic liquid viz. 1-methyl-3-(4-sulfobutyl)-1H-imidazol-3-ium chloride [MSbIM-Cl]. The synthesized derivatives have been screened for their anticancer and anti-tubercular evaluation against MCF-7 cell lines and Mycobacterium tuberculosis respectively. The compound 4e showed the highest anticancer activity while the compound 4h showed the highest anti-tubercular activity. The in vitro evaluation has been supported by computational methods such as molecular docking, density functional study and in silico ADMET and drug-likeliness prediction. [ABSTRACT FROM AUTHOR]

Trends in and risk factors for drug resistance in Mycobacterium tuberculosis (M. tuberculosis) in human immunodeficiency virus (HIV)-infected patients with active tuberculosis were analyzed. The clinical data of M. tuberculosis and HIV-coinfected patients treated at the Shanghai Public Health Clinical Center between 2010 and 2022 were collected. The diagnosis of tuberculosis was confirmed by solid or liquid culture. The phenotypic drug susceptibility test was carried out via the proportional method, and the resistance to first-line and second-line drugs was analyzed. Logistic regression analysis was performed to identify associated risk factors for drug resistance in M. tuberculosis. Of the 304 patients with a M. tuberculosis-positive culture and first-line drug susceptibility test results, 114 (37.5%) were resistant to at least one first-line anti-tuberculosis drug. Of the 93 patients with first-line and second-line drug susceptibility test results, 40 (43%) were resistant to at least one anti-tuberculosis drug, and 20 (21.5%), 27 (29.0%), 19 (20.4%), 16 (17.2%), and 14 (15.1%) were resistant to rifampicin, streptomycin, ofloxacin, levofloxacin, and moxifloxacin, respectively; 17 patients (18.3%) had multidrug-resistant tuberculosis (MDR-TB). Between 2010 and 2021, the rate of resistance to streptomycin and rifampicin ranged from 14.3% to 40.0% and from 8.0% to 26.3%, respectively, showing an increasing trend year by year. From 2016 to 2021, the rate of resistance to quinolones fluctuated between 7.7% and 27.8%, exhibiting an overall upward trend. Logistic regression analysis showed that being aged <60 years old was a risk factor for streptomycin resistance, mono-drug resistance, and any-drug resistance (RR 4.139, p = 0.023; RR 7.734, p = 0.047; RR 3.733, p = 0.009). Retreatment tuberculosis was a risk factor for resistance to rifampicin, ofloxacin, of levofloxacin (RR 2.984, p = 0.047; RR 4.517, p = 0.038; RR 6.277, p = 0.014). The drug resistance rates of M. tuberculosis to rifampicin and to quinolones in HIV/AIDS patients were high and have been increasing year by year. Age and a history of previous anti-tuberculosis treatment were the main factors associated with the development of drug resistance in HIV/AIDS patients with tuberculosis. [ABSTRACT FROM AUTHOR]

New drugs are needed to shorten and simplify treatment of tuberculosis caused by Mycobacterium tuberculosis. Metabolic pathways that M. tuberculosis requires for growth or survival during infection represent potential targets for anti-tubercular drug development. Genes and metabolic pathways essential for M. tuberculosis growth in standard laboratory culture conditions have been defined by genome-wide genetic screens. However, whether M. tuberculosis requires these essential genes during infection has not been comprehensively explored because mutant strains cannot be generated using standard methods. Here we show that M. tuberculosis requires the phenylalanine (Phe) and de novo purine and thiamine biosynthetic pathways for mammalian infection. We used a defined collection of M. tuberculosis transposon (Tn) mutants in essential genes, which we generated using a custom nutrient-rich medium, and transposon sequencing (Tn-seq) to identify multiple central metabolic pathways required for fitness in a mouse infection model. We confirmed by individual retesting and complementation that mutations in pheA (Phe biosynthesis) or purF (purine and thiamine biosynthesis) cause death of M. tuberculosis in the absence of nutrient supplementation in vitro and strong attenuation in infected mice. Our findings show that Tn-seq with defined Tn mutant pools can be used to identify M. tuberculosis genes required during mouse lung infection. Our results also demonstrate that M. tuberculosis requires Phe and purine/thiamine biosynthesis for survival in the host, implicating these metabolic pathways as prime targets for the development of new antibiotics to combat tuberculosis. Author summary: Mycobacterium tuberculosis causes more than 10 million new cases of active tuberculosis (TB) disease and ~1.3 million deaths worldwide each year. Individuals with active TB must take a combination of four antibiotics for a minimum of 6–9 months to cure the infection. New anti-tubercular drugs are needed to simplify TB treatment and combat drug resistance. Here, we describe a novel collection of M. tuberculosis mutants lacking metabolic pathways essential for growth in standard laboratory conditions. Using these mutants, a mouse infection model, and deep sequencing we identified those metabolic pathways that M. tuberculosis also requires during infection. We find that M. tuberculosis mutants that cannot synthesize purine nucleotides, riboflavin, or certain amino acids are unable to grow in mice. We also find that mutant strains which cannot synthesize purine nucleotides or the amino acid phenylalanine die rapidly in laboratory cultures without nutrient supplementation, suggesting that new drugs targeting these pathways would kill M. tuberculosis. Overall, our work reveals multiple metabolic pathways that M. tuberculosis requires during infection, which could be pursued as new targets for development of anti-tubercular drugs. [ABSTRACT FROM AUTHOR]

α-Methylacyl-CoA racemase in M. tuberculosis (MCR) has an essential role in fatty acid metabolism and cholesterol utilization, contributing to the bacterium's survival and persistence. Understanding the enzymatic activity and structural features of MCR provides insights into its physiological and pathological significance and potential as a therapeutic target. Here, we report high-resolution crystal structures for wild-type MCR in a new crystal form (at 1.65 Å resolution) and for three active-site mutants, H126A, D156A and E241A, at 2.45, 1.64 and 1.85 Å resolutions, respectively. Our analysis of the new wild-type structure revealed a similar dimeric arrangement of MCR molecules to that previously reported and details of the catalytic site. The determination of the structures of these H126A, D156A and E241A mutants, along with their detailed kinetic analysis, has now allowed for a rigorous assessment of their catalytic properties. No significant change outside the enzymatic active site was observed in the three mutants, establishing that the diminution of catalytic activity is mainly attributable to disruption of the catalytic apparatus involving key hydrogen bonding and water-mediated interactions. The wild-type structure, together with detailed mutational and biochemical data, provide a basis for understanding the catalytic properties of this enzyme, which is important for the design of future anti-tuberculosis drug molecules. [ABSTRACT FROM AUTHOR]

