Base de dados : LILACS
Pesquisa : B03.510.024 [Categoria DeCS]
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Id: biblio-839352
Autor: Dalitz, Camila de Araújo; Porsani, Mariana Vieira; Figel, Izabel Cristina; Pimentel, Ida C; Dalzoto, Patrícia R.
Título: Potential for biocontrol of melanized fungi by actinobacteria isolated from intertidal region of Ilha Do Mel, Paraná, Brazil
Fonte: Braz. j. microbiol;48(1):32-36, Jan.-Mar. 2017. tab, graf.
Idioma: en.
Resumo: Abstract Actinobacteria occur in many environments and have the capacity to produce secondary metabolites with antibiotic potential. Identification and taxonomy of actinobacteria that produce antimicrobial substances is essential for the screening of new compounds, and sequencing of the 16S region of ribosomal DNA (rDNA), which is conserved and present in all bacteria, is an important method of identification. Melanized fungi are free-living organisms, which can also be pathogens of clinical importance. This work aimed to evaluate growth inhibition of melanized fungi by actinobacteria and to identify the latter to the species level. In this study, antimicrobial activity of 13 actinobacterial isolates from the genus Streptomyces was evaluated against seven melanized fungi of the genera Exophiala, Cladosporium, and Rhinocladiella. In all tests, all actinobacterial isolates showed inhibitory activity against all isolates of melanized fungi, and only one actinobacterial isolate had less efficient inhibitory activity. The 16S rDNA region of five previously unidentified actinobacterial isolates from Ilha do Mel, Paraná, Brazil, was sequenced; four of the isolates were identified as Streptomyces globisporus subsp. globisporus, and one isolate was identified as Streptomyces aureus. This work highlights the potential of actinobacteria with antifungal activity and their role in the pursuit of novel antimicrobial substances.
Descritores: Actinobacteria/fisiologia
Fungos/fisiologia
Antibiose
-Filogenia
Streptomyces/classificação
Streptomyces/genética
Brasil
RNA Ribossômico 16S/genética
Actinobacteria/isolamento & purificação
Actinobacteria/classificação
Actinobacteria/genética
Responsável: BR1.1 - BIREME


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Id: biblio-974282
Autor: Santos, Alexandra de Andrade; Silveira, Joaquim Albenísio Gomes da; Guilherme, Eliezer de Araujo; Bonifacio, Aurenivia; Rodrigues, Artenisa Cerqueira; Figueiredo, Márcia do Vale Barreto.
Título: Changes induced by co-inoculation in nitrogen-carbon metabolism in cowpea under salinity stress
Fonte: Braz. j. microbiol;49(4):685-694, Oct.-Dec. 2018. tab, graf.
Idioma: en.
Resumo: ABSTRACT To mitigate the deleterious effects of abiotic stress, the use of plant growth-promoting bacteria along with diazotrophic bacteria has been increasing. The objectives of this study were to investigate the key enzymes related to nitrogen and carbon metabolism in the biological nitrogen fixation process and to elucidate the activities of these enzymes by the synergistic interaction between Bradyrhizobium and plant growth-promoting bacteria in the absence and presence of salt stress. Cowpea plants were cultivated under axenic conditions, inoculated with Bradyrhizobium and co-inoculated with Bradyrhizobium sp. and Actinomadura sp., Bradyrhizobium sp. and Bacillus sp., Bradyrhizobium sp. and Paenibacillus graminis, and Bradyrhizobium sp. and Streptomycessp.; the plants were also maintained in the absence (control) and presence of salt stress (50 mmolL-1 NaCl). Salinity reduced the amino acids, free ammonia, ureides, proteins and total nitrogen content in nodules and increased the levels of sucrose and soluble sugars. The co-inoculations responded differently to the activity of glutamine synthetase enzymes under salt stress, as well as glutamate synthase, glutamate dehydrogenase aminating, and acid invertase in the control and salt stress. Considering the development conditions of this experiment, co-inoculation with Bradyrhizobium sp. and Bacillus sp. in cowpea provided better symbiotic performance, mitigating the deleterious effects of salt stress.
