Base de dados : LILACS
Pesquisa : B03.660.250 [Categoria DeCS]
Referências encontradas : 5 [refinar]
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Id: lil-748236
Autor: Pawar, Ravindra; Mohandass, Chellandi; Sivaperumal, Elakkiya; Sabu, Elaine; Rajasabapathy, Raju; Jagtap, Tanaji.
Título: Epiphytic marine pigmented bacteria: A prospective source of natural antioxidants
Fonte: Braz. j. microbiol;46(1):29-39, 05/2015. tab, graf.
Idioma: en.
Resumo: Awareness on antioxidants and its significance in human healthcare has increased many folds in recent time. Increased demand requisite on welcoming newer and alternative resources for natural antioxidants. Seaweed associated pigmented bacteria screened for its antioxidant potentials reveals 55.5% of the organisms were able to synthesize antioxidant compounds. DPPH assay showed 20% of the organisms to reach a antioxidant zone of 1 cm and 8.3% of the strains more than 3 cm. Pseudomonas koreensis (JX915782) a Sargassum associated yellowish brown pigmented bacteria have better activity than known commercial antioxidant butylated hydroxytoluene (BHT) against DPPH scavenging. Serratia rubidaea (JX915783), an associate of Ulva sp. and Pseudomonas argentinensis (JX915781) an epiphyte of Chaetomorpha media, were also contributed significantly towards ABTS (7.2% ± 0.03 to 15.2 ± 0.09%; 1.8% ± 0.01 to 15.7 ± 0.22%) and FRAP (1.81 ± 0.01 to 9.35 ± 0.98; 7.97 ± 0.12 to 18.70 ± 1.84 μg/mL of AsA Eq.) respectively. 16S rRNA gene sequence analysis revealed bacteria that have higher antioxidant activity belongs to a bacterial class Gammaproteobacteria. Statistical analysis of phenolic contents in relation with other parameters like DPPH, ABTS, reducing power and FRAP are well correlated (p < 0.05). Results obtained from the current study inferred that the seaweed associated pigmented bacteria have enormous potential on antioxidant compounds and need to be extracted in a larger way for clinical applications.
Descritores: Antioxidantes/metabolismo
Organismos Aquáticos/classificação
Organismos Aquáticos/metabolismo
Gammaproteobacteria/classificação
Gammaproteobacteria/metabolismo
Alga Marinha/microbiologia
-Organismos Aquáticos/genética
Organismos Aquáticos/isolamento & purificação
DNA Bacteriano/química
DNA Bacteriano/genética
DNA Ribossômico/química
DNA Ribossômico/genética
Gammaproteobacteria/genética
Gammaproteobacteria/isolamento & purificação
Dados de Sequência Molecular
Pigmentos Biológicos/metabolismo
/genética
RNA, RIBOSOMAL, ABNORMALITIES, MULTIPLES/genética
Análise de Sequência de DNA
Responsável: BR1.1 - BIREME


