Página 1 dos resultados de 8490 itens digitais encontrados em 0.032 segundos

Antimicrobial activity of phenolic compounds identified in wild mushrooms, SAR analysis and docking studies

Alves, Maria José; Ferreira, Isabel C.F.R.; Froufe, Hugo J.C.; Abreu, Rui M.V.; Martins, Anabela; Pintado, Manuela
Fonte: Wiley Publicador: Wiley
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.15%
Aim and Methods: Although the antimicrobial activity of extracts from several mushroom species have been reported, studies with the individual compounds present in that extracts are scarce. Herein, the antimicrobial activity of different phenolic compounds identified and quantified in mushroom species from all over the world was evaluated. Furthermore, a structure activity relationship (SAR) analysis and molecular docking studies were performed, in order to provide insights in the mechanism of action of potential antimicrobial drugs for resistant microorganisms. Results: 2,4-Dihydroxybenzoic and protocatechuic acids were the phenolic compounds with higher activity against the majority of Gram negative and Gram positive bacteria. Furthermore, phenolic compounds inhibited more MRSA than methicillin sensible Staphylococcus aureus. MRSA was inhibited by 2,4-dihydroxybenzoic, vanillic, syringic (MICs=0.5 mg/mL) and p-coumaric (MIC= 1 mg/mL) acids, while these compounds at the same concentrations had no inhibitory effects against methicillin sensible Staphylococcus aureus. Conclusions: The presence of carboxylic acid (COOH), two hydroxyl (OH) groups in para and ortho positions of the benzene ring, as also a methoxyl (OCH3) group in the meta position seems to be important for anti-MRSA activity. Significance and Impact of the Study: Phenolic compounds could be used as antimicrobial agents...

Biotransformation using Mucor rouxii for the production of oleanolic acid derivatives and their antimicrobial activity against oral pathogens

CAPEL, Clarissa S.; SOUZA, Ana C. D. de; CARVALHO, Tatiane C. de; SOUSA, Joao P. B. de; AMBROSIO, Sergio R.; MARTINS, Carlos H. G.; CUNHA, Wilson R.; GALAN, Rosario H.; FURTADO, Niege A. J. C.
Fonte: SPRINGER HEIDELBERG Publicador: SPRINGER HEIDELBERG
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.15%
The goal of this study is to produce oleanolic acid derivatives by biotransformation process using Mucor rouxii and evaluate their antimicrobial activity against oral pathogens. The microbial transformation was carried out in shake flasks at 30A degrees C for 216 h with shaking at 120 rpm. Three new derivatives, 7 beta-hydroxy-3-oxo-olean-12-en-28-oic acid, 7 beta,21 beta-dihydroxy-3-oxo-olean-12-en-28-oic acid, and 3 beta,7 beta,21 beta-trihydroxyolean-12-en-28-oic acid, and one know compound, 21 beta-hydroxy-3-oxo-olean-12-en-28-oic acid, were isolated, and the structures were elucidated on the basis of spectroscopic analyses. The antimicrobial activity of the substrate and its transformed products was evaluated against five oral pathogens. Among these compounds, the derivative 21 beta-hydroxy-3-oxo-olean-12-en-28-oic acid displayed the strongest activity against Porphyromonas gingivalis, which is a primary etiological agent of periodontal disease. In an attempt to improve the antimicrobial activity of the derivative 21 beta-hydroxy-3-oxo-olean-12-en-28-oic acid, its sodium salt was prepared, and the minimum inhibitory concentration against P. gingivalis was reduced by one-half. The biotransformation process using M. rouxii has potential to be applied to the production of oleanolic acid derivatives. Research and antimicrobial activity evaluation of new oleanolic acid derivatives may provide an important contribution to the discovery of new adjunct agents for treatment of dental diseases such as dental caries...