Descritores: Carbono/metabolismo
Cloreto de Sódio/metabolismo
Vigna/metabolismo
Nitrogênio/metabolismo
-Microbiologia do Solo
Cloreto de Sódio/análise
Actinobacteria/fisiologia
Raízes de Plantas/crescimento & desenvolvimento
Raízes de Plantas/metabolismo
Raízes de Plantas/microbiologia
Bradyrhizobium/fisiologia
Inoculantes Agrícolas/fisiologia
Vigna/crescimento & desenvolvimento
Vigna/microbiologia
FRONTAL LOBE0
Aminoácidos/metabolismo
Fixação de Nitrogênio
Responsável: BR1.1 - BIREME


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Id: biblio-1008381
Autor: Xu, Guojing; Li, Dongwei; Jiao, Binquan; Li, Dou; Yin, Yajie; Lun, Limei; Zhao, Ziqiang; Li, Shan.
Título: Biomineralization of a calcifying ureolytic bacterium Microbacterium sp. GM-1
Fonte: Electron. j. biotechnol;25:21-27, ene. 2017. ilus, graf, tab.
Idioma: en.
Projeto: Natural Science Foundation of China; . Chongqing Science & Technology Commission.
Resumo: Background: Biomineralization is a significant process performed by living organisms in which minerals are produced through the hardening of biological tissues. Herein, we focus on calcium carbonate precipitation, as part of biomineralization, to be used in applications for environmental protection, material technology, and other fields. A strain GM-1, Microbacterium sp. GM-1, isolated from active sludge, was investigated for its ability to produce urease and induce calcium carbonate precipitation in a metabolic process. Results: It was discovered that Microbacterium sp. GM-1 resisted high concentrations of urea up to 60 g/L. In order to optimize the calcification process of Microbacterium sp. GM-1, the concentrations of Ni2+ and urea, pH value, and culture time were analyzed through orthogonal tests. The favored calcite precipitation culture conditions were as follows: the concentration of Ni2+ and urea were 50 µM and 60 g/L, respectively, pH of 10, and culture time of 96 h. Using X-ray diffraction analysis, the calcium carbonate polymorphs produced by Microbacterium sp. GM-1 were proven to be mainly calcite. Conclusions: The results of this research provide evidence that Microbacterium sp. GM-1 can biologically induce calcification and suggest that strain GM-1 may play a potential role in the synthesis of new biominerals and in bioremediation or biorecovery.
Descritores: Actinobacteria/metabolismo
FRONTAL BONEABDOMINAL INJURIES
-Precipitação Química
Ureia/metabolismo
Calcificação Fisiológica
Carbonato de Cálcio/metabolismo
Actinobacteria/isolamento & purificação
Actinobacteria/química
Hidrólise
Níquel/metabolismo
Responsável: CL1.1 - Biblioteca Central


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Id: biblio-889233
Autor: Qin, Wei; Fan, Fuqiang; Zhu, Yi; Huang, Xiaolong; Ding, Aizhong; Liu, Xiang; Dou, Junfeng.
Título: Anaerobic biodegradation of benzo(a)pyrene by a novel Cellulosimicrobium cellulans CWS2 isolated from polycyclic aromatic hydrocarbon-contaminated soil
Fonte: Braz. j. microbiol;49(2):258-268, Apr.-June 2018. graf.
Idioma: en.
Projeto: National Natural Science Foundation of China; . Fundamental Research Funds for the Central Universities.
