Nově se do terapie tuberkulózy v dětském věku dostávají moderní léky, tablety rozpustné v ústech. léky jsou k dispozici buď v kombinované formě (dohromady izoniasid + rifampicin + pyrazinamid nebo izoniasid + rifampicin) nebo samostatně (izoniasid a etambutol). léčba je indikována převážně pro nejmladší věkové skupiny.
Contemporary pharmaceutical agents, specifically orodispersible tablets, are now entering the management of tuberculosis in children. the pharmaceuticals are available in two forms: either in combination (isoniaside+rifamp icin+pyrazinamide, isoniazid+rifampicin) or as monotherapy (isoniaside, ethambutol). the treatment is primarily indicated for the youngest age groups.
- MeSH
- Antitubercular Agents * administration & dosage pharmacology therapeutic use MeSH
- Administration, Oral MeSH
- Child MeSH
- Ethambutol administration & dosage pharmacology therapeutic use MeSH
- Isoniazid administration & dosage pharmacology therapeutic use MeSH
- Combined Modality Therapy * methods MeSH
- Dosage Forms MeSH
- Humans MeSH
- Rifampin administration & dosage pharmacology therapeutic use MeSH
- Tuberculosis diagnosis drug therapy MeSH
- Check Tag
- Child MeSH
- Humans MeSH
Apart from the SARS-CoV-2 virus, tuberculosis remains the leading cause of death from a single infectious agent according to the World Health Organization. As part of our long-term research, we prepared a series of hybrid compounds combining pyrazinamide, a first-line antitubercular agent, and 4-aminosalicylic acid (PAS), a second-line agent. Compound 11 was found to be the most potent, with a broad spectrum of antimycobacterial activity and selectivity toward mycobacterial strains over other pathogens. It also retained its in vitro activity against multiple-drug-resistant mycobacterial strains. Several structural modifications were attempted to improve the in vitro antimycobacterial activity. The δ-lactone form of compound 11 (11') had more potent in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv. Compound 11 was advanced for in vivo studies, where it was proved to be nontoxic in Galleria mellonella and zebrafish models, and it reduced the number of colony-forming units in spleens in the murine model of tuberculosis. Biochemical studies showed that compound 11 targets mycobacterial dihydrofolate reductases (DHFR). An in silico docking study combined with molecular dynamics identified a viable binding mode of compound 11 in mycobacterial DHFR. The lactone 11' opens in human plasma to its parent compound 11 (t1/2 = 21.4 min). Compound 11 was metabolized by human liver fraction by slow hydrolysis of the amidic bond (t1/2 = 187 min) to yield PAS and its starting 6-chloropyrazinoic acid. The long t1/2 of compound 11 overcomes the main drawback of PAS (short t1/2 necessitating frequent administration of high doses of PAS).
- MeSH
- Antitubercular Agents chemistry MeSH
- COVID-19 * MeSH
- Zebrafish MeSH
- Aminosalicylic Acid * pharmacology MeSH
- Lactones MeSH
- Humans MeSH
- Mycobacterium tuberculosis * MeSH
- Mice MeSH
- Pyrazinamide pharmacology MeSH
- SARS-CoV-2 MeSH
- Tuberculosis * drug therapy MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
OBJECTIVES: Rapidly diagnosing drug-resistant TB is crucial for improving treatment and transmission control. WGS is becoming increasingly accessible and has added value to the diagnosis and treatment of TB. The aim of the study was to perform WGS to determine the rate of false-positive results of phenotypic drug susceptibility testing (pDST) and characterize the molecular mechanisms of resistance and transmission of mono- and polyresistant Mycobacterium (M.) tuberculosis. METHODS: WGS was performed on 53 monoresistant and 25 polyresistant M. tuberculosis isolates characterized by pDST. Sequencing data were bioinformatically processed to infer mutations encoding resistance and determine the origin of resistance and phylogenetic relationship between isolates studied. RESULTS: The data showed the variable sensitivity and specificity of WGS in comparison with pDST as the gold standard: isoniazid 92.7% and 92.3%; streptomycin 41.9% and 100.0%; pyrazinamide 15% and 94.8%; and ethambutol 75.0% and 98.6%, respectively. We found novel mutations encoding resistance to streptomycin (in gidB) and pyrazinamide (in kefB). Most isolates belonged to lineage 4 (80.1%) and the overall clustering rate was 11.5%. We observed lineage-specific gene variations encoding resistance to streptomycin and pyrazinamide. CONCLUSIONS: This study highlights the clinical potential of WGS in ruling out false-positive drug resistance following phenotypic or genetic drug testing, and recommend this technology together with the WHO catalogue in designing an optimal individualized treatment regimen and preventing the development of MDR TB. Our results suggest that resistance is primarily developed through spontaneous mutations or selective pressure.