Cassava starch composite films incorporated with cinnamon essential oil: Antimicrobial activity, microstructure, mechanical and barrier properties

Souza, A. C.; Goto, G. E. O.; Mainardi, J. A.; Coelho, Antonio Carlos Vieira; Tadini, Carmen Cecilia
Fonte: Biblioteca Digital da Produção Intelectual da USP Publicador: Biblioteca Digital da Produção Intelectual da USP
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.15%
Antimicrobial activity of cinnamon and clove essential oils is widely known; however their application to polymeric materials is already limited. Based on results of their minimum inhibitory concentration against Penicillium commune and Eurotium amstelodami, cinnamon was chosen to be incorporated into cassava starch films in order to develop an active packaging. The effect of cinnamon essential oil were evaluated on antimicrobial activity, mechanical and barrier properties of films and the results were compared with those of control films (without antimicrobial agent). ANOVA (P < 0.05) showed that the essential oil content influenced significantly the properties of the films. The release of antimicrobial agent and the microstructure of cassava films incorporated with cinnamon essential oil were also studied. Furthermore, all films, containing different amounts of essential oil, showed effective antimicrobial activity against P. commune and E. amstelodami, fungi commonly found in bread products.; FAPESP; CAPES

Síntese e determinação da atividade antimicrobiana de 2-[5-nitro-tiofen-2-il]-3-acetil-5-[4-fenil-substituído]-2,3-diidro-1,3,4-oxadiazol frente à cepa ATCC 25923 de Staphylococcus aureus; Synthesis and determination of antimicrobial activity of 2-[5-nitro-thiophen-2-yl]-3-acetyl-5-[4-substitued-phenyl]-3,4-dihydro-1,3,4-oxadiazolines against ATCC 25923 Staphylococcus aureus strain

Almeida, Leonardo Viana de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 12/02/2009 PT
Relevância na Pesquisa
66.22%
A introdução de um grupo substituinte na molécula de um fármaco promove alterações químico-estruturais que, por sua vez, modificam suas propriedades físicoquímicas. O arranjo espacial de átomos ou grupos de átomos, em especial grupos funcionais, na molécula de um fármaco, expressos por meio de suas propriedades físico-químicas, influenciam direta ou indiretamente na interação fármaco-receptor. Esta, por sua vez, determina aspectos farmacológicos e farmacocinéticos que influem na eficácia terapêutica do medicamento. Assim, uma série de compostos 2-[5-nitro-tiofen-2-il]-3-acetil-5-[4-fenil-substituído]-2,3-diidro-1,3,4-oxadiazolínicos foi planejada e os análogos foram sintetizados, identificados estruturalmente e avaliados in vitro quanto a atividade antimicrobiana frente a Staphylococcus aureus (cepa ATCC 25923), expressa pela determinação da concentração inibitória mínima. Cepas desta bactéria são comuns em infecções hospitalares e frequentemente apresentam caráter de multi-resistência, portanto, alternativas aos fármacos comumente empregados na terapia antibacteriana, especialmente em infecções multi-resitentes, são alvo de estudos e desenvolvimento. Relações entre mudanças estruturais de 2-[5-nitro-tiofen-2-il]-3-acetil-5-[4- fenil-substituído]-2...

Estudo da biocompatibilidade do cimento de aluminato de cálcio para uso odontológico, avaliação do pH, liberação de íons cálcio e atividade antimicrobiana; Biocompatibility of calcium aluminate cement for dental use, evaluation of pH, calcium ion release and antimicrobial activity

Aguilar, Fabiano Gamero
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 20/04/2012 PT
Relevância na Pesquisa
66.14%
O objetivo desse estudo foi avaliar o pH, a liberação de íons cálcio, a atividade antimicrobiana in vitro de cimento de aluminato de cálcio (EndoBinder) com diferentes radiopacificadores (óxido de bismuto, óxido de zinco e óxido de zircônia) e a biocompatibilidade do cimento acrescido de óxido de bismuto como agente radiopacificador, em comparação ao mineral trióxido agregado (MTA). Para a avaliação do pH e a liberação de íons cálcio, 25 amostras (n=5) de 2,0 x 10 mm foram obtidas de EndoBinder Puro (EBP), EndoBinder com Óxido de Bismuto (EBOB), EndoBinder com Óxido de Zinco (EBOZn), EndoBinder com Óxido de Zircônia (EBOZr) e Mineral Trióxido Agregado (MTA), que foram imersas em 10 ml água destilada e deionizada (pH=6,9). Após 2, 4, 12, 24, 48 horas, 7, 14 e 28 dias, foi medido o pH e a quantidade de íons cálcio da água onde as amostras foram imersas. Para a determinação in vitro da atividade antimicrobiana dos cimentos (EBP, EBOB, EBOZN, EBOZr e MTA), foram obtidas 15 amostras de cada material (n=3) de 5,0 x 5,0 mm colocadas em contato com 5 tipos de microrganismos: Escherichia coli (ATCC 25922), Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 25923), Candida albicans (ATCC 10231) e a Candida glabrata (ATCC 2001) em placas de petri com Agar (Muller Hinton e Sabouraud Dextrose) deixadas em temperatura ambiente por 2 horas para a pré-difusão e depois incubadas a 37°C por 24 horas. Utilizou-se uma régua milimetrada com precisão de 0...