Low‐molecular‐weight (LMW) thiols are involved in many processes in all organisms, playing a protective role against reactive species, heavy metals, toxins and antibiotics. Actinobacteria, such as Mycobacterium tuberculosis, use the LMW thiol mycothiol (MSH) to buffer the intracellular redox environment. The NADPH‐dependent FAD‐containing oxidoreductase mycothiol disulfide reductase (Mtr) is known to reduce oxidized mycothiol disulfide (MSSM) to MSH, which is crucial to maintain the cellular redox balance. In this work, the first crystal structures of Mtr are presented, expanding the structural knowledge and understanding of LMW thiol reductases. The structural analyses and docking calculations provide insight into the nature of Mtrs, with regard to the binding and reduction of the MSSM substrate, in the context of related oxidoreductases. The putative binding site for MSSM suggests a similar binding to that described for the homologous glutathione reductase and its respective substrate glutathione disulfide, but with distinct structural differences shaped to fit the bulkier MSSM substrate, assigning Mtrs as uniquely functioning reductases. As MSH has been acknowledged as an attractive antitubercular target, the structural findings presented in this work may contribute towards future antituberculosis drug development. [ABSTRACT FROM AUTHOR]

Targeting translational factor proteins (TFPs) presents significant promise for the development of innovative antitubercular drugs. Previous insights from antibiotic binding mechanisms and recently solved 3D crystal structures of Mycobacterium tuberculosis (Mtb) elongation factor thermo unstable–GDP (EF-Tu–GDP), elongation factor thermo stable–EF-Tu (EF-Ts–EF-Tu), and elongation factor G–GDP (EF-G–GDP) have opened up new avenues for the design and development of potent antituberculosis (anti-TB) therapies. [ABSTRACT FROM AUTHOR]

The bacterial determinants that facilitate Mycobacterium tuberculosis (Mtb) adaptation to the human host environment are poorly characterized. We have sought to decipher the pressures facing the bacterium in vivo by assessing Mtb genes that are under positive selection in clinical isolates. One of the strongest targets of selection in the Mtb genome is lldD2, which encodes a quinone-dependent L-lactate dehydrogenase (LldD2) that catalyzes the oxidation of lactate to pyruvate. Lactate accumulation is a salient feature of the intracellular environment during infection and lldD2 is essential for Mtb growth in macrophages. We determined the extent of lldD2 variation across a set of global clinical isolates and defined how prevalent mutations modulate Mtb fitness. We show the stepwise nature of lldD2 evolution that occurs as a result of ongoing lldD2 selection in the background of ancestral lineage-defining mutations and demonstrate that the genetic evolution of lldD2 additively augments Mtb growth in lactate. Using quinone-dependent antibiotic susceptibility as a functional reporter, we also find that the evolved lldD2 mutations functionally increase the quinone-dependent activity of LldD2. Using 13C-lactate metabolic flux tracing, we find that lldD2 is necessary for robust incorporation of lactate into central carbon metabolism. In the absence of lldD2, label preferentially accumulates in dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G3P) and is associated with a discernible growth defect, providing experimental evidence for accrued lactate toxicity via the deleterious buildup of sugar phosphates. The evolved lldD2 variants increase lactate incorporation to pyruvate while altering triose phosphate flux, suggesting both an anaplerotic and detoxification benefit to lldD2 evolution. We further show that the mycobacterial cell is transcriptionally sensitive to the changes associated with altered lldD2 activity which affect the expression of genes involved in cell wall lipid metabolism and the ESX- 1 virulence system. Together, these data illustrate a multifunctional role of LldD2 that provides context for the selective advantage of lldD2 mutations in adapting to host stress. Author summary: Mycobacterium tuberculosis (Mtb) is the causative agent of the deadly disease tuberculosis (TB). Mtb has infected humans for thousands of years, and over the millennia has adapted to circumvent the challenges presented by the human host. Characterizing how Mtb has evolved to contend with host pressure can improve our understanding of mechanisms that modulate bacterial fitness, which we can ultimately leverage to design better antitubercular agents and diagnostics. One way to assess ways in which Mtb is adapting to host stress is to characterize bacterial genes that are diversifying in patients. Here we focus on the gene lldD2, and we illustrate the stepwise acquisition of lldD2 mutations throughout Mtb evolutionary history. LldD2 mediates the metabolism of lactate, which is an abundant carbon source during infection. We show that both ancient and contemporary lldD2 mutations increase the ability of Mtb to grow in the presence of lactate, and these mutations have an additive effect. In addition, lldD2 mutations mitigate potential toxicity caused by lactate metabolism and also modulate the expression of genes that are involved in pathogenesis. In all, our data suggests that lactate is a long-standing host pressure and that Mtb adaption has ranging effects that augment bacterial fitness. [ABSTRACT FROM AUTHOR]

We studied the possibility of using 4-hexylresorcinol to increase the efficiency of anti-mycobacterial chemotherapy. In an in vitro experiment, 4-hexylresorcinol increased the efficiency of rifampicin, kanamycin, and isoniazid against Mycobacterium smegmatis by 3-5 times. Experiments in sanitation of BALB/c mice infected with M. smegmatis showed the best efficacy of the isoniazid and 4-hexylresorcinol combination in comparison with isoniazid monotherapy. The growth-inhibiting activity of the combination of antibiotic rifabutin with 4-hexylresorcinol was shown on 6 strains of M. tuberculosis. A 2-fold decrease in the minimum inhibitory concentration of this antibiotic in the presence of half-minimum inhibitory concentration of 4-hexylresorcinol was demonstrated for monoresistant strain M. tuberculosis 5360/42Hr. On the mouse model of experimental tuberculosis caused by M. tuberculosis H37Rv, a 5-fold decrease in lung contamination and more rapid complete cure were achieved in animals treated with the combination of rifabutin and 4-hexylresorcinol in comparison with rifabutin monotherapy. [ABSTRACT FROM AUTHOR]

