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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]

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]

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]

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]

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]

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]

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]

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]

Pyrazinamide plays an important role in the treatment of tuberculosis. However, the microbiological test for pyrazinamide resistance is more complex and less reliable than testing of susceptibility to other anti-tuberculosis drugs due to the need to grow the pathogen at pH 5.5. Identification of mutations that cause resistance to anti-tuberculosis drugs can replace microbiological methods. Mutations in the pncA gene are responsible for the main mechanism of the resistance to pyrazinamide and are found in more than 90% of resistant strains. However, the genetic method for determining drug susceptibility is very complex, because mutations leading to pyrazinamide resistance are diverse and scattered throughout the gene. We have developed a software package for automatic data interpretation and prediction of the resistance to pyrazinamide based on Sanger sequencing results. The effectiveness of detection of pyrazinamide resistance in 16 clinical samples was compared using the BACTEC MGIT 960 automated system and pncA gene Sanger sequencing with automated analysis of the results. A significant advantage of the developed method over a single microbiological study was shown, due to greater reliability of the results irrespective of the purity of isolates. [ABSTRACT FROM AUTHOR]

An in-depth understanding of the lung microbiota in tuberculosis (TB) infection could provide optimal strategies for the prophylaxis, diagnosis, and treatment of the disease. Only a few studies have investigated the impact of Mycobacterium tuberculosis (Mtb) infection and anti-TB treatment on the lung microbiota. Bronchoalveolar lavage fluid and blood samples were collected from 23 active TB patients (TBZ), 17 latent tuberculosis infection patients (LTBI), 13 healthy controls (HC), and 14 active TB patients with 1-month anti-TB therapy (TBM) for 16S RNA sequencing and serological indexes, respectively. Low body mass index, albumin, and total triglyceride levels were detected in TBZ. Pulmonary Mtb infection led to a minor decrease in the alpha diversity of the lung microbiota in TBZ than HC, but a significant difference was noted in beta diversity. Subsequently, anti-TB therapy caused a rapid alteration in the lung community structure due to reduced alpha and beta diversity. Proteobacteria were abundant in TBZ samples, while Firmicutes was predominant in the LITB and HC samples. Lactobacillus and Subdoligranulum (genera) were the most unique in the LTBI and HC group, respectively. The TBM group showed the most predominant abundance of Bacteroides, Oscillospira, and Ruminococcus (genera). Functional pathways, such as indole alkaloid biosynthesis, Wnt signaling pathway, endocytosis, and metabolism of xenobiotics by cytochrome P450, significantly decreased in the TBM group compared with TBZ group. Pulmonary TB and anti-TB treatment caused a distinct dysbiosis of the lung microbiome. The current findings suggested potential links between the lung microbiota and TB onset, progression, and treatment. [ABSTRACT FROM AUTHOR]

A series of bis-triazole conjugates, N-aryl-2-(4-{[(1H-1,2,3-benzotriazol-1-yl)oxy]methyl}-1H-1,2,3-triazol-1-yl)acetamides, have been synthesized via copper-catalyzed azide–alkyne cycloaddition, and their antitubercular activity against the human virulent H37Rv strain of Mycobacterium tuberculosis and anti-microbial activity against some gram-positive and gram-negative bacteria and fungal strains have been evaluated. The synthesized derivatives with a 2,4-difluorophenyl and 4-nitrophenyl group on the amide nitrogen atom were the most active against M. tuberculosis with excellent MIC, IC50, and IC90 values (12, 15, 16 µM and 48, 53, 62 µM, respectively). The highest antimicrobial activity was found for halogen-substituted compounds (MIC 0.24–16 µg/mL), while derivatives with electron-donating groups showed the lowest activity. [ABSTRACT FROM AUTHOR]

There is an urgent need to validate new drug targets and identify small molecules that possess activity against both drug-resistant and drug-sensitive bacteria. The enzymes belonging to amino acid biosynthesis have been shown to be essential for growth in vitro, in vivo and have not been exploited much for the development of anti-tubercular agents. Here, we have identified small molecule inhibitors targeting homoserine acetyl transferase (HSAT, MetX, Rv3341) from M. tuberculosis. MetX catalyses the first committed step in L-methionine and S-adenosyl methionine biosynthesis resulting in the formation of O-acetyl-homoserine. Using CRISPRi approach, we demonstrate that conditional repression of metX resulted in inhibition of M. tuberculosis growth in vitro. We have determined steady state kinetic parameters for the acetylation of L-homoserine by Rv3341. We show that the recombinant enzyme followed Michaelis–Menten kinetics and utilizes both acetyl-CoA and propionyl-CoA as acyl-donors. High-throughput screening of a 2443 compound library resulted in identification of small molecule inhibitors against MetX enzyme from M. tuberculosis. The identified lead compounds inhibited Rv3341 enzymatic activity in a dose dependent manner and were also active against HSAT homolog from S. aureus. Molecular docking of the identified primary hits predicted residues that are essential for their binding in HSAT homologs from M. tuberculosis and S. aureus. ThermoFluor assay demonstrated direct binding of the identified primary hits with HSAT proteins. Few of the identified small molecules were able to inhibit growth of M. tuberculosis and S. aureus in liquid cultures. Taken together, our findings validated HSAT as an attractive target for development of new broad-spectrum anti-bacterial agents that should be effective against drug-resistant bacteria. [ABSTRACT FROM AUTHOR]