Atividade Antimicrobiana dos Meis Produzidos por Apis mellifera e Abelhas sem Ferrão Nativas do Brasil; Antimicrobial Activity of Honey Produced by Apis mellifera and Native Brazilian Stingless Bees

Bazoni, Matheus de Oliveira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 14/08/2012 PT
Relevância na Pesquisa
66.21%
Nós avaliamos a atividade antimicrobiana do mel coletado de ninhos de 12 espécies de abelhas nativas sem ferrão comumente encontrados no Brasil e 25 amostras de mel de Apis mellifera não pasteurizados que foram identificadas como sendo unifloral e uma amostra de mel multifloral. A atividade antimicrobiana de cada amostra de mel foi testada contra cinco espécies de bactérias patogênicas, uma espécie de fungo patogênico e uma espécie de levedura patogênica, comparando esta atividade com o mel terapêutico de manuka produzido por abelhas Apis mellifera na Nova Zelândia a partir do néctar de Leptospermum scoparium (Myrtaceae). Cinco das treze amostras de mel das abelhas sem ferrão foram bactericidas e oito foram fungicidas contra o fungo patogênico Trichophyton rubrum. Somente a levedura Candida albicans foi resistente a todas as amostras de mel. As amostras de mel de Apis mellifera que apresentaram atividade bactericida foram caju, romã e cana, nenhuma das amostras de mel de A. mellifera afetou o fungo T. rubrum. Os meis de Nannotrigona testaceicornis, Plebeia remota, Tetragona clavipes e Scaptotrigona depilis todos com alto nível de atividade antimicrobiana, foram significativamente mais eficiente em termos de atividade antimicrobiana que o mel de manuka...

Screening for antimicrobial activity among bacteria isolated from the amazon basin

Motta, Amanda de Souza da; Olivera, Florencia Cladera; Brandelli, Adriano
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
Relevância na Pesquisa
66.21%
Bacteria producing antimicrobial activity were identified among 86 isolates from aquatic environments of Brazilian Amazon Basin. Antimicrobial activity against at least one indicator strain was detected for 59 isolates (68.6%). Inhibitory activity was mostly against Gram-positive bacteria, such as Listeria monocytogenes and Bacillus cereus. The antimicrobial substances produced by 19 strains that showed higher inhibitory activity were partially characterized. These antimicrobial substances showed thermal resistance for up to 100°C and partial resistance to proteolytic treatment. Some antimicrobials were partially resistant to pronase E at 2 mg ml-1 or to treatment with trichloroacetic acid. Detection of antimicrobial activity on polyacrylamide gels revealed that the molecular weight of the compounds was lower than 14 kDa. Several strains showed antibacterial activity, which in some cases appear to be related to antimicrobial peptides. The potential of these microorganisms to produce useful antimicrobial compounds is great and must be better explored.

Dimerization of aurein 1.2: Effects in structure, antimicrobial activity and aggregation of Cândida albicans cells