Context: Mycobacterial membrane proteins Large 3 (MmpL3) is responsible for the transport of mycobacterial acids out of cell membrane to form cell wall, which is essential for the survival of Mycobacterium tuberculosis (Mtb) and has become a potent anti-tuberculosis target. SQ109 is an ethambutol (EMB) analogue, as a novel anti-tuberculosis drug, can effectively inhibit MmpL3, and has completed phase 2b-3 clinical trials. Drug resistance has always been the bottleneck problem in clinical treatment of tuberculosis. The S288T mutant of MmpL3 shows significant resistance to the inhibitor SQ109, while the specific action mechanism remains unclear. The results show that MmpL3 S288T mutation causes local conformational change with little effect on the global structure. With MmpL3 bound by SQ109 inhibitor, the distance between D710 and R715 increases resulting in H-bond destruction, but their interactions and proton transfer function are still restored. In addition, the rotation of Y44 in the S288T mutant leads to an obvious bend in the periplasmic domain channel and an increased number of contact residues, reducing substrate transport efficiency. This work not only provides a possible dual drug resistance mechanism of MmpL3 S288T mutant but also aids the development of novel anti-tuberculosis inhibitors. Methods: In this work, molecular dynamics (MD) and quantum mechanics (QM) simulations both were performed to compare inhibitor (i.e., SQ109) recognition, motion characteristics, and H-bond energy change of MmpL3 after S288T mutation. In addition, the WT_SQ109 complex structure was obtained by molecular docking program (Autodock 4.2); Molecular Mechanics/ Poisson Boltzmann Surface Area (MM-PBSA) and Solvated Interaction Energy (SIE) methods were used to calculate the binding free energies (∆Gbind); Geometric criteria were used to analyze the changes of hydrogen bond networks. [ABSTRACT FROM AUTHOR]

N, N-disubstituted glycosylated ureas have been synthesized in good-to-excellent yields by 1,4-conjugate addition of amines to glycosylated olefinic esters followed by reaction of resulting glycosyl β-amino esters with diisocyanates. The developed sugar-based molecules were well characterized by extensive standard spectroscopic analysis including NMR (1H, 13C, and DEPT), IR, MS, and elemental analysis and were screened for their biological activity against Mycobacterium tuberculosis (M. Tb.), where some of them displayed potent antitubercular activity. The molecules have been designed keeping in view the well-known inhibitors of the enzymes involved in the biosynthesis of mycobacterial cell wall polymers and may be further explored as lead molecules for the successful development of a potential antitubercular drug candidate. Dedicated to Dr. Rama P. Tripathi, Former Chief Scientist at CSIR-Central Drug Research Institute, Lucknow, India, for his extraordinary contribution to "Drug development against Tuberculosis" [ABSTRACT FROM AUTHOR]

Mycobacterium tuberculosis, a major cause of mortality from a single infectious agent, possesses a remarkable mycobacterial cell envelope. Penicillin-Binding Proteins (PBPs) are a family of bacterial enzymes involved in the biosynthesis of peptidoglycan. PBP4 (DacB) from M. tuberculosis (MtbPBP4) has been known to function as a carboxypeptidase, and the role and significance of carboxypeptidases as targets for anti-tuberculosis drugs or antibiotics have been extensively investigated over the past decade. However, their precise involvement remains incompletely understood. In this study, we employed predictive modeling and analyzed the three-dimensional structure of MtbPBP4. Interestingly, MtbPBP4 displayed a distinct domain structure compared to its homologs. Docking studies with meropenem verified the presence of active site residues conserved in PBPs. These findings establish a structural foundation for comprehending the molecular function of MtbPBP4 and offer a platform for the exploration of novel antibiotics. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Purpose: We aimed at evaluating the diagnostic efficacy of a nucleotide matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF–MS) assay to detect drug resistance of Mycobacterium tuberculosis. Methods: Overall, 263 M. tuberculosis clinical isolates were selected to evaluate the performance of nucleic MALDI-TOF–MS for rifampin (RIF), isoniazid (INH), ethambutol (EMB), moxifloxacin (MXF), streptomycin (SM), and pyrazinamide (PZA) resistance detection. The results for RIF, INH, EMB, and MXF were compared with phenotypic microbroth dilution drug susceptibility testing (DST) and whole-genome sequencing (WGS), and the results for SM and PZA were compared with those obtained by WGS. Results: Using DST as the gold standard, the sensitivity, specificity, and kappa values of the MALDI-TOF–MS assay for the detection of resistance were 98.2%, 98.7%, and 0.97 for RIF; 92.8%, 99%, and 0.90 for INH; 82.4%, 98.0%, and 0.82 for EMB; and 92.6%, 99.5%, and 0.94 for MXF, respectively. Compared with WGS as the reference standard, the sensitivity, specificity, and kappa values of the MALDI-TOF–MS assay for the detection of resistance were 97.4%, 100.0%, and 0.98 for RIF; 98.7%, 92.9%, and 0.92 for INH; 96.3%, 100.0%, and 0.98 for EMB; 98.1%, 100.0%, and 0.99 for MXF; 98.0%, 100.0%, and 0.98 for SM; and 50.0%, 100.0%, and 0.65 for PZA. Conclusion: The nucleotide MALDI-TOF–MS assay yielded highly consistent results compared to DST and WGS, suggesting that it is a promising tool for the rapid detection of sensitivity to RIF, INH, EMB, and MXF. [ABSTRACT FROM AUTHOR]

