299 resultados para Bacillus tuberculosis.
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Multidrug and extensively drug resistant Mycobacterium tuberculosis are a threat to tuberculosis control programs. Genotyping methods, such as spoligotyping and MIRU-VNTR typing (Mycobacterial Interspersed Repetitive Units), are useful in monitoring potentially epidemic strains and estimating strain phylogenetic lineages and/or genotypic families. M. tuberculosis Latin American Mediterranean (LAM) family is a major worldwide contributor to tuberculosis (TB). LAM specific molecular markers, Ag85C(103) single nucleotide polymorphism (SNP) and RDRio long-sequence polymorphism (LSP), were used to characterize spoligotype signatures from 859 patient isolates from Portugal. LAM strains were found responsible for 57.7% of all tuberculosis cases. Strains with the RDRio deletion (referred to as RDRio) were estimated to represent 1/3 of all the strains and over 60% of the multidrug resistant (MDR) strains. The major spoligotype signature SIT20 belonging to the LAM1 RDRio sublineage, represented close to 1/5th of all the strains, over 20% of which were MDR. Analysis of published datasets according to stipulated 12 loci MIRU-VNTR RDRio signatures revealed that 96.3% (129/134) of MDR and extensively drug resistant (XDR) clusters were RDRio. This is the first report associating the LAM RDRio sublineage with MDR. These results are an important contribution to the monitoring of these strains with heightened transmission for future endeavors to arrest MDR-TB and XDR-TB. (c) 2012 Elsevier B.V. All rights reserved.
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Purpose: We compared and characterized the effects of intravesical bacillus Calmette-Guerin and/or staphylococcal enterotoxin B for nonmuscle invasive bladder cancer.Materials and Methods: A total of 75 female Fisher 344 rats were anesthetized. of the rats 15 received 0.3 ml saline (control) and 60 received 1.5 mg/kg MNU (N-methyl-n-nitrosourea) intravesically every other week for 6 weeks. The rats were divided into 5 groups. The MNU and control groups received 0.3 ml saline. The bacillus Calmette-Guerin group received 10(6) cfu bacillus Calmette-Guerin. The staphylococcal enterotoxin B group received 10 mu g/ml staphylococcal enterotoxin B. The bacillus Calmette-Guerin plus staphylococcal enterotoxin B group received the 2 treatments simultaneously. Each group was treated intravesically for 6 weeks. At 15 weeks all bladders were collected for histopathological and immunological evaluation, and Western blot.Results: Papillary carcinoma (pTa) and high grade intraepithelial neoplasia (carcinoma in situ) were more common in the MNU group. Papillary hyperplasia was more common in the bacillus Calmette-Guerin and enterotoxin groups. Flat hyperplasia was more common in the bacillus Calmette-Guerin plus enterotoxin group. No significant toxicity was observed. The apoptosis and cellular proliferation indexes decreased in the bacillus Calmette-Guerin, enterotoxin and bacillus Calmette-Guerin plus enterotoxin groups compared to the MNU group. Intensified vascular endothelial growth factor, matrix metalloproteinase-9, Ki-67 and insulin-like growth factor receptor-1 immunoreactivity was verified in the MNU group, moderate in the bacillus Calmette-Guerin and enterotoxin groups, and weak in the bacillus Calmette-Guerin plus enterotoxin and control groups. In contrast, intense endostatin immunoreactivity was verified in the control and bacillus Calmette-Guerin plus enterotoxin groups.Conclusions: Bacillus Calmette-Guerin and staphylococcal enterotoxin B showed similar anti-angiogenic effects. Bacillus Calmette-Guerin plus enterotoxin treatment had additional activity compared to that of monotherapy. It was more effective in restoring apoptosis and balancing cellular proliferation, and it correlated with increased endostatin, and decreased vascular endothelial growth factor, matrix metalloproteinase-9, Ki-67 and insulin-like growth factor receptor-1 reactivity.
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The diagnosis of tuberculosis is seriously hampered in the absence of standard biosafety laboratory facilities for specimen concentration and Mycobacterium tuberculosis culture. Within a laboratory twinning arrangement, heat-fixed direct smear and sediment from 74 bleach-processed and 20 non-processed specimens from Cumura Hospital, Guinea-Bissau, were sent to Lisbon for molecular evaluation of rifampicin resistance. Sequence analysis of a 369 base-pair ppoB locus detected 3.2% (3/94) resistant specimens. To our knowledge, this represents the first report on the molecular analysis of M. tuberculosis from bleach-processed sputum, an alternative to current diagnostic practice in low-resource settings.