Resumo: Abstract Cellulosimicrobium cellulans CWS2, a novel strain capable of utilizing benzo(a)pyrene (BaP) as the sole carbon and energy source under nitrate-reducing conditions, was isolated from PAH-contaminated soil. Temperature and pH significantly affected BaP biodegradation, and the strain exhibited enhanced biodegradation ability at temperatures above 30 °C and between pH 7 and 10. The highest BaP removal rate (78.8%) was observed in 13 days when the initial BaP concentration was 10 mg/L, and the strain degraded BaP at constant rate even at a higher concentration (50 mg/L). Metal exposure experimental results illustrated that Cd(II) was the only metal ion that significantly inhibited biodegradation of BaP. The addition of 0.5 and 1.0 g/L glucose enhanced BaP biodegradation, while the addition of low-molecular-weight organic acids with stronger acidity reduced BaP removal rates during co-metabolic biodegradation. The addition of phenanthrene and pyrene, which were degraded to some extent by the strain, showed no distinct effect on BaP biodegradation. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that the five rings of BaP opened, producing compounds with one to four rings which were more bioavailable. Thus, the strain exhibited strong BaP degradation capability and has great potential in the remediation of BaP-/PAH-contaminated environments.
Descritores: Microbiologia do Solo
Poluentes do Solo/metabolismo
Benzo(a)pireno/metabolismo
Actinobacteria/isolamento & purificação
Actinobacteria/metabolismo
-Temperatura Ambiente
Cádmio/metabolismo
Carbono/metabolismo
Ácidos Carboxílicos/metabolismo
Biotransformação
Actinobacteria/classificação
Meios de Cultura/química
Inibidores Enzimáticos/metabolismo
Glucose/metabolismo
Concentração de Íons de Hidrogênio
Anaerobiose
Cromatografia Gasosa-Espectrometria de Massas
Responsável: BR1.1 - BIREME


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Id: biblio-889185
Autor: Muthukamalam, Santhakumar; Sivagangavathi, Sivalingam; Dhrishya, Dharmapal; Sudha Rani, Sadras.
Título: Characterization of dioxygenases and biosurfactants produced by crude oil degrading soil bacteria
Fonte: Braz. j. microbiol;48(4):637-647, Oct.-Dec. 2017. tab, graf.
Idioma: en.
Projeto: UGC.
Resumo: ABSTRACT Role of microbes in bioremediation of oil spills has become inevitable owing to their eco friendly nature. This study focused on the isolation and characterization of bacterial strains with superior oil degrading potential from crude-oil contaminated soil. Three such bacterial strains were selected and subsequently identified by 16S rRNA gene sequence analysis as Corynebacterium aurimucosum, Acinetobacter baumannii and Microbacterium hydrocarbonoxydans respectively. The specific activity of catechol 1,2 dioxygenase (C12O) and catechol 2,3 dioxygenase (C23O) was determined in these three strains wherein the activity of C12O was more than that of C23O. Among the three strains, Microbacterium hydrocarbonoxydans exhibited superior crude oil degrading ability as evidenced by its superior growth rate in crude oil enriched medium and enhanced activity of dioxygenases. Also degradation of total petroleum hydrocarbon (TPH) in crude oil was higher with Microbacterium hydrocarbonoxydans. The three strains also produced biosurfactants of glycolipid nature as indicated d by biochemical, FTIR and GCMS analysis. These findings emphasize that such bacterial strains with superior oil degrading capacity may find their potential application in bioremediation of oil spills and conservation of marine and soil ecosystem.
Descritores: Poluentes do Solo/metabolismo
Tensoativos/metabolismo
Proteínas de Bactérias/metabolismo
Petróleo/microbiologia
Actinobacteria/metabolismo
Corynebacterium/metabolismo
Acinetobacter baumannii/metabolismo
Dioxigenases/metabolismo
-Filogenia
Microbiologia do Solo
Tensoativos/química
Proteínas de Bactérias/genética
Biodegradação Ambiental
Petróleo/análise
Poluição por Petróleo/análise
Actinobacteria/crescimento & desenvolvimento
Actinobacteria/enzimologia
Actinobacteria/genética
Corynebacterium/crescimento & desenvolvimento
Corynebacterium/enzimologia
Corynebacterium/genética
Acinetobacter baumannii/crescimento & desenvolvimento
Acinetobacter baumannii/enzimologia
Acinetobacter baumannii/genética
Dioxigenases/genética
Índia
Responsável: BR1.1 - BIREME


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Id: biblio-965726
Autor: Naine, S Jemimah; Devi, C Subathra; Mohanasrinivasan, V.
