920 resultados para Anti- Mycobacterium tuberculosis activity
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A reação em cadeia da polimerase usada para amplificação de uma seqüência interna de um fragmento previamente amplificado (nested-PCR) foi investigada como uma alternativa complementar a pesquisa de bacilos álcool ácido resistentes e a cultura do Mycobacterium tuberculosis em meio de Lowenstein-Jensen. Foram investigadas 144 amostras de escarro de pacientes suspeitos de tuberculose encaminhados ao Laboratório de Tuberculose do Instituto Evandro Chagas em Belém, no período de junho de 2002 a dezembro de 2003. Das 144 amostras, 121 foram caracterizadas como tuberculose, 119 foram positivas na cultura, 95 na baciloscopia e 128 na nested-PCR. A sensibilidade da nested-PCR foi 96% (116/121), enquanto a especificidade foi 48% (11/23). A nested-PCR poderá ser uma ferramenta complementar para o diagnóstico da tuberculose, pois apresenta sensibilidade equivalente à cultura, no entanto, necessita de maiores avaliações visando minimizar o número de resultados falso-positivos.
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Pós-graduação em Biociências e Biotecnologia Aplicadas à Farmácia - FCFAR
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Especialmente desenvolvido contra as micobactérias. O dito composto apresentando a composição e ser preparado pela reação entre Aspartame e nitrato de prata em meio neutro, possuindo a atividade bactericida contra as micobactérias a saber: Mycobacterium tuberculosis, Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium malmoense e Mycobacterium kansasii.
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Improved methods for the detection of Histoplasma capsulatum are needed in regions with limited resources in which the organism is endemic, where delayed diagnosis of progressive disseminated histoplasmosis (PDH) results in high mortality rates. We have investigated the use of a loop-mediated isothermal amplification (LAMP) assay to facilitate rapid inexpensive molecular diagnosis of this disease. Primers for LAMP were designed to amplify the Hcp100 locus of H. capsulatum. The sensitivity and limit of detection were evaluated using DNA extracted from 91 clinical isolates of known geographic subspecies, while the assay specificity was determined using DNA extracted from 50 other fungi and Mycobacterium tuberculosis. Urine specimens (n = 6) collected from HIV-positive individuals with culture- and antigen-proven histoplasmosis were evaluated using the LAMP assay. Specimens from healthy persons (n = 10) without evidence of histoplasmosis were used as assay controls. The Hcp100 LAMP assay was 100% sensitive and specific when tested with DNA extracted from culture isolates. The median limit of detection was <= 6 genomes (range, 1 to 300 genomes) for all except one geographic subspecies. The LAMP assay detected Hcp100 in 67% of antigen-positive urine specimens (4/6 specimens), and results were negative for Hcp100 in all healthy control urine specimens. We have shown that the Hcp100 LAMP assay is a rapid affordable assay that can be used to expedite culture confirmation of H. capsulatum in regions in which PDH is endemic. Further, our results indicate proof of the concept that the assay can be used to detect Histoplasma DNA in urine. Further evaluation of this assay using body fluid samples from a larger patient population is warranted.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Química - IBILCE
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Pós-graduação em Medicina Veterinária - FCAV
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Bacterial quorum sensing (QS) is a density dependent communication system that regulates the expression of certain genes including production of virulence factors in many pathogens. Bioactive plant extract/compounds inhibiting QS regulated gene expression may be a potential candidate as antipathogenic drug. In this study anti-QS activity of peppermint (Menthe piperita) oil was first tested using the Chromobacterium violaceum CVO26 biosensor. Further, the findings of the present investigation revealed that peppermint oil (PMO) at sub-Minimum Inhibitory Concentrations (sub-MICs) strongly interfered with acyl homoserine lactone (AHL) regulated virulence factors and biofilm formation in Pseudomonas aeruginosa and Aeromonas hydrophila. The result of molecular docking analysis attributed the QS inhibitory activity exhibited by PMO to menthol. Assessment of ability of menthol to interfere with QS systems of various Gram-negative pathogens comprising diverse AHL molecules revealed that it reduced the AHL dependent production of violacein, virulence factors, and biofilm formation indicating broad-spectrum anti-QS activity. Using two Escherichia colt biosensors, MG4/pKDT17 and pEAL08-2, we also confirmed that menthol inhibited both the las and pqs QS systems. Further, findings of the in vivo studies with menthol on nematode model Caenorhabditis elegans showed significantly enhanced survival of the nematode. Our data identified menthol as a novel broad spectrum QS inhibitor.