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In the search for new therapeutic tools against tuberculosis two novel iron complexes, [Fe(L-H)3], with 3-aminoquinoxaline-2-carbonitrile N(1),N(4)-dioxide derivatives (L) as ligands, were synthesized, characterized by a combination of techniques, and in vitro evaluated. Results were compared with those previously reported for two analogous iron complexes of other ligands of the same family of quinoxaline derivatives. In addition, the complexes were studied by cyclic voltammetry and EPR spectroscopy. Cyclic voltammograms of the iron compounds showed several cathodic processes which were attributed to the reduction of the metal center (Fe(III)/Fe(II)) and the coordinated ligand. EPR signals were characteristic of magnetically isolated high-spin Fe(III) in a rhombic environment and arise from transitions between m(s) = +/- 1/2 (geff-9) or m(s) = +/- 3/2 (g(eff)similar to 4.3) states. Mossbauer experiments showed hyperfine parameters that are typical of high-spin Fe(III) ions in a not too distorted environment. The novel complexes showed in vitro growth inhibitory activity on Mycobacterium tuberculosis H(37)Rv (ATCC 27294), together with very low unspecific cytotoxicity on eukaryotic cells (cultured murine cell line J774). Both complexes showed higher inhibitory effects on M. tuberculosis than the "second-line" therapeutic drugs. (C) 2010 Elsevier B.V. All rights reserved.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The article examines how tuberculosis patients who were exiled to sanitarium-cities in the state of Sao Paulo reacted to the social representations assigned to them not only by the public at large but by medical workers as well. By evaluating memoirs and related documents from the perspective of the anthropology of disease and the diseased, it was possible to identify the network of signifieds created by the afflicted community.
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Actions to overcome a disease are dependant, essentially, on what is known about it. Procedures followed in the past were sometimes bizarre, but justified because of how little was known about the disease. The tuberculosis prechemotherapeutic age was somber due to the high levels of fatalities and morbidity. With the arrival of the chemotherapeutic treatment its prognosis has changed. Tuberculosis declined in the 50's and stabilized in the 80's. Nevertheless, it is back increasing alarming its numbers more than ever; probably because of some factors, among them, the public health system lack of attention and the government's policies, increasing in the migration to and from the endemic areas, development of drug multi-resistant cepa and also to the HIV infection. An universal antimycobacteria chemotherapy treatment is not accepted, maybe because of the number of drugs that are available. Modern chemotherapy, however, has an attack and a maintenance phases with the aim to eliminate the bacillus of fast and slow multiplication, respectively. The treatment period is long, when compared with other infectious diseases, that leads to the lack of compliance. In spite of the available resources in the fight against tuberculosis they seem insufficient to restrain the disease. This has forced the search for new chemotherapy alternatives to avoid strong come back of tuberculosis to the point of being called the 'white plague' well into the 21'st century.
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The survival and conjugation ability of sporogenic and asporogenic Bacillus thuringiensis strains were investigated in broth, in non-amended sterile clay soil monoculture and in mixed soil culture. The 75 kb pHT73 plasmid carrying an erythromycin resistance determinant and a cry1Ac gene was transferred in mating broth and soil microcosm. Survival of strains was assessed in soil monoculture and in mixed soil culture for up to 20 days. Sporogenic strains rapidly formed viable spores which were maintained until the end of the experiment. The asporogenic strains were no longer recovered after 8 days of incubation. This study shows that the environmental impact of asporogenic B. thuringiensis strains is lower than that of sporogenic B. thuringiensis strains. Thus, the use of asporogenic strains may significantly reduce any potential risk (gene transfer, soil and plant contamination) due to the dissemination of B. thuringiensis-based biopesticides in the environment. Copyright (C) 2000 Federation of European Microbiological Societies.