Título: In vitro thrombolytic potential of bioactive compounds from marine Streptomyces sp. VITJS4 / Potencial trombolítico in vitro de compostos bioativos de Streptomyces marinhos sp. VITJS4
Fonte: Biosci. j. (Online);32(5):1314-1323, sept./oct 2016. ilus, tab, graf.
Idioma: en.
Resumo: The most practical approach to reduce morbidity and mortality of coronary heart disease (CHD) is to delay the process of thrombus by usage of clot-dissolving agents. The necessities of such safer compounds are to be critically examined for thrombolytic activity especially, from marine sources. Thrombolytic agents have been investigated as a possible treatment for thrombus. The aim of this study was to investigate the in vitro thrombolytic potential of Streptomyces sp.VITJS4 (NCIM No. 5574); (ACC No: JQ234978.1) active compounds. The fibrin degradation revealed a clear transparent zone of clearance with 500µg/mL concentration showing 24mm hydrolysis. The thrombolytic effect of Streptomyces sp.VITJS4 compounds was also demonstrated in vitro clot lysis assay where The percent of thrombolysis by the crude extract showed 90±1.7% at the concentration of 1000µg/mL, whereas percent of thrombolysis by streptokinase was found 100± 00%%. The bioactive compounds were further studied for spectrophotometric analysis. The UV-VIS profile showed different peaks ranging from 400-700 nm with different absorption respectively. The data confirmed the presence of both analogues with absorption maxima at 210 and 310 nm. A sensitive method using LC-MS technique was optimized for the separation and identification of bioactive metabolites which was indicated by the fingerprints. The results of the LC-MS analysis provided different peaks determining the presence of compounds with different therapeutic activities. The current study refers the bioactive compound as impressive thrombolytic agent for further laboratory study. Further studies should be conducted to ensure the efficacy and safety of different concentration of bioactive compounds for drug development. Hence the results reported perhaps useful for the discovery of novel thrombolytic drugs from marine origin.

A abordagem mais prática para reduzir a morbidade e a mortalidade da doença arterial coronariana (CHD, do inglês coronary heart disease) consiste em retardar o processo de trombo através da utilização de agentes de dissolução de coágulos. As necessidades de tais compostos mais seguros devem ser criticamente examinadas para a atividade trombolítica, especialmente de fontes marinhas. Agentes trombolíticos tem sido estudados como um possível tratamento para o trombo. O objetivo deste estudo foi investigar o potencial trombolítico in vitro dos compostos ativos do Streptomyces sp.VITJS4 (NCIM No. 5574); (ACC No: JQ234978.1). A degradação da fibrina revelou um clara zona livre transparente com concentração de 500µg/mL mostrando uma hidrólise de 24mm. O efeito trombolítico dos compostos de Streptomyces sp.VITJS4 também foi demonstrado no ensaio in vitro de lise dos coágulos em que a percentagem de trombólise pelo extrato bruto mostrou 90±1.7% a uma concentração de 1000µg/mL, enquanto que a percentagem de trombólise pela estreptoquinase foi de 100± 00%. Os compostos bioativos foram estudados posteriormente através da análise espectrofotométrica. O perfil ultra violeta visível (UV-VIS profile, em inglês) mostrou diferentes picos variando entre 400-700 nm com diferentes absorções respectivamente. Os dados confirmaram a presença de ambos os análogos com absorção máxima em 210 e 300 nm. Um método sensível usando a técnica LC-MS (Liquid chromatography­mass spectrometry) foi otimizado para a separação e identificação metabólitos bioativos que foram indicados pelas impressões digitais (?). Os resultados da análise LC-MS forneceram diferentes picos determinando a presença de compostos com diferentes atividades terapêuticas. O estudo atual refere-se ao composto bioativo como um agente trombolítico impressionante para futuros estudos em laboratório. Estudos futuros devem ser conduzidos para assegurar a eficácia e segurança de diferentes concentrações dos compostos bioativos para o desenvolvimento de drogas. Assim, os resultados reportados talvez sejam úteis para a descoberta de novas drogas trombolíticas de origem marinha.