Lorenzón, E. N.; Sanches, P. R S; Nogueira, L. G.; Bauab, T. M.; Cilli, Eduardo Maffud
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 1521-1528
ENG
Relevância na Pesquisa
66.14%
Antimicrobial peptides (AMPs) are a promising solution to face the antibiotic-resistant problem because they display little or no resistance effects. Dimeric analogues of select AMPs have shown pharmacotechnical advantages, making these molecules promising candidates for the development of novel antibiotic agents. Here, we evaluate the effects of dimerization on the structure and biological activity of the AMP aurein 1.2 (AU). AU and the C- and N-terminal dimers, (AU)2K and E(AU)2, respectively, were synthesized by solid-phase peptide synthesis. Circular dichroism spectra indicated that E(AU)2 has a coiled coil structure in water while (AU)2K has an α-helix structure. In contrast, AU displayed typical spectra for disordered structures. In LPC micelles, all peptides acquired a high amount of α-helix structure. Hemolytic and vesicle permeabilization assays showed that AU has a concentration dependence activity, while this effect was less pronounced for dimeric versions, suggesting that dimerization may change the mechanism of action of AU. Notably, the antimicrobial activity against bacteria and yeast decreased with dimerization. However, dimeric peptides promoted the aggregation of C. albicans. The ability to aggregate yeast cells makes dimeric versions of AU attractive candidates to inhibit the adhesion of C. albicans to biological targets and medical devices...

Chemical Characterization and Antimicrobial Activity Evaluation of Natural Oil Nanostructured Emulsions

Alencar, Everton N.; Xavier-Junior, Francisco H.; Morais, Andreza R. V.; Dantas, Teresa R. F.; Dantas-Santos, Nednaldo; Verissimo, Lourena M.; Rehder, Vera L. G.; Chaves, Guilherme M.; Oliveira, Anselmo G.; Egito, E. Socrates T.
Fonte: Amer Scientific Publishers Publicador: Amer Scientific Publishers
Tipo: Artigo de Revista Científica Formato: 880-888
ENG
Relevância na Pesquisa
66.17%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); The aim of this work was to investigate the antimicrobial activity of nanostructured emulsions based on copaiba (Copaifera langsdotffii) resin-oil, copaiba essential oil, and bullfrog (Rana catesbeiana Shaw) oil against fungi and bacteria related to skin diseases. Firstly, the essential oil was extracted from copaiba resin-oil and these oils, along with bullfrog oil, were characterized by gas chromatography combined with mass spectrometry (GC-MS). Secondly, nanostructured emulsion systems were produced and characterized. The antimicrobial susceptibility assay was performed, followed by the Minimum Inhibitory Concentration (MIC) determination, the bioautography assay, and the antibiofilm determination. Strains of the genera Staphylococcus, Pseudomonas, and Candida were used. The CG-MS analysis was able to identify the components of copaiba resin-oil, copaiba essential oil, and bullfrog oil. The MIC assay in association with the bioautography revealed that some esters of palmitic and oleic acids, alpha-curcumene, alpha-himachalene, isothujol, and alpha-fenchene-probably inhibited some strains. The nanostructured emulsions based on copaiba resin-oil and essential oil improved the antimicrobial activity of the pure oils...

Gallic acid and cyclodextrins : inclusion complexes and antimicrobial activity

Pinho, Eva Patrícia Paiva Santos; Soares, Graça M. B.; Henriques, Mariana
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2013 ENG
Relevância na Pesquisa
66.19%
Gallic acid (GA), or 3,4,5-trihydroxybenzoic acid, is the commonest and simplest phenolic acid, with just one aromatic ring. This phenolic molecule has been described as antioxidant, anti-inflammatory and anti-tumour, also, antimicrobial and anti-fungal activity has been attributed to it. Besides all the GA biological activities, this compound is cheap, due to the easy plant extraction, and non-toxic. Thus, this phenolic acid has been widely used in food, drugs and cosmetic industry. GA, as other phenolic compounds, is susceptible to environmental factors which may lead to the losing their structural integrity and bioactivity. This can be overcome by the encapsulation with cyclodextrins (CD). They are cyclic oligosaccharides arising from the degradation of starch; inexpensive and friendly to humans. CD are able to form an inclusion complex with a wide range of bioactive molecules, including hydrophobic ones, protect and modulate their release. In the present work, the formation of an inclusion complex (IC) between βCD, HPβCD (2-Hydroxypropyl-β-cyclodextrin) or MβCD (methyl-β-cyclodextrin) and GA was analysed by UV spectrophotometry. The antimicrobial activity of the complexes was also assessed, by qualitative and quantitative methods. The influence of the buffer and pH on the formation of the IC and on the GA antimicrobial activity was also tested. The IC formation was analysed in 2 buffer solutions (K2HPO4/ KH2PO4 and H3PO4/NaOH). The GA and IC absorbance spectrum showed different appearances depending on the buffer used. When K2HPO4/ KH2PO4 was used...