The emergence of drug-resistant strains of the Mycobacterium tuberculosis (MTB) has challenged tuberculosis control programs. So far, few studies using the 24-locus mycobacterial interspersed repetitive unit variable number tandem repeats (MIRU-VNTR) have investigated the genetic diversity of MTB in Iran. This study aimed to determine the genetic diversity of MTB isolates resistant to first-line anti-tuberculosis drugs using 24-locus MIRU-VNTR in southwestern Iran. Out of 6620 MTB clinical isolates, 29 resistant isolates to one or more isoniazid, rifampin, and ethambutol were detected using drug susceptibility testing by the proportional method. The manual 24-locus MIRU-VNTR was used to determine the MTB resistant isolates' phylogenetic relationship. MIRU-VNTRplus web application tools were applied to analyze the associated data. Using 24-locus MIRU-VNTR, 13.8% of isolates (n = 4) were distributed in two clusters, and the remaining 86.2% (n = 25) showed a unique pattern. Four clonal complexes were observed in the minimum spanning tree based on the double-locus variant. Most isolates belonged to Delhi/CAS (34.5%, 10/29) and NEW-1 (24.1%, 7/29) sub-lineages, followed by EAI and LAM with a frequency of 6.9% (2/29) and 3.5% (1/29), respectively. Eight isolates (27.6%) did not match any genotype in the database. The 24-locus MIRU-VNTR showed a high discriminatory power; however, the 15-locus and 12-locus set analyses were more discriminative. Our study revealed a high degree of genetic diversity among drug-resistant MTB isolates, which could be interpreted as the low rate of person-to-person transmission in this region. The 15-locus MIRU-VNTR would be recommended for preliminary genotyping of drug-resistant MTB. [ABSTRACT FROM AUTHOR]

Mycobacterium tuberculosis (M. tb), the etiological agent of tuberculosis (TB), poses a severe challenge for public health and remains the number one cause of death as a single infectious agent. There are 10 million active cases of TB per year with 1.5 million deaths, and 2–3 billion people are estimated to harbor latent M. tb infection. Moreover, the emergence of multi-drug-resistant (MDR), extremely-drug-resistant (XDR), and the recent totally drug-resistant (TDR) M. tb is becoming a global issue that has fueled the need to find new drugs different from existing regimens. In these circumstances, probiotics can be a potential choice, so we focused on developing them as an anti-tuberculosis drug candidate. Here, we report the anti-tubercular activities of Lacticaseibacillus rhamnosus PMC203 isolated from the vaginal microbiota of healthy women. PMC203 exhibited a promising intracellular killing effect against both drug-sensitive and resistant M. tb infected murine macrophage cell line RAW 264.7 without showing any cytotoxicity. Additionally, it also inhibited the growth of M. tb under broth culture medium. PMC203 did not cause weight change or specific clinical symptoms in a 2-week repeated oral administration toxicity test in a guinea pig model. Here, we also found that PMC203 induces autophagy in a dose dependent manner by increasing the signal of well-known autophagy gene markers, suggesting a possible intracellular killing mechanism. [ABSTRACT FROM AUTHOR]

Chitosan (CS) is a promising biopolymer and has been tested as a complement to the action and compensation of toxicity presented by anti-tuberculosis drugs. The present work studied the adjuvant effect of CS with the drug ethambutol (EMB) as a compound (CS-EMB), to explore its antimicrobial and cytotoxic activity, using transmission electron microscopy (TEM), to examine ultracellular changes that represent possible antimycobacterial action of CS on Mycobacterium tuberculosis (Mtb). Antimycobacterial activities were tested against reference strains Mtb ATCC® H37Rv and multidrug resistant (MDR). In vitro cytotoxicity tests were performed on Raw 264.7. For the studied compounds, morphological, ultrastructural, and physical–chemical analyses were performed. Drug-polymer interactions that occur through the H bridges were confirmed by physical–chemical analyses. The CS-EMB compound is stable at pHs of 6.5–7.5, allowing its release at physiological pH. The antibacterial activity (minimum inhibitory concentration) of the CS-EMB compound was 50% greater than that of the EMB in the H37Rv and MDR strains and the ultrastructural changes in the bacilli observed by TEM proved that the CS-EMB compound has a bactericidal action, allowing it to break down the Mtb cell wall. The cytotoxicity of CS-EMB was higher than that of isolated EMB, IC50 279, and 176 μg/mL, respectively. It is concluded that CS-EMB forms a promising composite against strains Mtb H37Rv and multidrug resistant (MDR-TB). Key points • Our study will be the first to observe ultrastructurally the effects of the CS-EMB compound on Mtb cells. • CS-EMB antimicrobial activity in a multidrug-resistant clinical strain. • The CS-EMB compound has promising potential for the development of a new drug to fight tuberculosis. [ABSTRACT FROM AUTHOR]

Ergothioneine (EGT) is a low molecular weight histidine betaine essential in all domains of life but only synthesized by selected few organisms. Synthesis of EGT by Mycobacterium tuberculosis (M. tb) is critical for maintaining bioenergetic homeostasis and protecting the bacterium from alkylating agents, oxidative stress, and anti-tubercular drugs. EgtD, an S-adenosylmethionine-dependent methyltransferase (AdoMet), catalyzes the trimethylation of L-Histidine to initiate EGT biosynthesis and this reaction has been shown to be essential for EGT production in mycobacteria and for long-term infection of murine macrophages by M. tb. In this work, library screening and structure-guided strategies identified multiple classes of M. tb EgtD inhibitors that bind in various regions of the enzyme active site. X-ray crystal structures of EgtD-inhibitor complexes confirm that L-Histidine analogs bind solely to the L-Histidine binding site while drug-like inhibitors, such as TGX-221, and S-Glycyl-H-1152 span both the L-Histidine and AdoMet binding sites. These enzyme-inhibitor complexes provide detailed structural information of compound scaffolds useful for developing more potent inhibitors that could shorten Tuberculosis treatment regimens by weakening important bacterial defenses. [ABSTRACT FROM AUTHOR]