Descritores: Streptomyces
Trombose
Técnicas In Vitro
Actinobacteria
Fibrinolíticos
Responsável: BR396.1 - Biblioteca Central


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Id: biblio-969229
Autor: Alves, Bruna Gomes; Martins, Cristian Marlon de Magalhães Rodrigues; Arcari, Marcos André; Peti, Ana Paula Ferranti; Moraes, Luiz Alberto Beraldo de; Santos, Marcos Veiga dos.
Título: Dose-response effect of crude extracts produced by actinobacteria on in vitro rumen fermentation / Padrão dose-resposta de extratos brutos produzidos por actinobactérias sobre a fermentação ruminal in vitro
Fonte: Braz. J. Vet. Res. Anim. Sci. (Online);55(3):e141243, Outubro 25, 2018. graf, tab.
Idioma: en.
Resumo: Actinobacteria have been researched as a source that produces crude extracts, which contain bioactive compounds able to act as antimicrobial agents. The present investigation evaluated the dose-response effect of two crude extracts, obtained at Caatinga rhizosphere (Caat) and Rhizophora mangle (AMC), on in vitro ruminal fermentation by:cumulative gas production, digestibility of dry (IVDMD) and organic matter (IVOMD), and short-chain fatty acids concentration (SCFA). Three multiparous Holstein dairy cows with ruminal fistula were used as the inoculum donors and fed a basal diet consisting of corn silage, soybean meal, urea, ground corn and mineral supplement. Ruminal fluid samples were incubated in glass bottles with 1 g of the dried and milled diet, a buffer solution, and the crude extracts evaluated in four doses (0.3, 0.6, 0.9 and 1.20 mg/10 mL inoculum) in a randomized block design, and the donators were considered as blocks with random effects. Additionally, negative controls were used. The results were expressed as average values based on triplicate analyses. Decreased cumulative gas production was observed according to linear dose response at 24, 48 and 72 h of incubation with the addition of Caat extract. The IVOMD showed a linear decrease at 72 h of incubation with dose Caat inclusion. Furthermore, the inclusion of Caat extract linearly reduced butyric and isovaleric acid concentrations, as well as acetate:propionate ratio. Finally, the Caat inclusion increased the propionic acid concentration in comparison to AMC extract. However, the inclusion of AMC extract did not affect any of the analyzed variables at the used doses. The Caat extract could be used as a modulator of in vitro ruminal fermentation, since it reduced acetate:propionate ratio and cumulative gas production.(AU)

As actinobactérias têm sido pesquisadas como fonte produtoras de extratos brutos que contêm compostos bioativos capazes de atuar como agentes antimicrobianos. O presente trabalho investigou o efeito dose-resposta de dois extratos brutos, AMC e Caat, na fermentação ruminal in vitro por: produção cumulativa de gás, digestibilidade in vitro da matéria seca (IVDMD) e matéria orgânica (IVOMD) e concentração de ácidos graxos de cadeia curta (SCFA). Três vacas leiteiras da raça Holandesa, multíparas e portadoras de fístula ruminal foram utilizadas como doadoras de inóculo ruminal e foram alimentadas com uma dieta basal composta por silagem de milho, farelo de soja, ureia, milho moído e suplemento mineral. As amostras de inóculo ruminal foram incubadas em garrafas de vidro com 1 g da dieta seca e moída, solução tampão e os extratos brutos avaliados em quatro doses (0,3, 0,6, 0,9 e 1,20 mg/10 mL de inóculo) em delineamento em blocos casualizados, sendo as doadoras consideradas os blocos como efeito aleatório. Além disso, foram utilizados controles negativos para a correção da produção de gás. Os resultados foram expressos como valores médios com base em análises triplicadas. A