- Publication type
- Journal Article MeSH
Tuberculosis is the number one killer of infectious diseases caused by a single microbe, namely Mycobacterium tuberculosis (Mtb). The success rate of curing this infection is decreasing due to emerging antimicrobial resistance. Therefore, novel treatments are urgently needed. As an attempt to develop new antituberculars effective against both drugs-sensitive and drug-resistant Mtb, we report the synthesis of a novel series inspired by combining fragments from the first-line agents isoniazid and pyrazinamide (series I) and isoniazid with the second-line agent 4-aminosalicylic acid (series II). We identified compound 10c from series II with selective, potent in vitro antimycobacterial activity against both drug-sensitive and drug-resistant Mtb H37Rv strains with no in vitro or in vivo cytotoxicity. In the murine model of tuberculosis, compound 10c caused a statistically significant decrease in colony-forming units (CFU) in spleen. Despite having a 4-aminosalicylic acid fragment in its structure, biochemical studies showed that compound 10c does not directly affect the folate pathway but rather methionine metabolism. In silico simulations indicated the possibility of binding to mycobacterial methionine-tRNA synthetase. Metabolic study in human liver microsomes revealed that compound 10c does not have any known toxic metabolites and has a half-life of 630 min, overcoming the main drawbacks of isoniazid (toxic metabolites) and 4-aminosalicylic acid (short half-life).
- MeSH
- Antitubercular Agents chemistry MeSH
- Isoniazid pharmacology MeSH
- Aminosalicylic Acid * pharmacology MeSH
- Humans MeSH
- Methionine MeSH
- Microbial Sensitivity Tests MeSH
- Mycobacterium tuberculosis * MeSH
- Mice MeSH
- Tuberculosis * drug therapy microbiology MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
BACKGROUND: Tuberculosis (TBC) in solid organ transplant recipients represents a severe complication. The incidence among transplant recipients is higher than in the general population, and the diagnosis and treatment remain challenging. We present a case of active disseminated tuberculosis in a kidney transplant recipient treated with an anti-CD40 monoclonal antibody, who had been previously exposed to an active form of the disease, but latent tuberculosis (LTBI) was repeatedly ruled out prior to transplantation. To the best of our knowledge, no other case has been reported in a patient treated with the anti-CD40 monoclonal antibody. CASE PRESENTATION: A 49-year-old patient, 1.5 years after primary kidney transplantation, presented with vocal cord problems, a dry irritating cough, and a sore throat. A detailed investigation, including a high-resolution chest CT scan, revealed the diagnosis of disseminated tuberculosis. The antituberculosis treatment consisting of rifampicin, isoniazid, pyrazinamide, and ethambutol was started immediately. The patient's condition became complicated by relapsing diarrhoea. The colonoscopy revealed a circular stenosis above Bauhin's valve. Microscopical findings showed active colitis and vaguely formed collections of epithelioid macrophages without fully developed caseous granulomas and were consistent with the clinical diagnosis of tuberculosis. The antituberculosis treatment was subsequently enhanced by moxifloxacin and led to a great improvement in the patient's condition. CONCLUSION: In this case, false negativity of interferon-γ release assays and possibly higher risk for intracellular infections in patients on costimulatory signal blockers are discussed.