Background: Very few studies report resistance pattern exclusively in musculoskeletal tuberculosis (MSK-TB). Methods: This study of 100 pus samples from patients of MSK-TB with active disease in whom Mycobacterium tuberculosis (MTB) was detected by cartridge-based nucleic acid amplification test (CBNAAT), revealed the pattern of resistance among newly diagnosed and previously treated cases. Liquid culture and drug susceptibility testing (DST) using MGIT 960 was done for 11 anti-tubercular drugs. Results: Among these 100 cases; 22% were AFB positive; MGIT 960 detected MTB in 58.33% (35/60) new cases and 30.0% (12/40) previously treated cases. Five new and 10 previously treated cases had drug resistance and 12 were detected rifampicin resistance (Rif-R) by CBNAAT. Among new cases MGIT-DST detected mono-INH resistant in 2.86% (1/35), mono-STR resistant in 2.86% (1/35), MDR-TB in 5.7% (2/35) and pre-XDR in 2.9%(1/35).Among previously treated cases Rif-R was found in 10% (4/40) where MTB was not detected by MGIT and MGIT-DST detected mono-INH resistant in 8.33% (1/12); MDR-TB in 8.33% (1/12) and pre-XDR in 33.3%. There were no cases of XDR-TB. Conclusion: High disease burden of various type drug resistance were seen more commonly in previously treated cases and was not uncommon in new cases of MSK-TB. Both CBNAAT and DST are essential for detecting resistance pattern in MSK-TB. [ABSTRACT FROM AUTHOR]

Antibiotic resistance is a major problem of tuberculosis treatment. This provides the stimulus for the search of novel molecular targets and approaches to reduce or forestall resistance emergence in Mycobacterium tuberculosis. Earlier, we discovered a novel small-molecular inhibitor among 3-phenyl-5-(1-phenyl-1H-[1,2,3]triazol-4-yl)-[1,2,4]oxadiazoles targeting simultaneously two enzymes—mycobacterial leucyl-tRNA synthetase (LeuRS) and methionyl-tRNA synthetase (MetRS), which are promising molecular targets for antibiotic development. Unfortunately, the identified inhibitor does not reveal antibacterial activity toward M. tuberculosis. This study aims to develop novel aminoacyl-tRNA synthetase inhibitors among this chemical class with antibacterial activity toward resistant strains of M. tuberculosis. We performed molecular docking of the library of 3-phenyl-5-(1-phenyl-1H-[1,2,3]triazol-4-yl)-[1,2,4]oxadiazole derivatives and selected 41 compounds for investigation of their inhibitory activity toward MetRS and LeuRS in aminoacylation assay and antibacterial activity toward M. tuberculosis strains using microdilution assay. In vitro screening resulted in 10 compounds active against MetRS and 3 compounds active against LeuRS. Structure-related relationships (SAR) were established. The antibacterial screening revealed 4 compounds active toward M. tuberculosis mono-resistant strains in the range of concentrations 2–20 mg/L. Among these compounds, only one compound 27 has significant enzyme inhibitory activity toward mycobacterial MetRS (IC50 = 148.5 µM). The MIC for this compound toward M. tuberculosis H37Rv strain is 12.5 µM. This compound is not cytotoxic to human HEK293 and HepG2 cell lines. Therefore, 3-phenyl-5-(1-phenyl-1H-[1,2,3]triazol-4-yl)-[1,2,4]oxadiazole derivatives can be used for further chemical optimization and biological research to find non-toxic antituberculosis agents with a novel mechanism of action. [ABSTRACT FROM AUTHOR]

Mycobacterium tuberculosis cells contain two apurinic/apyrimidinic (AP) endonucleases, endonuclease IV (MtbEnd) and exonuclease III (MtbXthA), the former playing a dominant role in protecting mycobacterial DNA from oxidative stress. Mycobacterial endonuclease IV substantially differs from its homologs found in Escherichia coli and other proteobacteria in a number of conserved positions important for DNA binding and AP site recognition. The M. tuberculosis end gene was cloned, and recombinant MtbEnd purified and characterized. The protein efficiently hydrolyzed DNA at the natural AP site and its 1′-deoxy analog in the presence of divalent cations, of which Ca2+, Mn2+, and Co2+ supported the highest activity. Exonuclease activity was not detected in MtbEnt preparations. The pH optimum was estimated at 7.0–8.0; the ionic strength optimum, at ~50 mM NaCl. Enzymatic activity of MtbEnd was suppressed in the presence of methoxyamine, a chemotherapeutic agent that modifies AP sites. Based on the results, MtbEnd was assumed to provide a possible target for new anti-tuberculosis drugs. [ABSTRACT FROM AUTHOR]

Tuberculosis is the most dangerous disease causing maximum deaths than any other, caused by single infectious agent. Due to multidrug resistant of Mycobacterium tuberculosis strains, there is a need of new drugs and drug targets. In this work, we have selected RmlD (α-dTDP-6-deoxy-lyxo-4-hexulose reductase) in the dTDP Rhamnose pathway as drug target to control tuberculosis using Rhodanine analogues. In order to study interaction of RmlD with Rhodanine analogues, a three-dimensional model based on crystal structures such as 1VLO from Clostridium, 1KBZ from Salmonella typhimurium, and 2GGS from Sulfolobus was generated using Modeller 9v7. The modeled structure reliability has been checked using programs such as Procheck, What if, Prosa, Verify 3D, and Errat. In an attempt to find new inhibitors for RmlD enzyme, docking studies were done with a series of Rhodanine and its analogues. Detailed analysis of enzyme-inhibitor interactions identified specific key residues, SER5, VAL9, ILE51, HIS54, and GLY55 which were important in forming hydrogen bonds in binding affinity. Homology modeling and docking studies on RmlD model provided valuable insight information for designing better inhibitors as novel anti-tuberculosis drugs by rational method. [ABSTRACT FROM AUTHOR]