Antimicrobial activity of the essential oil from Lippia sidoides, carvacrol and thymol against oral pathogens

Botelho,M.A.; Nogueira,N.A.P.; Bastos,G.M.; Fonseca,S.G.C.; Lemos,T.L.G.; Matos,F.J.A.; Montenegro,D.; Heukelbach,J.; Rao,V.S.; Brito,G.A.C.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2007 EN
Relevância na Pesquisa
66.15%
Dental caries and periodontal disease are associated with oral pathogens. Several plant derivatives have been evaluated with respect to their antimicrobial effects against such pathogenic microorganisms. Lippia sidoides Cham (Verbenaceae), popularly known as "Alecrim-pimenta" is a typical shrub commonly found in the Northeast of Brazil. Many plant species belonging to the genus Lippia yield very fragrant essential oils of potential economic value which are used by the industry for the commercial production of perfumes, creams, lotions, and deodorants. Since the leaves of L. sidoides are also extensively used in popular medicine for the treatment of skin wounds and cuts, the objective of the present study was to evaluate the composition and antimicrobial activity of L. sidoides essential oil. The essential oil was obtained by hydro-distillation and analyzed by GC-MS. Twelve compounds were characterized, having as major constituents thymol (56.7%) and carvacrol (16.7%). The antimicrobial activity of the oil and the major components was tested against cariogenic bacterial species of the genus Streptococcus as well as Candida albicans using the broth dilution and disk diffusion assays. The essential oil and its major components thymol and carvacrol exhibited potent antimicrobial activity against the organisms tested with minimum inhibitory concentrations ranging from 0.625 to 10.0 mg/mL. The most sensitive microorganisms were C. albicans and Streptococcus mutans. The essential oil of L. sidoides and its major components exert promising antimicrobial effects against oral pathogens and suggest its likely usefulness to combat oral microbial growth.

Interference of heating on the antimicrobial activity and chemical composition of Origanum vulgare L. (Lamiaceae) essential oil

Souza,Evandro Leite de; Stamford,Tânia Lúcia Montenegro; Lima,Edeltrudes de Oliveira; Barbosa Filho,José Maria; Marques,Márcia Ortiz Mayo
Fonte: Sociedade Brasileira de Ciência e Tecnologia de Alimentos Publicador: Sociedade Brasileira de Ciência e Tecnologia de Alimentos
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2008 EN
Relevância na Pesquisa
66.2%
Origanum vulgare L. (oregano), Lamiaceae, essential oil has a variety of biological properties and its antimicrobial activity has received a renewed interest for use in food conservation. The aim of this study was to evaluate the interference of heating on the antimicrobial activity and chemical composition of O. vulgare essential oil. The antimicrobial activity of the essential oil kept at room temperature and exposed to different heating temperatures (60, 80, 100 and 120 °C during 1 hour) was evaluated by observing antimicrobial effectiveness at absolute concentration and determining MIC values by the solid medium diffusion procedure. The essential oil chemical composition analysis was performed by GC-MS. O. vulgare essential oil showed interesting antimicrobial activity on all assayed microbial strains (Candida albicans, C.krusei, C. tropicalis, Bacillus cereus, Escherichia coli, Staphylococcus aureus, Yersinia enterocolitica, Salmonella enterica, Serratia marcencens), noted by large growth inhibition zones (30-42 mm). Heating treatment showed no significant interference (p < 0.05) on the essential oil antimicrobial activity, noted by the development of microbial growth inhibition zones with similar or close diameters when evaluating the essential oil kept at room temperature and after exposure to different thermal treatments. MIC values oscillated between 10and 40 µL.mL-1 (20µL.mL-1 for most strains). However...