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Id: lil-716093
Autor: Silva, Miriam Lopes da.
Título: Detecção e caracterização de elementos conjugativos integrativos em bactérias isoladas de amostras ambientais / Detection and characterization of integrative conjugative elements in bacteria isolated from environmental samples.
Fonte: São Paulo; s.n; 2014. 172 p. graf.
Idioma: pt.
Tese: Apresentada a Universidade de São Paulo. Faculdade de Saúde Pública. Departamento de Pratica de Saúde Pública para obtenção do grau de Doutor.
Resumo: O reconhecimento da resistência antimicrobiana como um fenômeno emergente em saúde pública, tem constituído um problema em nível mundial. O abuso na utilização de antibióticos na medicina humana e veterinária, e na agricultura, tem originado incremento na diversidade de micro-organismos resistentes, refletindo em falha terapêutica. Os mecanismos de resistência a antibióticos em micro-organismos são mediados principalmente por genes adquiridos de DNA exógeno. A dinâmica da transferência horizontal é realizada por meio de elementos genéticos móveis que carregam genes de resistência. A ampla distribuição deste tipo de estruturas, como o elemento SXT, isolado inicialmente em V. cholerae, tem contribuído para a disseminação de complexos específicos clonais em determinadas áreas geográficas. Este estudo pioneiro no Brasil pesquisou a presença de elementos SXT, em espécies bacterianas do grupo das gama proteobactérias em espécies ambientais, determinou suas características estruturais e funcionais, incluindo genes de resistência a antibióticos, bem como a sensibilidade aos antibióticos dentre os isolados bacterianos que os abrigam. O resultado foi a classificação de 43 elementos SXT obtidos no Brasil, através da comparação com aqueles descritos na literatura. Dentre os elementos SXT obtidos, quatro são albergados por Morganella morganii, fato inédito na literatura. O conhecimento da evolução bacteriana constitui importante ferramenta para estabelecer estratégias eficazes de controle e tratamento de infecções, sem aumentar a pressão seletiva sobre os micro-organismos, bem como instrumento preciso e de grande importância para subsidiar estudos epidemiológicos.

Recognition of antimicrobial resistance as an emerging phenomenon in public health has been a problem worldwide. The abuse in the use of antibiotics in human and veterinary medicine, and agriculture, has caused an increase in the diversity of resistant microorganisms, reflecting in treatment failure. The mechanisms of antibiotic resistance in microorganisms are primarily mediated by genes acquired from exogenous DNA. The dynamics of the horizontal transfer is performed by mobile genetic elements which carry resistance genes. The wide distribution of these structures, such as the SXT element originally isolated from V. cholerae, has contributed to the spread of specific clonal complexes in certain geographical areas. This pioneering study in Brazil researched the presence of SXT elements in the group of bacterial species in environmental gamma-proteobacteria species, determined their structural and functional characteristics, including genes for resistance to antibiotics and the antibiotic susceptibility among bacterial isolates that harbor them. The result was the classification of 43 SXT elements found in Brazil, by comparison with those found in the literature. Among the SXT elements found, four are sheltered by Morganella morganii, unprecedented in the literature. Knowledge of bacterial evolution is an important to establish effective strategies to control and treat infections without increasing the selective pressure on microorganisms, as well as a precise instrument and very important tool to support epidemiological studies.
Descritores: DNA Bacteriano
Meio Ambiente
Gammaproteobacteria
Genoma Bacteriano
Resistência Microbiana a Medicamentos/genética
Transferência Genética Horizontal/genética
-Adaptação Biológica
Componentes Genômicos
Biologia Molecular
Saúde Pública
Responsável: BR67.1 - CIR - Biblioteca - Centro de Informação e Referência
BR67.1; DR, 1165. CM. 55061/2014


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Id: lil-571372
Autor: Yang, Hongmei; Lou, Kai.
Título: Succession and growth strategy of a spring microbial community from kezhou sinter in China
Fonte: Braz. j. microbiol;42(1):41-45, Jan.-Mar. 2011. ilus.
Idioma: en.
Projeto: Open Project Program of the Specific Habitat Microorganisms Laboratory of Xinjiang; . 973 Pre-research Program of China.
Resumo: The succession and growth strategy of a spring microbial community under earthquake action were investigated. The majority of pre-earthquake isolates belonged to the Gammaproteobacteria, including two numerically dominant Stenotrophomonas sp. RB25 and Acinetobacter sp. RB11 (r-strategists). The predominant post-earthquake isolates were Alphaproteobacteria, with Rhizobium sp. RA42 (K-strategists) being dominant among these organisms.
Descritores: Crescimento Bacteriano
Biota
Terremotos
Microbiologia Ambiental
Infecções por Bactérias Gram-Negativas
Gammaproteobacteria/isolamento & purificação
Rhizobium/isolamento & purificação
Stenotrophomonas/isolamento & purificação
-Métodos
Estratégias
Técnicas
Tipo de Publ: Relatório Técnico
Responsável: BR32.1 - Serviço de Biblioteca e Informação Biomédica