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The plasmid pHT409 that harbours the cryIA(a) gene for the production of a δ-endotoxin (crystal protein) from Bacillus thuringiensis was transferred into Bradyrhizobium sp. A conjugal transfer system aiming to introduce the plasmid into the Bradyrhizobium sp. host from colonies of an Escherichia coli donor strain (DH5α
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CONTEXT: Epidemiological studies have demonstrated higher frequencies of the O blood group and the non-secretor phenotype of ABH antigens among patients suffering from peptic ulcers. Since Helicobacter pylori has been established as the main etiological factor in this disease, controversies about the associations of the ABO and Lewis blood group phenotypes and secretor and non-secretor phenotypes in relation to susceptibility towards infection by this bacillus have been presented. OBJECTIVE: To verify the frequencies of ABO, Lewis blood group phenotypes, secretor and non-secretor phenotypes in patients infected or uninfected by H. pylori. DESIGN: Cross-sectional study. SETTING: Outpatient clinic. PARTICIPANTS: One hundred and twenty patients with dyspeptic symptoms who underwent endoscopy. MAIN MEASUREMENTS: ABO and Lewis blood group phenotypes were determined by a standard hemagglutination test and the secretor and non-secretor phenotypes were evaluated by saliva samples using the inhibitor hemagglutination test. RESULTS: The diagnosis of infection, made via breath and urea tests and confirmed using polymerase chain reaction (PCR) in gastric biopsy fragments, showed the presence of H. pylori in 61.7% of the patients and absence in 38.3%. The differences between the frequencies of the ABO blood group phenotypes among infected (A 27.0%; B 12.2%; AB 4.0% and O 56.8%) and uninfected patients (A 58.7%; B 13.0%; AB 4.3% and O 24.0%) were significant. The Lewis blood type, secretor and non-secretor phenotypes showed homogeneous distribution between the groups of patients analyzed. CONCLUSIONS: Our results suggest that the infection of H. pylori can be related to ABO blood groups but not to the Lewis blood group nor to secretor and non-secretor phenotypes. Copyright©2002, Associação Paulista de Medicina.
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Tuberculosis (TB) resurged in the late 1980s and now kills approximately 3 million people a year. The reemergence of tuberculosis as a public health threat has created a need to develop new anti-mycobacterial agents. The shikimate pathway is an attractive target for herbicides and anti-microbial agents development because it is essential in algae, higher plants, bacteria, and fungi, but absent from mammals. Homologs to enzymes in the shikimate pathway have been identified in the genome sequence of Mycobacterium tuberculosis. Among them, the shikimate kinase I encoding gene (aroK) was proposed to be present by sequence homology. Accordingly, to pave the way for structural and functional efforts towards anti-mycobacterial agents development, here we describe the molecular modeling of M. tuberculosis shikimate kinase that should provide a structural framework on which the design of specific inhibitors may be based. © 2002 Elsevier Science (USA). All rights reserved.
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The alkalophilic Bacillus circulans D1 was isolated from decayed wood. It produced high levels of extracellular cellulase-free xylanase. The enzyme was thermally stable up to 60°C, with an optimal hydrolysis temperature of 70°C. It was stable over a wide pH range (5.5-10.5), with an optimum pH at 5.5 and 80% of its activity at pH 9.0. This cellulase-free xylanase preparation was used to biobleach kraft pulp. Enzymatic treatment of kraft pulp decreased chlorine dioxide use by 23 and 37% to obtain the same kappa number (κ number) and brightness, respectively. Separation on Sephadex G-50 isolated three fractions with xylanase activity with distinct molecular weights.
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Currently, there are 8 million new cases and 2 million deaths annually from tuberculosis, and it is expected that a total of 225 million new cases and 79 million deaths will occur between 1998 and 2030. The reemergence of tuberculosis as a public health threat, the high susceptibility of HIV-infected persons, and the proliferation of multi-drug-resistant strains have created a need to develop new antimycobacterial agents. The existence of homologues to the shikimate pathway enzymes has been predicted by the determination of the genome sequence of Mycobacterium tuberculosis. We have previously reported the cloning and overexpression of M. tuberculosis aro A-encoded EPSP synthase in both soluble and active forms, without IPTG induction. Here, we describe the purification of M. tuberculosis EPSP synthase (mtEPSPS) expressed in Escherichia coli BL21(DE3) host cells. Purification of mtEPSPS was achieved by a one-step purification protocol using an anion exchange column. The activity of the homogeneous enzyme was measured by a coupled assay using purified shikimate kinase and purine nucleoside phosphorylase proteins. A total of 53 mg of homogeneous enzyme could be obtained from 1 L of LB cell culture, with a specific activity value of approximately 18 U mg-1. The results presented here provide protein in quantities necessary for structural and kinetic studies, which are currently underway in our laboratory. © 2002 Elsevier Science (USA). All rights reserved.
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Esophageal-pharyngeal fluids from 53 free-ranging marsh deer (Blastocerus dichotomus) captured for a research program in the state of Mato Grosso do Sul, Brazil, were assayed for tuberculosis. Total DNA was extracted, amplified by polymerase chain reaction using specific primers for Mycobacterium tuberculosis complex (M. tuberculosis, M. bovis, M. microti, and M. africanum), and observed by agarose gel electrophoresis stained with ethidium bromide. All samples were negative. This, along with necropsy and histopathology data, suggests that these animals are not shedding and probably do not have active disease.