diminuição da produção cumulativa de gás foi observada de acordo com a dose em resposta linear às 24, 48 e 72 h de incubação com a adição de extrato de Caat. A IVOMD mostrou uma diminuição linear com 72 h de incubação com inclusão de Caat. Além disso, a inclusão do Caat reduziu linearmente as concentrações de ácido butírico e isovalérico, bem como a proporção de acetato/propionato. Diferentemente, a inclusão do extrato de AMC não afetou nenhuma das variáveis analisadas nas doses utilizadas. O extrato de Caat pode ser usado como um modulador da fermentação ruminal in vitro, uma vez que reduziu a proporção de acetato/propionato e a produção de gás acumulada. (AU)
Descritores: Actinobacteria/química
Fermentação
Ionóforos/síntese química
Responsável: BR68.1 - Biblioteca Virginie Buff D'Ápice


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Id: biblio-889208
Autor: Rachedi, Kounouz; Zermane, Ferial; Tir, Radja; Ayache, Fatima; Duran, Robert; Lauga, Béatrice; Karama, Solange; Simon, Maryse; Boulahrouf, Abderrahmane.
Título: Effect of sulfonylurea tribenuron methyl herbicide on soil Actinobacteria growth and characterization of resistant strains
Fonte: Braz. j. microbiol;49(1):79-86, Jan.-Mar. 2018. tab, graf.
Idioma: en.
Resumo: ABSTRACT Repeated application of pesticides disturbs microbial communities and cause dysfunctions on soil biological processes. Granstar® 75 DF is one of the most used sulfonylurea herbicides on cereal crops; it contains 75% of tribenuron-methyl. Assessing the changes on soil microbiota, particularly on the most abundant bacterial groups, will be a useful approach to determine the impact of Granstar® herbicide. For this purpose, we analyzed Actinobacteria, which are known for their diversity, abundance, and aptitude to resist to xenobiotic substances. Using a selective medium for Actinobacteria, 42 strains were isolated from both untreated and Granstar® treated soils. The number of isolates recovered from the treated agricultural soil was fewer than that isolated from the corresponding untreated soil, suggesting a negative effect of Granstar® herbicide on Actinobacteria community. Even so, the number of strains isolated from untreated and treated forest soil was quite similar. Among the isolates, resistant strains, tolerating high doses of Granstar® ranging from 0.3 to 0.6% (v/v), were obtained. The two most resistant strains (SRK12 and SRK17) were isolated from treated soils showing the importance of prior exposure to herbicides for bacterial adaptation. SRK12 and SRK17 strains showed different morphological features. The phylogenetic analysis, based on 16S rRNA gene sequencing, clustered the SRK12 strain with four Streptomyces type strains (S. vinaceusdrappus, S. mutabilis, S. ghanaensis and S. enissocaesilis), while SRK17 strain was closely related to Streptomyces africanus. Both strains were unable to grow on tribenuron methyl as unique source of carbon, despite its advanced dissipation. On the other hand, when glucose was added to tribenuron methyl, the bacterial development was evident with even an improvement of the tribenuron methyl degradation. In all cases, as tribenuron methyl disappeared, two compounds were detected with increased concentrations. These by-products appeared to be persistent and were not degraded either chemically or by the studied strains. Based on these observations, we suggested that bacterial activity on carbon substrates could be directly involved in the partial breakdown of tribenuron methyl, by generating the required acidity for the first step of the hydrolysis. Such a process would be interesting to consider in bioremediation of neutral and alkaline tribenuron methyl-polluted soils.
