Antimicrobial evaluation of quinones and heterocyclic compounds against mycobacterium marinum, M. kansasii and M. abscessus

The resistance to antimicrobials and biocides observed in mycobacteria which do not cause tuberculosis (MNT) determines the necessity to develop drugs. The present study evaluated the activity of naphthoquinones and heterocyclic derivatives obtained from lapachol against Mycobacterium kansasii, M. marinum, and M. abscessus, through the REMA method. It was observed that lapachol was inactive against the three mycobateria species, while β-lapachone and nor-β-lapachone showed activity only against M. marinum. The most active substances for M. kansasii were the derivates 2, 3, 7, and 11, in which compound 2 (CMI = 0.96 μM) was the most active. For M. marinum, 2, 11, and 14 were the most active, while against M. abcessus the compound 3 was the only active. The results showed a wide and diversified resistance spectrum among the species studied, which could be related to the molecular structure and position of the substituting groups, indicating the potentiality of these molecules as antimicrobial prototypes.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Genomics and epidemiology for gastric adenocarcinomas (GE4GAC): a Brazilian initiative to study gastric cancer

Abstract Gastric cancer (GC) is the fifth most common type of cancer worldwide with high incidences in Asia, Central, and South American countries. This patchy distribution means that GC studies are neglected by large research centers from developed countries. The need for further understanding of this complex disease, including the local importance of epidemiological factors and the rich ancestral admixture found in Brazil, stimulated the implementation of the GE4GAC project. GE4GAC aims to embrace epidemiological, clinical, molecular and microbiological data from Brazilian controls and patients with malignant and pre-malignant gastric disease. In this letter, we summarize the main goals of the project, including subject and sample accrual and current findings

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

Interplay between Mutations and Efflux in Drug Resistant Clinical Isolates of Mycobacterium tuberculosis

Numerous studies show efflux as a universal bacterial mechanism contributing to antibiotic resistance and also that the activity of the antibiotics subject to efflux can be enhanced by the combined use of efflux inhibitors. Nevertheless, the contribution of efflux to the overall drug resistance levels of clinical isolates of Mycobacterium tuberculosis is poorly understood and still is ignored by many. Here, we evaluated the contribution of drug efflux plus target-gene mutations to the drug resistance levels in clinical isolates of M. tuberculosis. A panel of 17 M. tuberculosis clinical strains were characterized for drug resistance associated mutations and antibiotic profiles in the presence and absence of efflux inhibitors. The correlation between the effect of the efflux inhibitors and the resistance levels was assessed by quantitative drug susceptibility testing. The bacterial growth/survival vs. growth inhibition was analyzed through the comparison between the time of growth in the presence and absence of an inhibitor. For the same mutation conferring antibiotic resistance, different MICs were observed and the different resistance levels found could be reduced by efflux inhibitors. Although susceptibility was not restored, the results demonstrate the existence of a broad-spectrum synergistic interaction between antibiotics and efflux inhibitors. The existence of efflux activity was confirmed by real-time fluorometry. Moreover, the efflux pump genes mmr, mmpL7, Rv1258c, p55, and efpA were shown to be overexpressed in the presence of antibiotics, demonstrating the contribution of these efflux pumps to the overall resistance phenotype of the M. tuberculosis clinical isolates studied, independently of the genotype of the strains. These results showed that the drug resistance levels of multi- and extensively-drug resistant M. tuberculosis clinical strains are a combination between drug efflux and the presence of target-gene mutations, a reality that is often disregarded by the tuberculosis specialists in favor of the almost undisputed importance of antibiotic target-gene mutations for the resistance in M. tuberculosis

Chemical composition and antimycobacterial activity of the essential oil from Anemia tomentosa var. anthriscifolia