The emergence of multi-drug resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis creates the urgency for new anti-tuberculosis drugs to improve the efficiency of current tuberculosis treatment. In the search for a new potential tuberculosis drug, we synthesized an isoindole based chemical library and screened a potential candidate with significant anti-tuberculosis activity. The compound named 2-hydroxy-4-(4-nitro-1,3-dioxoisoindolin-2-yl) benzoic acid (IDD-B40) showed strong activity against all the tested drug-susceptible and drug-resistant strains of M. tuberculosis, with the 50% minimum inhibitory concentrations (MIC50) of 0.39 μg/ml both in culture broth and inside Raw 264.7 cells. Also, IDD-B40, in combination with rifampicin, exhibited a direct synergistic effect against both XDR and H37Rv M. tuberculosis. Besides, IDD-B40 showed a better post-antibiotic effect (PAE) than did some first-line drugs and showed no significant cytotoxicity to any cell line tested, with a selectivity index of ≥ 128. Although IDD-B40 showed a result similar to isoniazid in the preliminary mycolic acid inhibition assay, it did not exhibit any effect against other mycolic acid-producing nontuberculous mycobacterial strains (NTM), and different non-mycobacterial pathogenic strains, so further studies are required to confirm the mode of action of IDD-B40. Considering its results against M. tuberculosis, IDD-B40 is a potential anti-tuberculosis drug candidate. However, further studies are required to evaluate its potential in vivo effect and therapeutic potential. [ABSTRACT FROM AUTHOR]

A series of new thiazolidine-2,4-dione and hydantoin derivatives were synthesized by Knoevenagel condensation.. The compounds were identified by their melting points, 1H NMR, 13C NMR, and HR-MS spectral data. The in vitro antimycobacterial activity was evaluated against reference strain Mycobacterium tuberculosis H37Rv and compared to that of the first-line antituberculosis drugs isoniazid (INH) and ethambutol (EMB). The new compounds showed promising antimycobacterial activity (MIC ranging from 0.75 to 1.54 µM) and low cytotoxicity in the human embryonic kidney cell line HEK-293T (IC50 > 200 µM). The most potent compounds (IIIa) and (V) could be promising drug candidates for further development. In silico ADME screening revealed the biological potential of all synthesized compounds using SwissADME online biological activity prediction software. Molecular docking studies were carried out as well to confirm the groove mode of binding and receptor-complex interactions. [ABSTRACT FROM AUTHOR]

A novel series of analogues based on 5-(1-(4-chloro-3-methoxyphenyl)piperidin-4-yl)-4-phenyl-2H-1,2,4-triazole-3(4H)-thione core have been synthesized and their potential as antibacterial, antifungal and antitubercular agents was examined. The structure-activity relationship (SAR) studies of these derivatives 5 (a–k) clearly indicate the vital role of lipophilicity as a major factor in enhancing the biological activity of these compounds. Among the compounds screened, 5a, 5c, 5d, 5j and 5k displayed significant activity against Mycobacterium tuberculosis H37Rv strain. [ABSTRACT FROM AUTHOR]

The use of lytic mycobacteriophages to treat tuberculosis under conditions of acquired resistance to anti-tuberculosis drugs is one of the most practical ways to improve the effectiveness of therapy and reduce the spread of this disease. We studied the efficacy of antimycobacterial action of mycobacteriophage D29 encapsulated into 400-nm liposomes in cell models of tuberculosis infection in vitro. The antimycobacterial action of lytic mycobacteriophage D29 used in free or liposome-encapsulated forms was demonstrated on cell models of intracellularly infected RAW264.7 macrophages and tuberculous granuloma formed by human blood mononuclear cells. The experiments demonstrated pronounced advantage of liposomal form of mycobacteriophage according to the criteria of their penetration into macrophages and lysis of Mycobacterium tuberculosis in culture. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the sensitivity patterns of anti-tubercular drugs in Xpert MTB-positive spinal tuberculosis (TB) patients and to formulate the guidelines for early start of empiric anti-tubercular treatment (ATT) in MDR-TB spine based on resistance pattern in this large series.Methods: It was a cross-sectional observational study of 252 consecutive patients who were Xpert MTB-proven spinal TB cases with retrospective analysis of prospective data. The Xpert MTB/RIF (Mycobacterium tuberculosis/rifampicin) assay was used to diagnose spinal TB and RIF resistance. All patients underwent drug sensitivity testing (DST) to 13 commonly used anti-tubercular drugs using BACTEC MGIT-960 system. The drug sensitivity pattern of primary and secondary anti-tubercular drugs was recorded and compared.Results: The DST study revealed 110 (43.6%) cases of multi-drug resistant (MDR-resistance to both isoniazid and rifampicin) and 24 (9.5%) cases of non-MDR-TB spine. The widespread resistance was found for both isoniazid (91%) and rifampicin (85%), followed by streptomycin (61.9%). The least resistance was found for kanamycin, amikacin and capreomycin and no resistance found for clofazimine.Conclusion: The Xpert MTB/RIF assay is an efficient technique for the rapid diagnosis of spinal TB and suspected MDR-TB; however, it is recommended to do culture and DST in all patients with spinal TB to guide the selection of appropriate second-line drugs when required. In cases of non-availability of culture and DST, it is suggested to use data from large series such as this to plan the best empirical ATT regimen. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Introduction: Sternoclavicular joint tuberculosis is rare and has been presented in literature with few sporadic case reports or small case series. Rarity of the condition, nonspecific symptoms, difficulty to visualise the area on X-rays, and minimal clinical signs make diagnosis of sternoclavicular tuberculosis extremely difficult. Delay in diagnosis is therefore the common feature of all presented reports in literature. We here present our experience of treating 19 cases of sternoclavicular tuberculosis at our centre.Materials and Method: This is an observational study from 2010 to 2017 in a tertiary care referral hospital. All patients with clinical tenderness of sternoclavicular joint and shoulder joint pain of over three week duration were subjected to MRI. Patients who showed radiological lesions (radiography/MRI) were subjected to core biopsy under image guidance. A total of 26 patients had biopsy confirmed sternoclavicular tuberculosis (TB) during this period.Results: All patients had improvement in shoulder function after treatment completion. Mean CSS pre-treatment was 29 which improved to mean of 8 after 18 months of ATT. Eight patients had excellent results, seven good, three fair, and one patient poor result. High initial ESR, late commencement of ATT from initial symptoms, and surgery of the involved joint were considered poor prognostic factors.Discussion: Sternoclavicular tuberculosis is a rare disease with controversial etiology. Both haematogenous spread through suprascapular artery and contiguous spread through latent disease in apical lungs has been postulated. Delay in diagnosis is common to most reports in literature. Early MRI is useful in diagnosis of the lesion. The treatment for sternoclavicular joint in literature is controversial with proponents of both surgery and conservative management.Conclusion: Primary sternoclavicular tuberculosis is rare condition and requires a high index of suspicion for an early diagnosis. A focused sternoclavicular MRI and early biopsy may help in timely diagnosis. Early commencement of ATT has overall good clinical and functional results. [ABSTRACT FROM AUTHOR]