- MeSH
- Antitubercular Agents therapeutic use MeSH
- Middle Aged MeSH
- Humans MeSH
- Antibodies, Monoclonal therapeutic use MeSH
- Transplant Recipients MeSH
- Antineoplastic Agents * MeSH
- Kidney Transplantation * adverse effects MeSH
- Tuberculosis * diagnosis drug therapy epidemiology MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Publication type
- Journal Article MeSH
- Case Reports MeSH
- Research Support, Non-U.S. Gov't MeSH
The emergence and spread of resistant tuberculosis (TB) pose a threat to public health, so it is necessary to diagnose the drug-resistant forms in a clinically short time frame and closely monitor their transmission. In this study, we carried out a first whole genome sequencing (WGS)-based analysis of multidrug resistant (MDR) M. tuberculosis strains to explore the phylogenetic lineages diversity, drug resistance mechanisms, and ongoing transmission chains within the country. In total, 65 isolates phenotypically resistant to at least rifampicin and isoniazid collected in the Czech Republic in 2005-2020 were enrolled for further analysis. The agreement of the results obtained by WGS with phenotypic drug susceptibility testing (pDST) in the determination of resistance to isoniazid, rifampicin, pyrazinamide, streptomycin, second-line injectables and fluoroquinolones was more than 80%. Phylogenetic analysis of WGS data revealed that the majority of MDR M. tuberculosis isolates were the Beijing lineage 2.2.1 (n = 46/65; 70.8%), while the remaining strains belonged to Euro-American lineage. Cluster analysis with a predefined cut-off distance of less than 12 single nucleotide polymorphisms between isolates showed 19 isolates in 6 clusters (clustering rate 29.2%), located mainly in the region of the capital city of Prague. This study highlights the utility of WGS as a high-resolution approach in the diagnosis, characterization of resistance patterns, and molecular-epidemiological analysis of resistant TB in the country.
- MeSH
- Antitubercular Agents pharmacology therapeutic use MeSH
- Phylogeny MeSH
- Genotype MeSH
- Isoniazid MeSH
- Humans MeSH
- Microbial Sensitivity Tests MeSH
- Drug Resistance, Multiple, Bacterial genetics MeSH
- Tuberculosis, Multidrug-Resistant * diagnosis drug therapy epidemiology MeSH
- Mutation MeSH
- Mycobacterium tuberculosis * MeSH
- Rifampin MeSH
- Whole Genome Sequencing methods MeSH
- Tuberculosis * drug therapy MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Czech Republic MeSH
Human cytosolic prolyl-tRNA synthetase (HcProRS) catalyses the formation of the prolyl-tRNAPro, playing an important role in protein synthesis. Inhibition of HcProRS activity has been shown to have potential benefits in the treatment of fibrosis, autoimmune diseases and cancer. Recently, potent pyrazinamide-based inhibitors were identified by a high-throughput screening (HTS) method, but no further elaboration was reported. The pyrazinamide core is a bioactive fragment found in numerous clinically validated drugs and has been subjected to various modifications. Therefore, we applied a virtual screening protocol to our in-house library of pyrazinamide-containing small molecules, searching for potential novel HcProRS inhibitors. We identified a series of 3-benzylaminopyrazine-2-carboxamide derivatives as positive hits. Five of them were confirmed by a thermal shift assay (TSA) with the best compounds 3b and 3c showing EC50 values of 3.77 and 7.34 µM, respectively, in the presence of 1 mM of proline (Pro) and 3.45 µM enzyme concentration. Co-crystal structures of HcProRS in complex with these compounds and Pro confirmed the initial docking studies and show how the Pro facilitates binding of the ligands that compete with ATP substrate. Modelling 3b into other human class II aminoacyl-tRNA synthetases (aaRSs) indicated that the subtle differences in the ATP binding site of these enzymes likely contribute to its potential selective binding of HcProRS. Taken together, this study successfully identified novel HcProRS binders from our anti-tuberculosis in-house compound library, displaying opportunities for repurposing old drug candidates for new applications such as therapeutics in HcProRS-related diseases.
- MeSH
- Adenosine Triphosphate metabolism MeSH
- Amino Acyl-tRNA Synthetases antagonists & inhibitors MeSH
- Biological Assay methods MeSH
- Enzyme Inhibitors chemistry isolation & purification pharmacology MeSH
- Protein Conformation MeSH
- Crystallography, X-Ray MeSH
- Humans MeSH
- Ligands MeSH
- Models, Molecular MeSH
- Computer Simulation * MeSH
- Pyrazinamide chemistry MeSH
- Binding Sites MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