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Tuberculosis (TB) is an infectious disease caused by bacterium of the Mycobacterium genus, mainly by Mycobacterium tuberculosis (MTB). The World Health Organization aims to substantially reduce the number of cases in the coming years; however, the increased number of multidrug-resistant (MDR) and extremely drug-resistant (XDR) forms of the bacterium and the lack of treatment for latent tuberculosis are challenges to be overcome. In this review, we have identified the most potent compounds described in the literature during recent years with MIC values < 7 µM, low toxicity and a high selective index. In addition, emerging targets in MTB are presented to provide new perspectives for the discovery of new antitubercular drugs. This review aims to summarize the current advances in and promote insights into antitubercular drug discovery.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Introdução: Hanseníase e Tuberculose são enfermidades associadas à supressão da imunidade celular do tipo TH1. As manifestações clínicas da hanseníase são usualmente cutâneas e da tuberculose (Tbc) tegumento-pulmonares. O objetivo é demonstrar a presença de ambas as enfermidades no mesmo paciente. Relato do caso: Paciente masculino, 59 anos, em uso de prednisona 40mg/d há 6 meses devido a um quadro “alérgico”, com queixa de úlcera peri-anal dolorosa e sangrante. Ao exame apresentava úlcera fagedênica peri-anal e inguinal fistulizado e pápulas normocrômicas no antebraço. Histopatológico de lesão nodular e da úlcera mostra infiltrado granulomatoso com BAAR +,interpretado como hanseníase multibacilar. O tratamento não resultou em melhora das lesões inguinais e perianal. Novos exames demonstraram serem as lesões ulceradas causadas pelo Mycobacterium tuberculosis, por cultura, e as lesões pápulo-nodulares serem Mycobacterium leprae, por PCR. Tratamento para ambas foi eficaz. O M.leprae e M.tuberculosis são patógenos intracelulares obrigatórios e a defesa do hospedeiro está diretamente associada à imunidade celular. Mesmo em países endêmicos para ambas as enfermidades a associação das duas doenças é de ocorrência excepcional. O uso da corticoterapia utilizada para quadro alérgico (ENH) facilitou a ocorrência da Tbc. O caso relata a importância dos métodos auxiliares diagnósticos em caso de difícil interpretação clínica.
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Background: This paper addresses the prediction of the free energy of binding of a drug candidate with enzyme InhA associated with Mycobacterium tuberculosis. This problem is found within rational drug design, where interactions between drug candidates and target proteins are verified through molecular docking simulations. In this application, it is important not only to correctly predict the free energy of binding, but also to provide a comprehensible model that could be validated by a domain specialist. Decision-tree induction algorithms have been successfully used in drug-design related applications, specially considering that decision trees are simple to understand, interpret, and validate. There are several decision-tree induction algorithms available for general-use, but each one has a bias that makes it more suitable for a particular data distribution. In this article, we propose and investigate the automatic design of decision-tree induction algorithms tailored to particular drug-enzyme binding data sets. We investigate the performance of our new method for evaluating binding conformations of different drug candidates to InhA, and we analyze our findings with respect to decision tree accuracy, comprehensibility, and biological relevance. Results: The empirical analysis indicates that our method is capable of automatically generating decision-tree induction algorithms that significantly outperform the traditional C4.5 algorithm with respect to both accuracy and comprehensibility. In addition, we provide the biological interpretation of the rules generated by our approach, reinforcing the importance of comprehensible predictive models in this particular bioinformatics application. Conclusions: We conclude that automatically designing a decision-tree algorithm tailored to molecular docking data is a promising alternative for the prediction of the free energy from the binding of a drug candidate with a flexible-receptor.
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Central nervous system (CNS) tuberculosis (TB) is the most severe form of TB, characterized morphologically by brain granulomas and tuberculous meningitis (TBM). Experimental strategies for the study of the host-pathogen interaction through the analysis of granulomas and its intrinsic molecular mechanisms could provide new insights into the neuropathology of TB. To verify whether cerebellar mycobacterial infection induces the main features of the disease in human CNS and better understand the physiological mechanisms underlying the disease, we injected bacillus Calmette-Guerin (BCG) into the mouse cerebellum. BCG-induced CNS-TB is characterized by the formation of granulomas and TBM, a build up of bacterial loads in these lesions, and microglial recruitment into the lesion sites. In addition, there is an enhanced expression of signaling molecules such as nuclear factor-kappa B (NF-kappa B) and there is a presence of inducible nitric oxide synthase (iNOS) in the lesions and surrounding areas. This murine model of cerebellar CNS-TB was characterized by cellular and biochemical immune responses typically found in the human disease. This model could expand our knowledge about granulomas in TB infection of the cerebellum, and help characterize the physiological mechanisms involved with the progression of this serious illness that is responsible for killing millions people every year. (C) 2012 Elsevier B.V. All rights reserved.