Background: Genitourinary Tuberculosis (GUTB) is a common site of extrapulmonary tuberculosis. The disease involves the kidneys, ureters, bladder, or genital organs. Clinical symptoms develop 10 - 15 years after primary infection. Only one-quarter of patients with GUTB have a known history of TB and about half of these patients have chest radiography findings. The current study aimed to determine the effects of GUTB. Methods: The included patients were successive cases with a diagnosis of genitourinary tuberculosis. A total of 62 cases were reported with the diagnosis of genitourinary tuberculosis. PCR for MTb was done in 37 cases. Radiological evaluation included chest X-ray, KUB in all cases, and intravenous urogram when serum creatinine was normal. FNAC was performed in cases with serosal masses. All patients received antitubercular drug therapy with 4 drugs (Rifampicin, Ethambutol, Isoniazid, and Pyrazinamide) for 2 months followed by 2 drugs (Rifampicin and Isoniazid) for 7 months. Results: Positive AFB staining and positive MTb culture in urine were seen in 31.37% and 41.17% of cases, respectively, confirming the presence of Mycobacterium tuberculosis in some GUTB patients. Positive PCR for MTb in urine is present in 67.56% of cases (in a subset of 37 patients). MTb culture in pus is only observed in 4 out of 7 cases, suggesting its less frequent occurrence compared to other positive findings. Sterile urine is found in 78.95% of cases, and Radiological abnormalities (IVU/NCCT/MUCG) suggestive of GUTB was found in 46/57 (80.7%) cases. Bladder biopsy was positive in 12/25(48%) cases done. A comparison of urinary PCR with urine for AFB staining urine for MTb culture and bladder biopsy was done. Conclusion: The urinary (PCR) stands out as the most sensitive indicator among all microbiological tests. When coupled with radiological abnormalities, it significantly expedites the diagnosis of genitourinary tuberculosis. Optimal treatment involves a combination of multidrug chemotherapy and judicious surgery, as necessary. It is highly advisable to make every effort to reconstruct the urinary tract due to the rewarding outcomes associated with this approach. However, in cases where tissue is infected and irreparably damaged, the most effective course of action is ablating the affected tissue. [ABSTRACT FROM AUTHOR]

The outer mycomembrane of Mycobacterium tuberculosis and related pathogens is a robust permeability barrier that protects against antibiotic treatment. Here, we demonstrate that synthetic analogues of the mycomembrane biosynthetic precursor trehalose monomycolate bearing truncated lipid chains increase permeability of Mycobacterium smegmatis cells and sensitize them to treatment with the first-line anti-tubercular drug rifampicin. The reported strategy may be useful for enhancing entry of drugs and other molecules to mycobacterial cells, and represents a new way to study mycomembrane structure and function. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) is a significant public health challenge, especially in developing nations. Developing a TB eradication strategy is hampered by the global health concern of drug-resistant (DR) TB. Effective patient treatment, preventing TB transfer and avoiding the upsurge of DR strains depend primarily on the timely and accurate identification of DR TB. Due to inadequate sensitivity, the necessity of trained laboratory personnel, the sluggish growth pattern of Mycobacterium bacilli in culture, and the small number of bacilli that are usually found in extrapulmonary TB samples, TB diagnosis is still tricky in clinical practice. Although mycobacterial culture is the gold standard to identify TB and determine drug resistance, it takes 2 to 8 weeks to develop. Despite their high cost, nucleic acid amplification tests (NAATs) and whole-genome sequencing (WGS) are the commonly employed molecular-based methods for diagnosing and identifying TB. The WHO suggested the GeneXpert MTB/RIF to identify TB and detect resistance to rifampicin. In comparison, numerous molecular techniques were developed, including allele-specific PCR (MAS-PCR), solid-phase hybridization, real-time PCR (RT-PCR) and droplet digital PCR-based technique (DDPCR). This manuscript is intended to overview the current approaches for the phenotypic and genotypic diagnosis of TB disease and identifying resistance to antitubercular drugs depending on recently published articles, WHO and CDC reports, and commercially available diagnostic tools. [ABSTRACT FROM AUTHOR]

Background: Tuberculosis is a leading cause of mortality and morbidity in many countries across the world, including Pakistan. While systemic tuberculosis can involve any organ of the body, tubercular liver abscess is a rare presentation. Case Report: We report the case of an 8-year-old female from a developing country where tuberculosis poses a significant burden on the health care system. The patient presented with fever and weight loss for 6 months and abdominal pain for 14 days. On examination, she had tenderness and guarding over the right hypochondrium. Investigations revealed neutrophilic predominance in the complete blood count and elevated C-reactive protein. Imaging of the abdomen revealed ruptured liver abscess, extensive abdominal lymphadenopathy, and thrombus in the inferior vena cava. Gastric secretions were positive for Mycobacterium tuberculosis. Treatment included antitubercular and antithrombotic therapy. The patient was closely followed until she had completed the 1-year course of antitubercular therapy and was symptom-free. Conclusion: In tuberculosis-endemic countries, physicians should keep a high index of suspicion for tuberculosis in children who present with liver abscess and multisystem involvement. [ABSTRACT FROM AUTHOR]

In this study, new benzothiazole–pyrimidine hybrids (5a–c, 6, 7a–f, and 8–15) were designed and synthesised. Two different functionalities on the pyrimidine moiety of lead compound 4 were subjected to a variety of chemical changes with the goal of creating various functionalities and cyclisation to further elucidate the target structures. The potency of the new molecules was tested against different tuberculosis (TB) strains. The results indicated that compounds 5c, 5b, 12, and 15 (MIC = 0.24–0.98 µg/mL) are highly active against the first-line drug-sensitive strain of Mycobacterium tuberculosis (ATCC 25177). Thereafter, the anti-tubercular activity was evaluated against the two drug-resistant TB strains; ATCC 35822 and RCMB 2674, where, many compounds exhibited good activity with MIC = 0.98–62.5 3 µg/mL and 3.9–62.5 µg/mL, respectively. Compounds 5c and 15 having the highest anti-tubercular efficiency towards sensitive strain, displayed the best activity for the resistant strains by showing the MIC = 0.98 and 1.95 µg/mL for MDR TB, and showing the MIC = 3.9 and 7.81 µg/mL for XDR TB, consecutively. Finally, molecular docking studies were performed for the two most active compounds 5c and 15 to explore their enzymatic inhibitory activities. [ABSTRACT FROM AUTHOR]