Descritores: Actinobacteria/efeitos dos fármacos
Actinobacteria/crescimento & desenvolvimento
Sulfonatos de Arila/farmacologia
-Actinobacteria/genética
Actinobacteria/metabolismo
Sulfonatos de Arila/metabolismo
Responsável: BR1.1 - BIREME


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Id: biblio-888654
Autor: Massunari, Loiane; Novais, Renata Zoccal; Oliveira, Márcio Teixeira; Valentim, Diego; Dezan Junior, Eloi; Duque, Cristiane.
Título: Antimicrobial Activity and Biocompatibility of the Psidium cattleianum Extracts for Endodontic Purposes
Fonte: Braz. dent. j;28(3):372-379, May-June 2017. tab, graf.
Idioma: en.
Resumo: Abstract Psidium cattleianum (PC) has been displaying inhibitory effect against a variety of microorganisms, but this effect has not yet been tested against endodontic pathogens. The aim of this study was to evaluate the antimicrobial activity and biocompatibility of the aqueous (PCAE) and hydroethanolic (PCHE) extracts from Psidium cattleianum (PC) leaves. Minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) were determined using the microdilution broth method in order to analyze the antimicrobial effect against Enterococcus faecalis, Pseudomonas aeruginosa, Actinomyces israelii and Candida albicans in planktonic conditions. Biofilm assays were conducted only with the extracts that were able to determine the MLC for microorganisms in planktonic conditions. Immediate and late tissue reactions against PC extracts were evaluated using edemogenic test and histological analysis of subcutaneous implants in Wistar rats. The results showed that the MIC and MLC values ranged between 0.25 and 4 mg/mL. The MLC obtained for PCHE inhibited 100% growth of all the tested strains, except for C. albicans. PCAE had the same effect for E. faecalis and P. aeruginosa. Both PC extracts were able to eliminate E. faecalis biofilms and only the PCHE eliminated P. aeruginosa biofilms. The positive controls inhibited the growth of all tested strains in MIC and MLC essays, but no CHX tested concentrations were able to eliminate A. israelii biofilm. PCAE caused a discrete increase in the edema over time, while PCHE caused a higher initial edema, which decreased progressively. Both PCAE and PCHE extracts were biocompatible, but PCHE showed better results with slight levels of inflammation at 28 days. In conclusion, PCHE was biocompatible and presented better antimicrobial effect against important pathogens associated with persistent endodontic infections

Resumo Psidium cattleianum (PC) tem apresentado atividade inibitória frente diversos microrganismos, entretanto esse efeito ainda não foi testado contra microrganismos de interesse endodôntico. O objetivo desse estudo foi avaliar a atividade antimicrobiana e a biocompatibilidade dos extratos aquoso (EAPC) e hidroetanólico (EHPC) das folhas de Psidium cattleianum. As concentrações inibitória mínima (CIM) e letal mínima (CLM) foram determinadas pelo método de microdiluição em caldo, com o objetivo de analisar o efeito antimicrobiano frente Enterococcus faecalis, Pseudomonas aeruginosa, Actinomyces israelii e Candida albicans em condições planctônicas. Os ensaios de biofilme foram realizados somente com os extratos em que se determinou a CLM frente os microrganismos em condições planctônicas. Respostas teciduais imediata e tardia frente aos extratos de Psidium cattleianum foram avaliadas por teste edemogênico e análise histológica de implantes subcutâneos em ratos Wistar. Os resultados mostraram que CIM e CLM variaram entre 0,25 e 4 mg/mL. As CLMs determinadas pelo EHPC inibiram 100% do crescimento de todas as cepas testadas, exceto Candida albicans. EAPC apresentou o mesmo efeito para E. faecalis e P. aeruginosa. Ambos os extratos de PC conseguiram eliminar o biofilme de E. faecalis, e somente o EHPC eliminou o biofilme de P. aeruginosa. Os controles positivos inibiram o crescimento de todos os microrganismos testados nos ensaios de CIM e CLM, mas nenhuma das concentrações de clorexidina testadas foi capaz de eliminar o biofilme de A. israelii. O EAPC provocou um discreto aumento de edema com o tempo, enquanto EHPC provocou um edema inicial severo, que diminuiu progressivamente. Ambos os extratos EAPC e EHPC foram biocompatíveis, entretanto, EHPC apresentou melhores resultados com baixos níveis de inflamação em 28 dias. Pode-se concluir que EHPC foi biocompatível e apresentou melhor efeito antimicrobiano frente importantes patógenos associados a infecções endodônticas persistentes.