Preliminary study of the antimicrobial activity of Mentha x villosa Hudson essential oil, rotundifolone and its analogues

Arruda,Thúlio. A.; Antunes,Rossana M.P.; Catão,Raissa M.R.; Lima,Edeltrudes O.; Sousa,Damião P.; Nunes,Xirley P.; Pereira,Maria S.V.; Barbosa-Filho,José M.; Cunha,Emidio V. L. da
Fonte: Sociedade Brasileira de Farmacognosia Publicador: Sociedade Brasileira de Farmacognosia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2006 EN
Relevância na Pesquisa
66.16%
Essential oils present antimicrobial activity against a variety of bacteria and yeasts, including species resistant to antibiotics and antifungicals. In this context, this work aims at the evaluation of the antimicrobial activity of the essential oil of Mentha x villosa Hudson ("hortelã da folha miúda"), its major component (rotundifolone) and four similar analogues of rotundifolone (limonene oxide, pulegone oxide, carvone epoxide and (+)-pulegone) against strain standards of Staphylococcus aureus ATCC 25923, E. coli ATCC 25922, Pseudomona aeruginosa ATCC 27853, Candida albicans ATCC 76645 and one strain of meticilin - resistant Staphylococcus aureus - MRSA (171c) from human clinic. The method of the diffusion in plates with solid medium was used. The results showed that the oil of Mentha x villosa, rotundifolone, limonene oxide and (+)-pulegone, are similar regarding the antimicrobial activity against the tested strains of S. aureus and C. albicans. All of the products present antimocrobial potential with antibacterial activity for S. aureus ATCC 25923 and antifungal activity for C. albicans ATCC 76645. None of the products presented antimicrobial activity for the strains of E. coli ATCC 25922 and P. aeruginosa ATCC 27853, representatives of the Gram negative bacteria.

In vitro evaluation of the antimicrobial activity of five root canal sealers

Gomes,Brenda Paula Figueiredo de Almeida; Pedroso,José Assis; Jacinto,Rogério Castilho; Vianna,Morgana Eli; Ferraz,Caio Cezar Randi; Zaia,Alexandre Augusto; Souza-Filho,Francisco José de
Fonte: Fundação Odontológica de Ribeirão Preto Publicador: Fundação Odontológica de Ribeirão Preto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2004 EN
Relevância na Pesquisa
66.15%
The aim of the present study was to analyze the antimicrobial properties of five endodontic sealers: Endo Fill, Endomethasone, Endomethasone N, Sealer 26 and AH-Plus, against the following microorganisms: Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Streptococcus sanguis and Actinomyces naeslundii. The sealers were tested immediately, 24 h, 48 h and 7 days after manipulation.The direct contact method through the observation of the microbial growth in liquid medium and the agar diffusion test were used to evaluate the antimicrobial properties of the sealers. The results, in both methodologies used, showed that immediately after manipulation, Endo-Fill and Endomethasone demonstrated the highest antimicrobial activity, with no statistically significant difference between them. Sealer 26 demonstrated the lowest antimicrobial activity. At all other times after manipulation, there were no statistically significant differences among all the sealers tested. In conclusion, none of the sealers totally inhibited the growth of the microorganisms. Furthermore, the antimicrobial activity of each sealer decreased with time and was dependent upon the microbial susceptibility to them.

Screening for antimicrobial activity among bacteria isolated from the Amazon Basin

Motta,Amanda S.; Cladera-Olivera,Florencia; Brandelli,Adriano
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2004 EN
Relevância na Pesquisa
66.21%
Bacteria producing antimicrobial activity were identified among 86 isolates from aquatic environments of Brazilian Amazon Basin. Antimicrobial activity against at least one indicator strain was detected for 59 isolates (68.6%). Inhibitory activity was mostly against Gram-positive bacteria, such as Listeria monocytogenes and Bacillus cereus. The antimicrobial substances produced by 19 strains that showed higher inhibitory activity were partially characterized. These antimicrobial substances showed thermal resistance for up to 100°C and partial resistance to proteolytic treatment. Some antimicrobials were partially resistant to pronase E at 2 mg ml-1 or to treatment with trichloroacetic acid. Detection of antimicrobial activity on polyacrylamide gels revealed that the molecular weight of the compounds was lower than 14 kDa. Several strains showed antibacterial activity, which in some cases appear to be related to antimicrobial peptides. The potential of these microorganisms to produce useful antimicrobial compounds is great and must be better explored.