The prevalence of Mycobacterium avium complex-pulmonary disease (MAC-PD) has become a growing concern worldwide, and current treatments involving macrolides (clarithromycin [CLR] or azithromycin), ethambutol, and rifampicin have limited success, highlighting the need for better therapeutic strategies. Recently, oxazolidinone drugs have been identified as novel anti-tuberculosis drugs effective against drug-resistant M. tuberculosis. However, the effects of these drugs against MAC are still controversial due to limited data. Here, we first evaluated the intracellular anti-MAC activities of two oxazolidinone drugs, linezolid (LZD) and delpazolid (DZD), against 10 macrolide-susceptible MAC strains and one macrolide-resistant M. avium strain in murine bone marrow-derived macrophages (BMDMs) and found that both drugs demonstrated similar potential. The synergistic efficacies with CLR were then determined in a chronic progressive MAC-PD murine model by initiating a 4-week treatment at 8 weeks post-infection. Upon assessment of bacterial burdens and inflamed lesions, oxazolidinone drugs exhibited no anti-MAC effect, and there was no significant difference in the synergistic effect of CLR between LZD and DZD. These findings suggest that oxazolidinone drugs inhibit intracellular bacterial growth, even against macrolide-resistant MAC, but their clinical application requires further consideration. [ABSTRACT FROM AUTHOR]

Background: The MeltPro TB assay (MeltPro) is a molecular rapid diagnostic test designed for detecting resistance to antituberculosis drugs. However, the performance of MeltPro as an initial diagnostic test for simultaneously detecting the presence of Mycobacterium tuberculosis (MTB) and drug resistance has not been evaluated. This study aims to assess the performance of MeltPro as initial diagnostic test for simultaneous detection of MTB and drug resistance in clinical samples from patients with presumptive pulmonary tuberculosis (PTB). Methods: A retrospective analysis was conducted on 1283 patients with presumptive PTB from two clinical centers, out of which 875 were diagnosed with PTB. The diagnostic accuracy of MeltPro, Xpert MTB/RIF (Xpert), and MGIT 960 for PTB detection was evaluated. Rifampicin (RIF), isoniazid (INH), ethambutol (EMB), streptomycin (STR), and fluoroquinolone (FQ) resistance were detected using MeltPro, with Xpert and/or the broth microdilution plate method (MYCOTB) results as references. Results: For the diagnosis of PTB, MeltPro showed a sensitivity of 69.0%, which was similar to Xpert (72.7%; P > 0.05) and higher than MGIT (58.1%; P < 0.001). The specificity of MeltPro was 97.1%, similar to Xpert (98.0%; P > 0.05). In smear-negative patients, MeltPro's sensitivity was 50.9%, similar to Xpert (56.5%; P > 0.05), and higher than MGIT (33.1%; P < 0.001). Based on Xpert and/or MYCOTB results, MeltPro exhibited a sensitivity and specificity of 98.3% and 99.2%, respectively, for detecting RIF resistance. Based on MYCOTB results, MeltPro's sensitivity for detecting resistance to INH, EMB, STR, and FQ was 96.4%, 89.1%, 97.5%, and 90.3%, respectively, with specificities of 96.0%, 96.0%, 95.2%, and 99.4%, respectively. Conclusion: The MeltPro TB assay could potentially be an effective alternative as the initial test for rapid diagnosis of PTB with drug-resistance detection in clinical practice. [ABSTRACT FROM AUTHOR]

A series of 5-(2-chloroquinolin-3-yl)-1,3,4-oxadiazole-2-amine (IIIa–IIIj) with different biological activities were designed and synthesized through the cyclization of semicarbazone. All the newly synthesized compounds were characterized by elemental analysis, 1H NMR, 13C NMR, FT-IR, and mass spectrometry. All the newly synthesized final compounds (IIIa–IIIj) were screened for in vitro antimicrobial activity by diffusion into agar wells using Gentamicin as the antibacterial agent and Fluconazole as the antifungal control. In addition, selected compounds were screened for antitubercular activity using Microplate Alamar Blue Assay (MABA). All the compounds were evaluated computationally for drug similarity using various pharmacokinetic studies and ADME-T characterization, then tested in vitro against Gram+ bacteria (Staphylococcus aureus and Bacillus subtilis), Gram– bacteria (S. typhi and P. aeruginosa), fungi (Aspergillus niger and Fusarium), as well as the Mycobacterium tuberculosis H37Rv strain, provided important information about activity against these strains. In the current study, we have discussed the method for the synthesis of 1,3,4-oxadiazole derivatives and summarized the role of compounds (IIIa), (IIIb), (IIId), (IIIg), (IIIh), and (IIIi) as potential antibacterial and antitubercular agents. We put forward further in vivo evaluation and biological activity evaluation for their use against these pathogens. [ABSTRACT FROM AUTHOR]

In the accompanying study, Nimmo and colleagues estimated the dates of emergence of mutations in mmpR5 (Rv0678), the most important resistance gene to the anti-tuberculosis drug bedaquiline, in over 3500 geographically diverse Mycobacterium tuberculosis genomes. This provided important insights to improve the design and analysis of clinical trials, as well as the World Health Organization catalogue of resistance mutations, the global reference for interpreting genotypic antimicrobial susceptibility testing results. [ABSTRACT FROM AUTHOR]

The article describes the case of a one-year-old Latino boy who had ten days of cough and nasal congestion followed by two days of fevers, decreased food intake, and diarrhea. Topics discussed include the most common pathogens associated with pediatric necrotizing pneumonia (NP) in the U.S., reason that diagnosis of tuberculosis (TB) in young children can be difficult, and standard treatment for TB.