Submitted by Repositório Arca ([email protected]) on 2019-04-24T16:24:13Z No. of bitstreams: 1 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)Approved for entry into archive by Janaína Nascimento ([email protected]) on 2020-01-09T14:23:43Z (GMT) No. of bitstreams: 2 ve_Pinto_Shaft_etal_INI_2009.pdf: 226907 bytes, checksum: e140b3e9ac4a344b679551c780ec157b (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)Made available in DSpace on 2020-01-09T14:23:43Z (GMT). No. of bitstreams: 2 ve_Pinto_Shaft_etal_INI_2009.pdf: 226907 bytes, checksum: e140b3e9ac4a344b679551c780ec157b (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Núcleo de Pesquisas de Produtos Naturais. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Núcleo de Pesquisas de Produtos Naturais. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Núcleo de Pesquisas de Produtos Naturais. Rio de Janeiro, RJ, Brasil.Embrapa Agroindústria de Alimentos. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio Grande. Laboratório de Micobactérias. Rio Grande, RS, Brasil .Universidade Federal do Rio Grande. Laboratório de Micobactérias. Rio Grande, RS, Brasil .Universidade Federal do Rio Grande. Laboratório de Micobactérias. Rio Grande, RS, Brasil .Fundação Oswaldo Cruz.Instituto de Pesquisa Clínica Evandro Chagas. Plataforma de Bioensaios II. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Faculdade de Farmácia. Departamento de Produtos Naturais e Alimentos. Rio de Janeiro, RJ, Brasil.The essential oil from Anemia tomentosa var. anthriscifolia showed in vitro activity against Mycobacterium tuberculosis (MIC 100 μg/ml) and therefore was characterized by gas chromatography (GC) and by gas chromatography coupled with mass spectrometry (GC-MS). The major constituents of this essential oil were triquinane sesquiterpenes: silphiperfol-6-ene (14.7%), (–)-epi-presilphiperfolan-1-ol (30.6%), presilphiperfol-7-ene (3.9%), cameroonan-7α-ol (4.4%), prenopsan-8-ol (1.9%) and presilphiperfolan-8-ol (8.3%), suggesting the existence of different chemotypes for this species. The essential oil was fractionated by column chromatography and its major constituent and fractions were assayed against Mycobacterium tuberculosis and M. smegmatis. (–)-epi-Presilphiperfolan-1-ol exhibited an MIC of 120 μg/ml against M. tuberculosis H37Rv

Interplay between Mutations and Efflux in Drug Resistant Clinical Isolates of Mycobacterium tuberculosis

Numerous studies show efflux as a universal bacterial mechanism contributing to antibiotic resistance and also that the activity of the antibiotics subject to efflux can be enhanced by the combined use of efflux inhibitors. Nevertheless, the contribution of efflux to the overall drug resistance levels of clinical isolates of Mycobacterium tuberculosis is poorly understood and still is ignored by many. Here, we evaluated the contribution of drug efflux plus target-gene mutations to the drug resistance levels in clinical isolates of M. tuberculosis. A panel of 17 M. tuberculosis clinical strains were characterized for drug resistance associated mutations and antibiotic profiles in the presence and absence of efflux inhibitors. The correlation between the effect of the efflux inhibitors and the resistance levels was assessed by quantitative drug susceptibility testing. The bacterial growth/survival vs. growth inhibition was analyzed through the comparison between the time of growth in the presence and absence of an inhibitor. For the same mutation conferring antibiotic resistance, different MICs were observed and the different resistance levels found could be reduced by efflux inhibitors. Although susceptibility was not restored, the results demonstrate the existence of a broad-spectrum synergistic interaction between antibiotics and efflux inhibitors. The existence of efflux activity was confirmed by real-time fluorometry. Moreover, the efflux pump genes mmr, mmpL7, Rv1258c, p55, and efpA were shown to be overexpressed in the presence of antibiotics, demonstrating the contribution of these efflux pumps to the overall resistance phenotype of the M. tuberculosis clinical isolates studied, independently of the genotype of the strains. These results showed that the drug resistance levels of multi- and extensively-drug resistant M. tuberculosis clinical strains are a combination between drug efflux and the presence of target-gene mutations, a reality that is often disregarded by the tuberculosis specialists in favor of the almost undisputed importance of antibiotic target-gene mutations for the resistance in M. tuberculosis.publishersversionpublishe

1,3-Azoles from ortho-naphthoquinones: Synthesis of aryl substituted imidazoles and oxazoles and their potent activity against Mycobacterium tuberculosis

Twenty-three naphthoimidazoles and six naphthoxazoles were synthesised and evaluated against susceptible and rifampicin- and isoniazid-resistant strains of Mycobacterium tuberculosis. Among all the compounds evaluated, fourteen presented MIC values in the range of 0.78 to 6.25 mu g/mL against susceptible and resistant strains of M. tuberculosis, Five structures were solved by X-ray crystallographic analysis. These substances are promising antimycobacterial prototypes. (C) 2012 Elsevier Ltd. All rights reserved.National Research Council of Brazil (CNPq)CNPq (National Council of Research of Brazil)CAPESCAPESUFALUFALUFRJUFRJFURGFURGUFMGUFMGPrograma Institucional de Auxilio a Pesquisa de Doutores Recem-Contratados-UFMG [08/2010]Programa Institucional de Auxilio a Pesquisa de Doutores RecemContratadosUFMGUniversidade Federal de Minas GeraisUniversidade Federal de Minas Gerais [PRPq-12/2011]FAPEMIG [APQ-04166-10]FAPEMI