Search results for " tuberculosis"
showing 10 items of 213 documents
Characterisation of rpsL, rrs and embB mutations associated with streptomycin and ethambutol resistance in Mycobacterium tuberculosis.
2003
In order to characterise molecular mechanisms of first-line drug resistance in Mycobacterium tuberculosis and to evaluate the use of molecular markers of resistance (gene point mutations), we analysed 66 multi-drug-resistant (MDR) isolates from Latvian tuberculosis patients. They were all resistant to rifampin (RIF), isoniazid (INH) and streptomycin (SM), and 33 were resistant to ethambutol (EMB). Enzymatic digestion by MboII and nucleotide sequencing of the rpsL gene fragment detected a single nucleotide substitution K43R in 40 (61%) of the 66 SM-resistant M. tuberculosis isolates. Of the other 26 SM-resistant isolates, 16 (24%) had mutations at positions 513A--C and 516C--T of the rrs gen…
Whole genome sequencing analysis of intrapatient microevolution in Mycobacterium tuberculosis: potential impact on the inference of tuberculosis tran…
2013
Background. It has been accepted that the infection by Mycobacterium tuberculosis (M. tuberculosis) can be more heterogeneous than considered. The emergence of clonal variants caused by microevolution events leading to population heterogeneity is a phenomenon largely unexplored. Until now, we could only superficially analyze this phenomenon by standard fingerprinting (RFLP and VNTR).Methods. In this study we applied whole genome sequencing for a more in-depth analysis of the scale of microevolution both at the intrapatient and interpatient scenarios.Results. We found that the amount of variation accumulated within a patient can be as high as that observed between patients along a chain of t…
Genomic determinants of speciation and spread of the Mycobacterium tuberculosis complex
2019
14 páginas, 6 figuras
Intestinal tuberculosis as a cause of chronic diarrhoea among patients with human immunodeficiency virus infection: report of two cases.
2001
In Western countries human immunodeficiency virus infection is considered the main risk factor of tuberculous disease, its incidence being 500 times higher in HIV-infected patients than in the general population. Despite the disease frequently present in these patients with extraintestinal manifestations, intestinal localization is rarely observed and often as a consequence of complications such as acute gastrointestinal bleeding or perforation. The diagnosis of intestinal tuberculosis is difficult and is often delayed due to the lack of specific signs and symptoms as well as the low sensitivity of routine methods. A review of the literature is made and personal experience in the diagnosis …
The zebrafish embryo as an in vivo model for screening nanoparticle-formulated lipophilic anti-tuberculosis compounds.
2021
ABSTRACT With the increasing emergence of drug-resistant Mycobacterium tuberculosis strains, new and effective antibiotics against tuberculosis (TB) are urgently needed. However, the high frequency of poorly water-soluble compounds among hits in high-throughput drug screening campaigns is a major obstacle in drug discovery. Moreover, in vivo testing using conventional animal TB models, such as mice, is time consuming and costly, and represents a major bottleneck in lead compound discovery and development. Here, we report the use of the zebrafish embryo TB model for evaluating the in vivo toxicity and efficacy of five poorly water-soluble nitronaphthofuran derivatives, which were recently id…
Nanocarriers for respiratory diseases treatment: Recent advances and current challenges
2014
Pulmonary delivery of locally-acting drugs encapsulated in nanocarriers provides several advantages for the treatment of respiratory diseases such as asthma, chronic obstructive pulmonary diseases, cystic fibrosis, tuberculosis and lung cancer. These advantages include, among others, sustained drug delivery to the lungs, reduced therapeutic dose and improved patient compliance. The aim of this review is to give an updated overview on recent advances recorded in the last few years in this field as well as on the major challenges still existing and that remain to be overcome before any clinical application. After an outline on the cellular and extracellular barriers affecting drug delivery to…
Quantifying transmission fitness costs of multi-drug resistant tuberculosis.
2021
As multi-drug resistant tuberculosis (MDR-TB) continues to spread, investigating the transmission potential of different drug-resistant strains becomes an ever more pressing topic in public health. While phylogenetic and transmission tree inferences provide valuable insight into possible transmission chains, phylodynamic inference combines evolutionary and epidemiological analyses to estimate the parameters of the underlying epidemiological processes, allowing us to describe the overall dynamics of disease spread in the population. In this study, we introduce an approach to Mycobacterium tuberculosis (M. tuberculosis) phylodynamic analysis employing an existing computationally efficient mod…
Immune characterization of the HBHA-specific response in Mycobacterium tuberculosis-infected patients with or without HIV infection.
2017
Introduction RD1-based Interferon-γ Release Assays (IGRAs) cannot distinguish latent from active tuberculosis (TB) disease. Conversely, a positive response to heparin-binding haemagglutinin (HBHA)-based IGRAs, among TB-infected subjects, correlates with Mycobacterium tuberculosis (Mtb) containment and low risk of TB progression. The aim of this study was to characterize HBHA-immune responses in HIV-infected and uninfected subjects with active TB or latent TB infection (LTBI). Methods 49 subjects were prospectively enrolled: 22 HIV-uninfected (13 TB, 9 LTBI) and 27 HIV-infected (12 HIV-TB, 15 HIV-LTBI). Whole blood and peripheral blood mononuclear cells were stimulated with HBHA and RD1 anti…
Predictors of therapy failure in newly diagnosed pulmonary tuberculosis cases in Beira, Mozambique.
2018
Abstract Objective Tuberculosis (TB) remains a major global health issue, ranking in the top ten causes of death worldwide. A deep understanding of factors influencing poor treatment outcomes may allow the development of additional treatment strategies, focused on the most vulnerable groups. Aims of the study were: (i) to evaluate the treatment outcome among TB subjects followed in an outpatient setting and (ii) to analyze factors associated with treatment failure in newly diagnosed patients with pulmonary TB in Beira, the second largest city of Mozambique. Results A total of 301 TB adult patients (32.6% females) were enrolled. Among them, 62 (20.6%) experienced a treatment failure over a 6…
Gene expression models based on a reference laboratory strain are bad predictors of Mycobacterium tuberculosis complex transcriptional diversity
2016
ABSTRACTSpecies of the Mycobacterium tuberculosis complex (MTBC) kill more people every year than any other infectious disease. As a consequence of its global distribution and parallel evolution with the human host the bacteria is not genetically homogeneous. The observed genetic heterogeneity has relevance at different phenotypic levels, from gene expression to epidemiological dynamics. However current systems biology datasets have focused in the laboratory reference strain H37Rv. By using large expression datasets testing the role of almost two hundred transcription factors, we have constructed computational models to grab the expression dynamics of Mycobacterium tuberculosis H37Rv genes.…