Introduction Tuberculosis is a disease of diversified presentation. It affects almost all organs in the body, and otorhinolaryngological, head and neck involvement is not an exception. Objective To increase awareness about the different clinical presentations of otorhinolaryngological, head and neck tuberculosis, the techniques employed to diagnose it, and to assess the response to the treatment. Methods We conducted a prospective study of 114 patients who presented primarily with otorhinolaryngological, head and neck tuberculosis. Routine blood investigations, chest radiographs, the tuberculin test, and sputum examination for the presence of acid-fast bacilli were performed in all cases. Site-specific investigations were performed in relevant cases only. The patients were treated according to the antitubercular treatment (ATT) regimen recommended by the Indian Ministry of Health and Family Welfare's National Tuberculosis Elimination Program (NTEP), and they were followed up clinically two and six months after starting the ATT. Results Tubercular cervical lymphadenopathy was the most common clinical presentation (85.96%), followed by deep neck abscess (5.27%). Fine-needle aspiration cytology proved to be a reliable tool for the diagnosis of tubercular lymphadenopathy. Improvement at the end of 2 and 6 months of the ATT was observed in 90.35% and 96.50% of the cases respectively. Conclusion The diagnosis of otorhinolaryngological, head and neck tuberculosis requires a high index of clinical suspicion, and the ATT proved to be very effective in reducing the severity of the disease. [ABSTRACT FROM AUTHOR]

Introduction: Tuberculosis (TB) is a contagious disease and is one of the leading causes of death worldwide. TB is primarily caused by Mycobacterium Tuberculosis (MTB) and the percentage of Multi-Drug Resistance TB (MDR-TB) and Extensively Drug Resistance TB (XDR-TB) is increasing daily in many developing countries. Aim: To summarise different High-performance Liquid Chromatography (HPLC)-based methods for checking treatment adherence and drug monitoring of patients by estimating the amount of Anti-tubercular (Anti-TB) drugs in urine samples. Materials and Methods: The authors conducted a search and screened various databases (PubMed, Scopus, Web of Science, Google Scholar) using different keywords between April 2023 and June 2023. The authors included original research articles, clinical trials, and observational studies that focused on estimating anti-TB drugs in urine samples using HPLC. The authors excluded articles that employed methods other than HPLC for drug estimation in urine samples. A total of 13 articles were included in this review. Results: The authors identified 296 articles from different electronic databases and four articles from other sources (Google Scholar, ResearchGate, etc.). Ultimately, 13 articles were included describing HPLC-based methods for determining anti-TB drugs in urine samples. Data was extracted focusing on mobile phases and sample preparation/extraction procedures. Two articles of 2004 and 2014 reported simple mobile phases and sample preparation methods for estimating rifampicin and isoniazid. Additionally, articles published in the last five years have employed simple mobile phases with minimal or no extraction procedures. Conclusion: The present review summarises various HPLCbased methods reported in the literature, as it is considered the gold standard method for checking treatment adherence in TB patients. Urine samples were chosen for ease of collection, particularly from patients of different age groups, including the paediatric population. This review highlights the need for more HPLC-based methods with simple mobile phases and extraction procedures for early detection of anti-TB drugs in resource-poor settings. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Cortical venous thrombosis is a rare but severe complication of TBM that requires a high index of suspicion for early diagnosis. The treatment of CVT in TBM is based on anticoagulant therapy, which is known to improve the outcomes of the patients. The case report describes an 18‐year‐old male in India with symptoms of tubercular meningitis complicated by cortical venous thrombosis. Tubercular meningitis is a rare but severe form of meningitis caused by tuberculosis bacteria and is a significant public health concern in India. The patient presented to the emergency department with a history of fever, headache, and vomiting for the past month, with a positive Mycobacterium tuberculosis test. The patient was started on standard antitubercular therapy and was diagnosed with cortical venous thrombosis via an MRI scan. Treatment included antitubercular therapy, anticoagulation therapy, dexamethasone, and antiemetic drugs. The patient's symptoms improved over 2 weeks of therapy. The case highlights the importance of early detection, treatment, and prevention strategies, such as the National Tuberculosis elimination program, in controlling the spread of tuberculosis in India. It also emphasizes the importance of close monitoring for complications in patients with tubercular meningitis, such as cortical venous thrombosis, which can be life‐threatening. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) is a chronic granulomatous infection which primarily affects lungs. It is caused by Mycobacterium tuberculosis which was discovered by Dr Robert Koch. It can also affect other organs. Tuberculosis is a major cause of morbidity and mortality in developing countries. Early detection and initiation of antitubercular therapy are important in the management of TB. Extrapulmonary TB might not exhibit same features as pulmonary tuberculosis. Tuberculosis of maxilla is an extremely rare entity which can be misdiagnosed as carcinoma of maxillary sinus or other infectious conditions. We are presenting a case of tuberculous osteomyelitis of maxilla in a 14-year-old female who came with a discharging sinus over the right cheek. She underwent endoscopic debridement of sinuses and histopathological examination was suggestive of Koch's infection. Patient was further treated with antitubercular therapy and showed significant improvement at four weeks follow up. [ABSTRACT FROM AUTHOR]

We designed, synthesized, and tested twenty-six novel tetrahydroisoquinoline carbohydrazide compounds for their anti-mycobacterial activity. Utilizing mass spectrometry, 1H NMR, 13C NMR, and elemental analysis, all the synthesized derivative structures were confirmed. The final analogs were tested for their ability to inhibit Mycobacterium tuberculosis (Mtb). The Mtb inhibitory activity outcomes varied from 0.78 to 25 μg mL−1. Among all the investigated analogues, compounds NFT-12, NFT-19, and NFT-20 exhibited substantial activity with a MIC of 0.78 μg mL−1 against Mtb H37Rv. Furthermore, the NFT-11 compound showed excellent activity with a MIC of 1.56 μg mL−1. The majority of the compounds showed very good activity compared to the standard drug rifampicin (MIC 3.12 μg mL−1). The most active compounds, NFT-12, NFT-19, and NFT-20, demonstrated selectivity over the normal human embryonic kidney cell line (HEK293T) with a selectivity index of >40. To determine whether the designed compounds exhibit synergistic effects or not, drug–inhibitor combination studies were carried out for the most active compounds using the standard drugs isoniazid, rifampicin, ciprofloxacin, and streptomycin. The improvement in pharmacological activities (x/y coefficients) demonstrates the effectiveness of the compounds NFT-12, NFT-19, and NFT-20 with isoniazid. The expected binding site of the test ligand at the active site of the chosen target proteins was determined using molecular docking studies. The most active compounds NFT-12, NFT-19, and NFT-20 were used in the docking experiments to determine the binding pattern at the active site with the Mycobacterium tuberculosis InhA (PDB ID: 4OHU , 1.60 Å). [ABSTRACT FROM AUTHOR]