Drug resistance in Mycobacterium tuberculosis is relentlessly progressing while only a handful of novel drug candidates are developed. Here we describe a GFP-based high-throughput screening of 386,496 diverse compounds to identify putative tuberculosis drug candidates. In an exploratory analysis of the model organism M. bovis BCG and M. smegmatis and the subsequent screening of the main library, we identified 6354 compounds with anti-mycobacterial activity. These hit compounds were predominantly selective for mycobacteria while dozens had activity in the low μM range. We tested toxicity against the human monocyte/macrophage cell line THP-1 and elaborated activity against M. tuberculosis growing in liquid broth, under unique conditions such as non-replicating persistence or inhibition of M. tuberculosis residing in macrophages. Finally, spontaneous compound-resistant M. tuberculosis mutants were selected and subsequently analyzed by whole genome sequencing. In addition to compounds targeting the well-described proteins Pks13 and MmpL3, we identified two novel scaffolds targeting the bifunctional guanosine pentaphosphate synthetase/ polyribonucleotide nucleotidyltransferase GpsI, or interacting with the aminopeptidase PepB, a probable pro-drug activator. Key messages: A newly identified scaffold targets the bifunctional enzyme GpsI. The aminopeptidase PepB is interacting with a second novel scaffold. Phenotypic screenings regularly identify novel compounds targeting Pks13 and MmpL3. [ABSTRACT FROM AUTHOR]

A novel series of 2-(4-chlorobenzylamino)-4-(cyclohexylmethylamino)-pyrimidine-5-carboxamide derivatives are synthesized and their structures are confirmed by 1H and 13C NMR, and MS spectral data. The compounds are screened for their antitubercular activity, and those with aryl moiety 7o, 7q, and 7r demonstrate potent activity against Mycobacterium tuberculosis. Docking studies suggest a mode of interaction of the products with the binding site of enoyl-CoA hydratase demonstrating that the target compounds were potential anti-TB agents. [ABSTRACT FROM AUTHOR]

Increasing drug resistance in pathogens including Mycobacterium tuberculosis (MTB) has been ascribed to mutations in the known target genes. However, many of these drugs have multiple targets; some of which have not been identified so far. Understanding the mechanism of action of these drugs holds a great promise in better management of disease especially by drug-resistant strains. In this study, we report glutamate racemase (MurI), a crucial enzyme of phase I peptidoglycan (PG) biosynthesis pathway of MTB, as an additional target of ethambutol (EMB). The effect on EMB on the MurI protein at structural and functional level was studied using different spectroscopic, biochemical, and insilico approaches. Spectroscopic analysis revealed that EMB-modified protein undergoes conformational alterations. Furthermore, in vitro racemization studies of the MurI protein suggest that EMB decreases its functional activity. Docking studies revealed that EMB interacts with most of the active residues at the binding site and blocks the binding pocket. Overall, data suggests that EMB, a primary drug used for the treatment of tuberculosis (TB), acts as a competitive inhibitor of substrate for binding to mycobacterial MurI protein. The study also points out to our lacunae in understanding the site and mechanism of action of existing drugs. Furthermore, glutamate racemase is a conserved protein of the bacterial kingdom; therefore, ethambutol could be a promising candidate as a broad-spectrum antibiotic for many other bacterial diseases. [ABSTRACT FROM AUTHOR]

Abstract: Drug-resistant Mycobacterium tuberculosis and its high virulence new strains present a global health threat. The solution of this problem requires the development of new anti-tuberculosis drugs. Investigation of the genetic mechanisms associated with the development of multidrug resistant M. tuberculosis strains is the basis for the search for new biotargets of anti-tuberculosis drugs. To date, the molecular genetic relationships between genes controlling drug resistance and virulence remain poorly investigated and require special attention. In the present study, genetic mechanisms of interaction of genetic systems of drug resistance and virulence of M. tuberculosis are considered. [ABSTRACT FROM AUTHOR]

Expression of CD11, CD29, CD36, and DC-STAMP molecules by macrophages was analyzed in in vitro experiments. These molecules mediate cell fusion, one of the mechanisms underlying the formation of multinuclear macrophages. Macrophages were obtained from intact and BCG-infected male BALB/c mice. In intact cultures, multinuclear macrophages appeared primarily due to amitotic division of cell nuclei, while in macrophage cultures from infected mice, the process of cell fusion predominated. In intact macrophage cultures, bi- and multinuclear cells expressed primarily CD29 and CD36. In cultures from infected mice, macrophages expressing CD29 and DC-STAMP predominated, but bi- and multinuclear macrophages expressing CD11 and CD36 predominated over mononuclear ones. The study of macrophage fusion mechanism can be useful for understanding of this biological phenomenon as the mechanisms of delivery of M. tuberculosis and lysosomotropic anti-tuberculosis drugs into tuberculous granulomas to suppress M. tuberculosis persisting in macrophages and reduce the destructive potential of granulomas. [ABSTRACT FROM AUTHOR]

The article draws the attention of chemists to the literature data reporting the discovery of new targets for growth inhibition of Mycobacterium tuberculosis, namely, diterpene cyclase (Rv3377c) and tuberculosinol phosphatase (Rv3378c), which produce diterpenoids of tuberculosinols in the cell membrane of M. tuberculosis, and these diterpenoids ensure the pathogenicity and the virulence of M. tuberculosis. For the first time, by the example of diterpenoid of isosteviol, its binuclear derivatives, triterpenoid betulinic, oleanolic, and ursolic acids, it has been shown by the molecular docking method that the antitubercular activity of natural terpenoids is caused by their ability to bind to the active site of tuberculosinol phosphatase (Rv3378c) of M. tuberculosis. It is suggested that natural and semisynthetic terpenoids represent a promising platform for design of a new generation of antitubercular agents that affect this enzyme. [ABSTRACT FROM AUTHOR]