Antimicrobial activity and bioautographic study of antistaphylococcal components from Caesalpinia pyramidalis Tull.

Saraiva,Antonio Marcos; Saraiva,Cristiane Lopes; Gonçalves,Admário Marques; Soares,Rogério Ribeiro; Mendes,Fabrício de Oliveira; Cordeiro,Risonildo Pereira; Xavier,Haroudo Satiro; Pisciottano,Maria Nelly Caetano
Fonte: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2012 EN
Relevância na Pesquisa
66.16%
The antimicrobial activity of dry methanol and ethyl acetate extracts for the leaves, bark of the stem, peel of the root, flower, fruit and seed of Caesalpinia pyramidalis Tull. (catingueira) was performed against seventeen isolates of Staphylococcus aureus MRSA multiresistant strains, which included two isolates of S. aureus MSSA and two ATCC strains. The antimicrobial activity was tested by the agar diffusion method and the Minimum Inhibitory Concentration (MIC) was determined. The dry methanol extract of the root showed good antimicrobial activity with a MIC of less than 0.5 mg.mL-1. The dry ethyl acetate extracts exhibited lower antimicrobial activity, which might be explained by solubility problems and less diffusion in the agar medium. Results of the bioautographies also confirmed inhibition halos corresponding to the active substances present in the leaves, as well as in the flower of C. pyramidalis. The phytochemical study of the leaves, bark of the stem, peel of the root, flower and fruit of extracts from C. pyramidalis confirmed the presence of a number of known antimicrobial agents including ursolic acid, quercetin, catechin, ellagic acid, sitosterol, flavonoids, proanthocyanidins and gallic acid.

Atividade antimicrobiana de microrganismos presentes nos gr??os de kefir; Antimicrobial activity of microorganisms present in kefir grains

DIAS, Priscila Alves
Fonte: Universidade Federal de Pelotas; Veterin??ria; Programa de P??s-Gradua????o em Veterin??ria; UFPel; BR Publicador: Universidade Federal de Pelotas; Veterin??ria; Programa de P??s-Gradua????o em Veterin??ria; UFPel; BR
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
66.19%
Kefir is fermented milk, acid, slightly alcoholic, home made from grains that contain a relatively stable population of symbiotic microorganisms, embedded in a matrix composed of polysaccharides and proteins. Servings of milk added kefir grains were experimentally contaminated with Escherichia coli O157:H7, Salmonella enterica subsp. enterica serotypes Typhimurium and Enteritidis, Staphylococcus aureus and Listeria monocytogenes. Samples were analyzed for the presence of microorganisms after 0, 6, 12, 24, 48 and 72 hours of fermentation. Sixty bacterial strains isolated from kefir grains were tested for antimicrobial activity against the same pathogens. From grains were sown by spreading in MRS agar to obtain isolated colonies. The antimicrobial activity was studied through the test of antagonism. The antimicrobial activity of supernatants of lactic acid bacteria that were active in the test of antagonism was tested. The experiment was repeated using supernatants neutralized with pH. Salmonella Typhimurium and Enteritidis survived for 24 hours in the kefir fermentation. E. coli O157:H7, S. aureus and L. monocytogenes were recovered by 72 after the start of fermentation. All isolates showed antimicrobial activity against at least one of the pathogens used in the test of antagonism. Supernatants of 25 isolates showed inhibitory activity. However...

Messung antimikrobieller Aktivität als Marker für chronisch entzündliche Darmerkrankungen; Measurement of antimicrobial activity as a marker for chronic inflammatory bowel diseases