New antitubercular agents with either a novel mode of action or novel mode of inhibition are urgently needed to overcome the threat of drug-resistant tuberculosis (TB). The present study profiles new arylated quinoline carboxylic acids (QCAs) having activity against replicating and non-replicating Mycobacterium tuberculosis (Mtb), the causative agent of TB. Thus, the synthesis, characterization, and in vitro screening (MABA and LORA) of 48 QCAs modified with alkyl, aryl, alkoxy, halogens, and nitro groups in the quinoline ring led to the discovery of two QCA derivatives, 7i and 7m, adorned with C-2 2-(naphthalen-2-yl)/C-6 1-butyl and C-2 22-(phenanthren-3-yl)/C-6 isopropyl, respectively, as the best Mtb inhibitors. DNA gyrase inhibition was shown to be exhibited by both, with QCA 7m illustrating better activity up to a 1 μM test concentration. Finally, a docking model for both compounds with Mtb DNA gyrase was developed, and it showed a good correlation with in vitro results. [ABSTRACT FROM AUTHOR]

A new series of symmetric acridin-9-yl-bis-benzothiazol-2-yl-amines have been synthesized in good to excellent yields by intra-molecular cyclization of 1-acridin-9-yl-1-benzothiazol-2-yl-3-aryl thiourea and screened for their in vitro antitubercular activity against Mycobacterium tuberculosis by BACTEC radiometric method. The synthesis of new analogues bearing an acridine-linked chloro-substituted benzothiazole has demonstrated enhanced antituberculosis activity. [ABSTRACT FROM AUTHOR]

Mycobacterium tuberculosis (Mtb) is the etiological agent of tuberculosis (TB), a disease that, although preventable and curable, remains a global epidemic due to the emergence of resistance and a latent form responsible for a long period of treatment. Drug discovery in TB is a challenging task due to the heterogeneity of the disease, the emergence of resistance, and uncomplete knowledge of the pathophysiology of the disease. The limited permeability of the cell wall and the presence of multiple efflux pumps remain a major barrier to achieve effective intracellular drug accumulation. While the complete genome sequence of Mtb has been determined and several potential protein targets have been validated, the lack of adequate models for in vitro and in vivo studies is a limiting factor in TB drug discovery programs. In current therapeutic regimens, less than 0.5% of bacterial proteins are targeted during the biosynthesis of the cell wall and the energetic metabolism of two of the most important processes exploited for TB chemotherapeutics. This review provides an overview on the current challenges in TB drug discovery and emerging Mtb druggable proteins, and explains how chemical probes for protein profiling enabled the identification of new targets and biomarkers, paving the way to disruptive therapeutic regimens and diagnostic tools. [ABSTRACT FROM AUTHOR]

Novel antitubercular compounds are urgently needed to combat drug-resistant Mycobacterium tuberculosis (Mtb). Filamentous actinobacteria have historically been an excellent source of antitubercular drugs. Despite this, drug discovery from these microorganisms has fallen out of favour due to the continual rediscovery of known compounds. To increase the chance of discovering novel antibiotics, biodiverse and rare strains should be prioritised. Subsequently, active samples need to be dereplicated as early as possible to focus efforts on truly novel compounds. In this study, 42 South African filamentous actinobacteria were screened for antimycobacterial activity using the agar overlay method against the Mtb indicator Mycolicibacterium aurum under six different nutrient growth conditions. Known compounds were subsequently identified through extraction and high-resolution mass spectrometric analysis of the zones of growth inhibition produced by active strains. This allowed the dereplication of 15 hits from six strains that were found to be producing puromycin, actinomycin D and valinomycin. The remaining active strains were grown in liquid cultures, extracted and submitted for screening against Mtb in vitro. Actinomadura napierensis B60T was the most active sample and was selected for bioassay-guided purification. This resulted in the identification of tetromadurin, a known compound, but which we show for the first time to have potent antitubercular activity, with the MIC90s within the range of 73.7–151.6 nM against M. tuberculosis H37RvT in vitro under different test conditions. This shows that South African actinobacteria are a good source of novel antitubercular compounds and warrant further screening. It is also revealed that active hits can be dereplicated by HPLC-MS/MS analysis of the zones of growth inhibition produced by the agar overlay technique. [ABSTRACT FROM AUTHOR]

Background and Objectives: In clinical diagnostics, molecular methods are used to detect Mycobacterium tuberculosis bacilli (MTB) and to distinguish them from non-tuberculous mycobacteria (NTM). They are also used to make the right treatment decision for the patient as soon as possible. The aim of this study was to establish a rapid and novel multiplex PCR (mPCR) assay for the detection and differentiation of MTB and NTM in a single tube. Materials and Methods: 100 sputum samples positive for acid-fast bacilli (AFB) were included in this study. Mycobacterial culture, biochemical tests, and antibiotic susceptibility testing were performed on samples. After alkaline decontamination, total DNA was extracted from the samples. A primer pair targeting the rpoB gene, encoding the beta-subunit of RNA polymerase, was used to detect MTB and NTM, amplifying a 235-bp fragment of MTB and a 136-bp sequence of NTM. A pair of primers targeting a 190-bp fragment of the IS6110 region of MTB was also used to confirm the results. The sensitivity and specificity of the mPCR assay were evaluated using DNA extracted from standard strains. The amplified products were then analyzed by conventional agarose gel electrophoresis. Results: Of 100 AFB smear-positive sputum samples, 92 MTB DNA, 7 NTM DNA, and one mixed-infection sample were identified in a single tube using mPCR assay. There was no correlation between the AFB degree of smear positivity and PCR results. Of seven NTM isolates, 6 (86%) were resistant to rifampin, isoniazid, and ethambutol, the three first-line anti-tuberculosis drugs. Conclusion: A single-tube mPCR assay based on the rpoB gene provides a rapid and reliable means of detecting and differentiating MTB and NTM in sputum specimens. [ABSTRACT FROM AUTHOR]