Novel phosphorylated derivatives of the diterpenoid isosteviol were synthesized and exhibited antituberculosis, antimicrobial, and anticancer activity. [ABSTRACT FROM AUTHOR]

Dihydropyrimidinethione podands, as well as podands containing 2-thienyl substituents have been synthesized via the multicomponent Biginelli reaction. Tuberculostatic activity of the novel podands was shown to depend on the polyether unit length. In particular, activity of dihydropyrimidinethione podands against laboratory strains of Mycobacterium tuberculosis, H37Rv, M. avium, M. terrae, and the clinical strain of multi-drug resistant M. tuberculosis (MDR), increases with a shortening of the polyether unit length. [ABSTRACT FROM AUTHOR]

A series of 2-aryl-4-((4-aryl-1 H-1,2,3-triazol-1-yl)methyl)thiazole derivatives ( 8a- p) have been synthesized. The structure of the newly synthesized compounds was determined by spectral analysis. The title compounds were screened for their preliminary antitubercular activity against Mycobacterium tuberculosis H37Ra (MTB, ATCC 25177) and Mycobacterium bovis BCG (BCG, ATCC 35743). Further, the synthesized compounds were screened for antimicrobial activity against standard Gram-negative bacteria Escherichia coli (NCIM 2576) and Pseudomonas flurescence (NCIM 2059) and Gram-positive bacteria Staphylococcus aureus (NCIM 2602) and Bacillus subtilis (NCIM 2162). Among all the synthesized compounds, 8a- c, f- h, m exhibited good activity against dormant M. bovis BCG strain. Compounds 8h, j exhibited good activity against all tested bacterial strains. All active compounds were screened for cytotoxicity and found inactive. Their high potency and promising antimycobacterial activity suggest that these compounds could serve as good leads for further optimization and development. [ABSTRACT FROM AUTHOR]

Emergence of various forms of resistant strains of Mycobacterium tuberculosis led to the exploration of drugs with novel mechanism of action. Recently econazole, an azole based antitubercular agent, attracted major attention for targeting mycobacterial cytochrome P450. In the present study, we designed novel 1,2,4-triazole derivatives based on econazole moiety and evaluated them for in vitro antitubercular activity against M. tuberculosis H37Rv and multi-drug resistant (MDR) strains of Mycobacterium. [ABSTRACT FROM AUTHOR]

Purpose: To compare titer reduction and delivery rate of active anti-tuberculosis bacteriophage (phage) D29 with three inhalation devices. Methods: Phage D29 lysate was amplified to a titer of 11.8 ± 0.3 log(pfu/mL) and diluted 1:100 in isotonic saline. Filters captured the aerosolized saline D29 preparation emitted from three types of inhalation devices: 1) vibrating mesh nebulizer; 2) jet nebulizer; 3) soft mist inhaler. Full-plate plaque assays, performed in triplicate at multiple dilution levels with the surrogate host Mycobacterium smegmatis, were used to quantify phage titer . Results: Respective titer reductions for the vibrating mesh nebulizer, jet nebulizer, and soft mist inhaler were 0.4 ± 0.1, 3.7 ± 0.1, and 0.6 ± 0.3 log(pfu/mL). Active phage delivery rate was significantly greater ( p < 0.01) for the vibrating mesh nebulizer (3.3x10 ± 0.8x10 pfu/min) than for the jet nebulizer (5.4x10 ± 1.3x10 pfu/min). The soft mist inhaler delivered 4.6x10 ± 2.0x10 pfu per 11.6 ± 1.6 μL ex-actuator dose. Conclusions: Delivering active phage requires a prudent choice of inhalation device. The jet nebulizer was not a good choice for aerosolizing phage D29 under the tested conditions, due to substantial titer reduction likely occurring during droplet production. The vibrating mesh nebulizer is recommended for animal inhalation studies requiring large amounts of D29 aerosol, whereas the soft mist inhaler may be useful for self-administration of D29 aerosol. [ABSTRACT FROM AUTHOR]

A highly efficient protocol for the synthesis of 1,2-bis(4-nitrophenyl)-1 H-benzo[ f]chromen-3-amine derivative has been illustrated by a one-pot three-component reaction of aromatic aldehydes, 4-nitrophenyl acetonitrile and β-naphthol by using p-toluenesulfonic acid (PTSA) as the catalyst. PTSA is a mild, efficient, inexpensive Lewis acid catalyst which smoothly catalyzes the reaction. The synthesized compounds were predicted on the basis of IR, HNMR, CNMR and mass analysis data. The entire synthesized compounds (B-1-B-11) were evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis HRV strain using microplate Alamar blue assay, which shows promising results and activity expressed as MIC in µg/ml. The results indicate that most of the compounds exhibit comparable activity with standards pyrazinamide, streptomycin and ciprofloxacin against M. tuberculosis. Compound B-11 showed the best result with MIC 1.6 µg/ml, compared with the standard used, which is the main scientific finding of this new series of chromene-based compounds. Graphical Abstract: [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) and sickle cell anaemia (SCA) may affect the same population of patients, particularly in Africa but also in high-TB incidence areas in developed countries. However, few data are available from children with SCA who develop TB. The aim of this study was to describe the clinical features and outcome of TB diagnosed in children with SCA. We conducted a retrospective, descriptive study in three referral centre of Sickle Cell Disease in Paris, France. We included 11 patients with SCA who develop TB. The median age at TB diagnosis was 11 years [7.5-14.5]. Two patients were asymptomatic and nine patients were symptomatic. Six patients had pulmonary TB (pulmonary, pleural and mediastinal lesions). Five patients had extrapulmonary TB (osteoarticular TB, hepatic TB, cervical and mediastinal TB). Mycobacterium tuberculosis was isolated in four of the 11 cases. All patients recovered after a median of 6 months of anti-TB treatment. The localisation of TB and outcome after treatment in our SCA patients were similar to the one observed in an age-and sex-matched control group of non-SCA patient with TB.Conclusion: despite the low number of patients included in our study, SCA does not seem to be a risk factor for severe TB. What is Known: • Tuberculosis (TB) remains a global health problem particularly in developing countries, and Sickle cell anaemia (SCA) is currently one of the most common genetic diseases in the world that mainly affects African populations. • Very few data are available on TB in SCA patients. What is New: • The features of TB in children with SCA seem to be comparable to those expected in general population, with favourable outcomes in response to standard treatment. • Monitoring the dosage of anti-TB treatments could be of interest because of the possible impact of SCA on drug metabolism. [ABSTRACT FROM AUTHOR]