Adam, Nathalie
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
Relevância na Pesquisa
66.2%
In der vorliegenden Arbeit wurden zwei getrennte, unterschiedliche Assay-Methoden (Radialdiffusionsassay und durchflusszytometrischer Assay (FACS-Assay)) zum Nachweis der antimikrobiellen Aktivität gegen den Bakterienstamm E. coli K12 in Stuhlproben von Morbus Crohn- und Colitis ulcerosa-Patienten im Vergleich zu Kontrollpersonen verwendet. Im ersten Teil der Arbeit wurden die Ergebnisse des Radialdiffusionsassays dargestellt. Im zweiten Teil wurde zur Sicherung der Ergebnisse ein durchflusszytometrischer Assay durchgeführt und beide Ergebnisse miteinander verglichen. Des Weiteren wurde durch fäkales Calprotectin die Krankheitsaktivität bei Morbus Crohn- und Colitis ulcerosa-Patienten im Vergleich zu gesunden Kontrollpersonen nachgewiesen. In dieser Dissertation konnte gezeigt werden, dass: 1. Die antimikrobielle Aktivität gegen den Bakterienstamm E. coli K12 lässt sich auch in den Stuhlproben nachweisen. 2. Die Ergebnisse zeigen eine gute Übereinstimmung und Ergänzung von RDA und FACS-Assay bei der Darstellung antimikrobieller Aktivität gegen E. coli K12 in Stuhlproben bei Patienten mit Morbus Crohn, Colitis ulcerosa und Kontrollpersonen. 3. Die Stuhlprobenextrakte von Morbus Crohn-Patienten weisen eine deutlich signifikante Verminderung der antimikrobiellen Aktivität gegen E. coli K12 nach. Obwohl...

Screening antimicrobial activity of various extracts of Urtica dioica

Modarresi-Chahardehi,Amir; Ibrahim,Darah; Fariza-Sulaiman,Shaida; Mousavi,Leila
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2012 EN
Relevância na Pesquisa
66.18%
Urtica dioica or stinging nettle is traditionally used as an herbal medicine in Western Asia. The current study represents the investigation of antimicrobial activity of U. dioica from nine crude extracts that were prepared using different organic solvents, obtained from two extraction methods: the Soxhlet extractor (Method I), which included the use of four solvents with ethyl acetate and hexane, or the sequential partitions (Method II) with a five solvent system (butanol). The antibacterial and antifungal activities of crude extracts were tested against 28 bacteria, three yeast strains and seven fungal isolates by the disc diffusion and broth dilution methods. Amoxicillin was used as positive control for bacteria strains, vancomycin for Streptococcus sp., miconazole nitrate (30µg/mL) as positive control for fungi and yeast, and pure methanol (v/v) as negative control. The disc diffusion assay was used to determine the sensitivity of the samples, whilst the broth dilution method was used for the determination of the minimal inhibition concentration (MIC). The ethyl acetate and hexane extract from extraction method I (EA I and HE I) exhibited highest inhibition against some pathogenic bacteria such as Bacillus cereus, MRSA and Vibrio parahaemolyticus. A selection of extracts that showed some activity was further tested for the MIC and minimal bactericidal concentrations (MBC). MIC values of Bacillus subtilis and Methicillin-resistant Staphylococcus aureus (MRSA) using butanol extract of extraction method II (BE II) were 8.33 and 16.33mg/mL...

Antimicrobial activity of two brazilian commercial propolis extracts;

Rezende, Giovanna Pires da Silva Ribeiro; Pimenta, Fabiana Cristina; Costa, Luciane Ribeiro de Rezende Sucasas
Fonte: UNICAMP/FOP Publicador: UNICAMP/FOP
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ;
Publicado em 25/11/2015 EN
Relevância na Pesquisa
66.17%
The antimicrobial activity of propolis extracts is well documented, but little is known about the antimicrobial properties of commercial products containing propolis, since these vary according to the geographical region in which the propolis is obtained. This study evaluated the antimicrobial activity of two samples of commercial propolis on 26 species of microorganisms obtained from ATCC and some wild strains: Gram-positive cocci and bacilli, and Gram-negative rods and yeasts. The tested products were two samples of Brazilian commercial propolis from Apis Flora™: 11.0% ethanolic extract of propolis (EEP) and Propomax™ 11.0% extract of propolis without alcohol (EP). Antimicrobial activity was determined by the agar diffusion technique, well method. MIC was determined for Staphylococcus sp. and Streptococcus mutans using the method of broth dilution with the propolis extract in serial concentrations. EEP and EP showed antimicrobial activity against all tested bacteria and yeasts, having a more pronounced action against Gram-positive bacteria and Candida albicans ATCC 10231, and a less evident activity against Gram-negative and Candida albicans FT2010. For S. mutans, the EEP MIC ranged from 8.8 to 4.4 mL of propolis, and the EP MIC...