A chemoselective chlorination of nitroolefin was accomplished, and the resulting monochlorinated nitroolefin underwent [3+2]-cycloadditions with in-situ generated azomethine-ylide to afford spiro pyrrolidine-oxindoles. All the compounds were tested against exponentially growing Mycobacterium tuberculosis H37Ra (Mtb-Ra) cells. Two of the compounds exhibited 90% inhibition at 3.125 µM and 6.25 µM concentrations, respectively. The ex vivo activity assay in macrophage J774A.1 cell line showed one log Colony Forming Unit (CFU) reduction for both compounds after 24 h and approximately 2 log reduction after 48 h, suggesting almost 99% killing of Mtb-Ra after 48 h of exposure in macrophages. Although the cytotoxicity studies with both compounds showed low toxicity at MIC values for both compounds, given the efficient killing of Mtb-Ra in macrophages, the present group of compounds is interesting, and further work is in progress to reduce the toxicity of these compounds for further activity studies. SYNOPSIS. Chemoselective chlorination of nitroolefins using iodobenzene dichloride (IBDC) was carried out to obtain monochlorinated nitroolefins. This was further demonstrated for [3+2]-cycloadditions with azomethine ylide and isatin to synthesize spiropyrrolidine oxindoles. This work also presents that two of the synthesized compounds was able to exhibit good activity against Mycobacterium tuberculosis H37Ra (Mtb-Ra) cells. [ABSTRACT FROM AUTHOR]

In this study, we assessed the potential of bacteriocins and their in vitro synergistic effects in combination with anti-tuberculosis drugs against Mycobacterium tuberculosis. We evaluated the in vitro activity of chemically synthesized bacteriocins in combination with rifampicin (RIF), ofloxacin, and moxifloxacin against the reference M. tuberculosis H37Rv and a clinical-resistant strain. We first screened the bacteriocin PARAGEN collection and found active bacteriocins. We then determined their minimal inhibitory concentration (MIC), minimal bactericidal concentration, and their fractional inhibitory index by the checkerboard microdilution assay. Remarkably, we identified four bacteriocins with interesting antimycobacterial activity alone and in combinations with RIF, ofloxacin, and moxifloxacin, with significant reduction of the MIC that showed impressive synergistic effects against the susceptible and resistant clinical strains. In conclusion, our preliminary results show promising bacteriocins candidate used in a synergistic combination with anti-tuberculosis drugs and emphasize the need for combined therapy as a new strategy to enhance the activity of existing drugs, which may confer very promising therapeutic benefits against M. tuberculosis. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) caused by Mycobacterium tuberculosis manifests as pulmonary and extrapulmonary forms with cutaneous TB being rare and TB of scalp even rarer. We report the case of a 13-year-old girl who was admitted with a 4-week history of painful swelling and ulcer on the scalp and occasional cough. She had a history of falling on the head 6 months ago. On physical examination, the ulcer measured 6 cm in diameter and was tender with a yellowish-white crust. Contrast-enhanced computed tomography of the head showed a well-defined hypodense peripherally enhancing lesion overlying the left parietal bone with the destruction of the underlying bone. A clinical diagnosis of frontal bone osteomyelitis was made. Abscess drainage was done with excision of the lesion which on histopathological examination showed abundant necrosis with few ill defined epithelioid cell granulomas, langhans type of giant cells, and chronic inflammatory infiltrates. Ziehl–Neelsen staining for acid-fast bacilli was negative, whereas molecular testing by GeneXpert Rifampicin Assay was positive for M. tuberculosis. Thus, a diagnosis of tubercular osteomyelitis was made. Our patient was prescribed four drugs antitubercular regimen for 1 year. On follow-up after 6 months, she is doing fine without any signs and symptoms of the disease. TB should always be kept in mind as the differential diagnosis keeping its varied presentation and high prevalence in our country. [ABSTRACT FROM AUTHOR]

Tuberculosis is an extremely serious problem of global public health. Its incidence is worsened by the presence of multidrug-resistant (MDR) strains of Mycobacterium tuberculosis. More serious forms of drug resistance have been observed in recent years. Therefore, the discovery and/or synthesis of new potent and less toxic anti-tubercular compounds is very critical, especially having in mind the consequences and the delays in treatment caused by the COVID-19 pandemic. Enoyl-acyl carrier protein reductase (InhA) is an important enzyme involved in the biosynthesis of mycolic acid, a major component of the M. tuberculosis cell wall. At the same time, it is a key enzyme in the development of drug resistance, making it an important target for the discovery of new antimycobacterial agents. Many different chemical scaffolds, including hydrazide hydrazones and thiadiazoles, have been evaluated for their InhA inhibitory activity. The aim of this review is to evaluate recently described hydrazide-hydrazone- and thiadiazole-containing derivatives that inhibit InhA activity, resulting in antimycobacterial effects. In addition, a brief review of the mechanisms of action of currently available anti-tuberculosis drugs is provided, including recently approved agents and molecules in clinical trials. [ABSTRACT FROM AUTHOR]

A desirable and established target for creating antituberculosis drug lead molecules is the Mycobacterium tuberculosis enoyl-acyl carrier protein reductase InhA. Additionally, direct inhibitors of InhA continue to be effective against InhA variants with mutations linked to isoniazid resistance, providing the possibility of activity against MDR isolates. Initially, we isolated monoterpenoid 1,8-cineole from leaf parts of the Callistemon citrinus by aqueous ethanol extract, followed functionalization with several functional groups, and we created a novel 1,8-cineole analogue as a novel compound for treating tuberculosis infection. This study used a structure-based virtual screening of 20 structures to identify novel lead InhA inhibitors as potential antituberculosis drugs. Compound (SG01) was identified as a lead candidate for the synthesis and has been characterized by IR, 1H, 13C NMR, and mass spectroscopy. Using a microplate Alamar Blue assay method, the compound was also tested for their in vitro antimycobacterial activity against the H37Rv strain. This compound offers a desirable starting point for ligand optimization attempts to find new and potent anti-tuberculosis drugs that target InhA. [ABSTRACT FROM AUTHOR]