Background: Nontuberculous mycobacteria (NTM) were considered saprophytic organisms for many years but now are recognized as human pathogens. Although humans are routinely exposed to NTM, the rate of clinical infection is low. Such infections usually occur in the elderly and in patients who are immunocompromised. However, there has been an increasing incidence in recent years of infections in immunocompetent hosts. NTM infections in immunocompetent individuals are secondary to direct inoculation either contamination from surgical procedures or penetrating injuries rather than hematogenous dissemination. Clinically and on histopathology, musculoskeletal infections caused by NTM resemble those caused by Mycobacterium tuberculosis but are mostly resistant to routine antituberculosis medicines. Materials and Methods: Six cases of NTM infection in immunocompetent hosts presenting to the department from 2004 to 2015 were included in study. Of which two cases (one patella and one humerus) of infection were following an open wound due to trauma while two cases (one hip and one shoulder) of infection were by inoculation following an intraarticular injection for arthrogram of the joint, one case was infection following arthroscopy of knee joint and one case (calcaneum) was infection following local injection for the treatment of plantar fasciitis. All patients underwent inaging and tissue diagnosis with samples being sent for culture, staining, and histopathology. Results: Clinical suspicion of NTM inoculation led to the correct diagnosis (four cases with culture positive and two cases with histopathological diagnosis). There treatment protocol for extrapulmonary NTM infection was radical surgical debridement and medical management based on drug sensitivity testing in culture positive cases. At a mean follow up of 3 years (range1-9 years) all patients had total remission and excellent results. Conclusions: Whenever a case of chronic granulomatous infection is encountered that does not respond to standard anti-tuberculous treatment, with a history of open trauma, surgical intervention, or injection as shown in this study, a possible NTM infection should be considered and managed appropriately. [ABSTRACT FROM AUTHOR]

Incorporation of rapid detection systems to identify mutations in M. tuberculosis complex that confer resistance to isoniazid and rifampicin has potentiated the knowledge of their distribution, given the geographical variability. We performed antibiograms of the 2,993 strains isolated in Galicia, Spain (2008-2013). In the strains resistant to isoniazid, a concentration of 0.4 mg/mL and MTBDRplus Genotype test (Hain Lifescience, Germany) were used. We found that 3.64 % of strains were resistant to isoniazid, while 0.43 % were resistant to isoniazid and rifampicin (multidrug resistant, MDR). The MTBDRplus test showed an overall sensitivity of 72.48 %, with 62.5 % sensitivity for non MDR isoniazid-resistant strains and 100 % sensitivity for MDR strains. The katG gene mutation was detected at codon 315 in 38.53 % of strains. The S315T mutation appeared in 61.54 % of MDR strains and 34.38 % of non-MDR strains. The 28.44 % had mutations in inhA, (93.55 % in C15T), and 38.46 % of MDR strains were mutated. In non-MDR strains, 37.50 % were wild-type, 35.42 % and 27.08 % had mutations in katG and inhA, respectively. The most frequent mutation in rpoβ was S531L (46.15 %). The 38.71 % and 41.9 % of strains with resistance to isoniazid and streptomycin had mutations in katG and inhA, respectively (2 strains with mutations in T8C and T8A). The distribution pattern of resistance among strains with high and low concentrations of isoniazid showed statistically significant differences in relation to the mutation in katG and wild-type. The sensitivity of the Genotype MTBDRplus test for non-MDR strains in our area was at the lower threshold described. [ABSTRACT FROM AUTHOR]

We have described a highly efficient, safer protocol for the synthesis of 5-arylidene-rhodanine conjugates catalyzed by Bronsted acidic ionic liquid [EtNH][HSO] in excellent yields. The protocol offers cost-effective, environmentally benign, solvent-free conditions and recycle-reuse of the catalyst. The synthesized 5-arylidene-rhodanine conjugates were characterized on the basis of H NMR, C NMR and HRMS spectral data. A series of 5-arylidene-rhodanine derivatives 3a-h, 4a-h were synthesized and evaluated for their in vitro antitubercular activity against dormant Mycobacterium tuberculosis H37Ra and M. bovis BCG strains. Moreover, compounds 3a, 3b, 3e, 3f, 3g, 3h and 4f exhibited good antitubercular activity and were also evaluated for anti-proliferative activity against MCF-7, A549 and HCT116 cell lines using modified MTT assay and found to be noncytotoxic. Compounds 3a-h and 4f were further screened for their antibacterial activity against four bacteria strains to assess their selectivity towards M. tuberculosis. Furthermore, in silico ADME prediction of all the tested compounds followed the criteria for orally active drug and, therefore, these compounds may have a good potential for eventual development as oral agents. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Purpose: Mycobacterium tuberculosis (Mtb) inhibits host defense mechanisms, including autophagy. We investigated particles containing rapamycin (RAP) alone or in combination with isoniazid (INH) and rifabutin (RFB) for: targeting lung macrophages on inhalation; inducing autophagy; and killing macrophage-resident Mtb and/or augmenting anti-tuberculosis (TB) drugs. Methods: PLGA and drugs were spray-dried. Pharmacokinetics, partial biodistribution (LC-MS/MS) and efficacy (colony forming units, qPCR, acid fast staining, histopathology) in mice following dry powder inhalation were evaluated. Results: Aerodynamic diameters of formulations were 0.7-4.7 μm. Inhaled particles reached deep lungs and were phagocytosed by alveolar macrophages, yielding AUC0-48 of 102 compared to 0.1 μg/ml × h obtained with equivalent intravenous dose. RAP particles induced more autophagy in Mtb-infected macrophages than solutions. Inhaled particles containing RAP alone in daily, alternate-day and weekly dosing regimens reduced bacterial burden in lungs and spleens, inducing autophagy and phagosome-lysosome fusion. Inhalation of particles containing RAP with INH and RFB cleared the lungs and spleens of culturable bacteria. Conclusions: Targeting a potent autophagy-inducing agent to airway and lung macrophages alone is feasible, but not sufficient to eliminate Mtb. Combination of macrophage-targeted inhaled RAP with classical anti-TB drugs contributes to restoring tissue architecture and killing Mtb. [ABSTRACT FROM AUTHOR]