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Id: lil-332488
Autor: Cubitto, M. A; Cabezalí, C. B.
Título: Tipificación y evaluación de la actividad degradadora de hidrocarburos de una cepa bacteriana aislada del estuario de Bahía Blanca, Argentina / Typing and evaluation of hydrocarbon-degrading activity of a bacterial strain isolated from the BahÝa Blanca estuary, Argentina
Fonte: Rev. argent. microbiol;33(3):141-148, jul.-sept. 2001.
Idioma: es.
Resumo: During screening for oil-degrading bacteria in sediments of BahÝa Blanca estuary, a bacterial strain was isolated which uses a limited number of organic compounds, especially lineal hydrocarbons. The goals of this study were to characterize the strain and to evaluate its activity on crude oil. Based on phenotypic characteristics and the analysis of 16S rDNA sequences, it was determined that the strain is strongly related to Alcanivorax borkumensis. The strain was cultured, under quasicontinuous conditions, with crude oil as sole source of carbon and energy. After 30 days of incubation, n-alkane decrease reached 86. The isoalkanes pristane and phitane were degraded more slowly, but a decrease of about 63 was obtained. The strain studied would be useful for the bioremediation of the local coasts, so that this study will be continued in order to obtain its successful application in the environment.
Descritores: Biodegradação Ambiental
Hidrocarbonetos
Gammaproteobacteria/isolamento & purificação
Microbiologia da Água
-Argentina
Cloreto de Sódio/análise
Gammaproteobacteria/classificação
Gammaproteobacteria/metabolismo
Gammaproteobacteria/ultraestrutura
Poluição Química da Água
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME


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Id: lil-309520
Autor: Leite, B; Ishida, M. L; Alves, E; Carrer, H; Pascholati, S. F; Kitajima, E. W.
Título: Genomics and X-ray microanalysis indicate that Ca2+ and thiols mediate the aggregation and adhesion of Xylella fastidiosa
Fonte: Braz. j. med. biol. res = Rev. bras. pesqui. méd. biol;35(6):645-650, June 2002. ilus.
Idioma: en.
Resumo: The availability of the genome sequence of the bacterial plant pathogen Xylella fastidiosa, the causal agent of citrus variegated chlorosis, is accelerating important investigations concerning its pathogenicity. Plant vessel occlusion is critical for symptom development. The objective of the present study was to search for information that would help to explain the adhesion of X. fastidiosa cells to the xylem. Scanning electron microscopy revealed that adhesion may occur without the fastidium gum, an exopolysaccharide produced by X. fastidiosa, and X-ray microanalysis demonstrated the presence of elemental sulfur both in cells grown in vitro and in cells found inside plant vessels, indicating that the sulfur signal is generated by the pathogen surface. Calcium and magnesium peaks were detected in association with sulfur in occluded vessels. We propose an explanation for the adhesion and aggregation process. Thiol groups, maintained by the enzyme peptide methionine sulfoxide reductase, could be active on the surface of the bacteria and appear to promote cell-cell aggregation by forming disulfide bonds with thiol groups on the surface of adjacent cells. The enzyme methionine sulfoxide reductase has been shown to be an auxiliary component in the adhesiveness of some human pathogens. The negative charge conferred by the ionized thiol group could of itself constitute a mechanism of adhesion by allowing the formation of divalent cation bridges between the negatively charged bacteria and predominantly negatively charged xylem walls
Descritores: Cálcio
Citrus
Gammaproteobacteria
Doenças das Plantas
Compostos de Sulfidrila
-Cálcio
Adesão Celular
Agregação Celular
Citrus
Microanálise por Sonda Eletrônica
Gammaproteobacteria
Genoma Bacteriano
Magnésio
Oxirredutases
Compostos de Sulfidrila
Enxofre
Responsável: BR1.1 - BIREME



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