Descritores: Anti-Infecciosos/farmacologia
Materiais Biocompatíveis
Extratos Vegetais/farmacologia
Psidium/química
Tratamento do Canal Radicular
-Actinobacteria/efeitos dos fármacos
Biofilmes
Candida albicans/efeitos dos fármacos
Enterococcus faecalis/efeitos dos fármacos
Testes de Sensibilidade Microbiana
Pseudomonas aeruginosa/efeitos dos fármacos
Ratos Wistar
Limites: Animais
Masculino
Responsável: BR1.1 - BIREME


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Id: biblio-877875
Autor: Zúñiga-Bahamon, Andrés(edt); Tobar, Fabián(edt); Duque, Juan-Fernando(edt); Moreno, Pedro(edt).
Título: Acinetobacter baumannii: Resistencia y Virulencia mediada por el Sistema de Secreción Bacteriano Tipo IV / Acinetobacter baumannii: Resistance and Virulence mediated through bacterial type IV secretion system
Fonte: Rev. estomat. salud;21(2):37-45, 20130000.
Idioma: es.
Resumo: Introducción: Los sistemas de secreción bacterianos tipo IV tienen una variedad de funciones biológicas como el intercambio de material genético con otras bacterias y la translocación de ADN virulento, con sus proteínas efectoras, dentro de las células del huésped. Acinetobacter baumannii es un patógeno que causa infecciones en humanos y registra porcentajes altos de multiresistencia a fármacos. Objetivo: Relacionar el conocimiento so- bre los sistemas de secreción tipo IV con los patrones de resistencia y virulencia de Acinetobacter baumannii. Materiales y Métodos: Se realizó una buscada en PMC (NCBI) utilizando un conjunto de palabras claves. Resultados: De 133 artículos se analiza - ron 14 para establecer la relación entre los sistemas de secreción microbiano y la resistencia y virulencia de A. baumannii . Conclusiones: Los sistemas de secreción bacterianos tipo IV presentes en A. bau - mannii son una pieza clave en el enten - dimiento de los patrones de virulencia y resistencia...(Au)

Introduction: Type IV Bacterial Secretion Systems (TFSS) have a variety of biolo- gical functions such as the exchange of genetic material with other bacteria and virulent translocation of DNA with its effector proteins into host cells. A. bauman - nii is a pathogen that causes infections in humans and exhibits high rates of multidrug resistance to drugs. Objective: To relate how type IV secretion systems is associated with patterns of resistance and virulence in A. baumannii. Materials and Methods: Exhaustive search in PMC (NCBI) using a set of keywords was performed. Results: The search yielded 133 articles. Fourteen articles were analysed to deter - mine the bacterial secretion system and the resistant and virulence of AA. baumannii. Conclusions: Systems of bacterial type IV secretion present in A. baumannii are crucial in understanding the patterns of virulence and resistance...(Au)
Descritores: Actinobacteria
Odontologia
Diagnóstico Bucal
Transferência Genética Horizontal
Microbiologia
Medicina Bucal
Patologia Bucal
Revisão
Virulência
Fatores de Virulência
-Acinetobacter baumannii
Farmacorresistência Bacteriana
Sistemas de Secreção Tipo IV
Limites: Seres Humanos
Tipo de Publ: Revisão
Responsável: CO624.9



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