Expression of CD11, CD29, CD36, and DC-STAMP molecules by macrophages was analyzed in in vitro experiments. These molecules mediate cell fusion, one of the mechanisms underlying the formation of multinuclear macrophages. Macrophages were obtained from intact and BCG-infected male BALB/c mice. In intact cultures, multinuclear macrophages appeared primarily due to amitotic division of cell nuclei, while in macrophage cultures from infected mice, the process of cell fusion predominated. In intact macrophage cultures, bi- and multinuclear cells expressed primarily CD29 and CD36. In cultures from infected mice, macrophages expressing CD29 and DC-STAMP predominated, but bi- and multinuclear macrophages expressing CD11 and CD36 predominated over mononuclear ones. The study of macrophage fusion mechanism can be useful for understanding of this biological phenomenon as the mechanisms of delivery of M. tuberculosis and lysosomotropic anti-tuberculosis drugs into tuberculous granulomas to suppress M. tuberculosis persisting in macrophages and reduce the destructive potential of granulomas. [ABSTRACT FROM AUTHOR]

Shikimate kinase of Mycobacterium tuberculosis is involved in the biosynthesis of aromatic amino acids through shikimate pathway. The enzyme is essential for the survival of M. tuberculosis and is absent from mammals, thus providing an excellent opportunity for identifying new chemical entities to combat tuberculosis with a novel mechanism of action. In this study, an antitubercular library of 1000 compounds was screened against M. tuberculosis shikimate kinase (MtSK). This effort led to the identification of 20 inhibitors, among which five promising leads exhibited half maximal inhibitory concentration (IC) values below 10 μM. The most potent inhibitor ('5631296') showed an IC value of 5.10 μM ± 0.6. The leads were further evaluated for the activity against multidrug-resistant (MDR)-TB, Gram-positive and Gram-negative bacterial strains, mode of action, docking simulations, and combinatorial study with three frontline anti-TB drugs. Compound '5491210' displayed a nearly synergistic activity with rifampicin, isoniazid, and ethambutol while compound '5631296' was synergistic with rifampicin. In vitro cytotoxicity against HepG2 cell line was evaluated and barring one compound; all were found to be non-toxic (SI > 10). In order to rule out mitochondrial toxicity, the promising inhibitors were also evaluated for cell cytotoxicity using galactose medium where compounds '5631296' and '5122752' appeared non-toxic. Upon comprehensive analysis, compound '5631296' was found to be the most promising MtSK inhibitor that was safe, synergistic with rifampicin, and bactericidal against M. tuberculosis. [ABSTRACT FROM AUTHOR]

Oral delamanid (Deltyba) is a useful addition to the treatment options currently available to treat patients with multidrug-resistant tuberculosis (MDR-TB). In the EU, it is indicated for use as part of an appropriate combination regimen in adults with MDR-TB when an effective treatment regimen cannot otherwise be composed due to resistance or tolerability. It exhibits potent antitubercular activity against drug-susceptible and -resistant strains of Mycobacterium tuberculosis. In a 3-month randomized control trial (2 months treatment + 1 month follow-up) in adults with MDR-TB, delamanid 100 mg twice daily + an optimized background regimen (OBR) improved 2-month sputum culture conversion rates to a significantly greater extent than placebo + OBR. In consecutive extension and follow-up studies, treatment with delamanid for ≥6 to 8 months was associated with higher rates of favourable outcomes and lower rates of unfavourable outcomes than treatment for ≤2 months. Delamanid was generally well tolerated in patients with MDR-TB. To reduce the potential risk of QT interval prolongation with delamanid, recommendations regarding monitoring and precautionary measures should be followed. [ABSTRACT FROM AUTHOR]

Pyrazinamide (PZA) is one the first line anti-tuberculosis drugs that require activation by the pyrazinamidase (PZase). Most PZA-resistant Mycobacterium tuberculosis strains have mutations in the pncA gene which encoding PZase that result in the reduction or loss of the enzyme activity. Herein, we have examined how various mutations, which have been found from the PZA-resistant M. t uberculosis strains in Iran, modify the PZase activity. To elucidate the possible role of these mutations, namely A143T (MUT1), L151S (MUT2), A143T/T168A/E173K (MUT3), in the bioactivity of the enzyme, the PZase and mutant genes were cloned, functionally expressed and biochemically and computationally characterized. In comparison to the PZase enzyme, the enzymatic efficiency of mutant enzymes was decreased, with MUT2 indicating the largest enzymatic efficiency reduction. Homology models of mutants were constructed based on the PZase X-ray crystal structure. Molecular modeling and substrate docking revealed that the wild-type has much stronger binding affinity to PZA than the mutants whereas MUT2 has the weakest binding affinity. In addition, the molecular dynamics simulations and the essential dynamics results illustrated that the positions of the 51st to 71st residues were more dynamics in MUT2 as compared to the other atoms in PZase, MUT1 and MUT3 which could decrease the K and k values of the enzymes. [ABSTRACT FROM AUTHOR]