886 resultados para pseudomonas aeruginosa


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Natural products have been studied aiming to understand their biological properties. Thus, this study aimed to investigate the antimicrobial activity of twenty-seven essential oils (EOs) used in aromatherapy procedures, a natural therapy with great emphasis currently used against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa strains. The agar dilution method was carried out and minimal inhibitory concentration against 50% and 90% of strains (MIC50% and MIC90% values) were reported. The S.aureus strains were highly susceptible with MIC90% from 0.21mg/mL to black pepper (Piper nigrum) and tea tree (Melaleuca alternifolia) to 26.52mg/mL with copaiba (Copaifera officinalis) EO. Cinnamon (Cinnamomum cassia) and clove (Syzygium aromaticum) EOs were effective against E.coli (2.0mg/mL) while the S.aromaticum EO was against P.aeruginosa (8.29mg/mL). Thus, the higher susceptibility of Gram-positive bacteria when compared with Gram-negative strains was found, and a large variability in the potential antibacterial has also been observed.

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A number of methods and products have been developed in order to eliminate or reduce the negative effects that hydrocarbons cause to the environment, including hydrophobic expanded vermiculite, used in oil residue filtering systems at gas stations. However, upon adsorbing organic compounds, the vermiculite is no longer used and is sent to landfills. The aim of the present study was to wash granular and powdered vermiculite containing oil lubricant in its pores with distilled water and solutions of 0.1% SDS surfactant and rhamnolipids, with the aim of removing the lubricant and the possibility of reusing the mineral. The greatest amount of lubricant removal was obtained through washing with 0.1% SDS and both granulometric forms. This may be associated to the industrial purification received by the surfactant. However, the biosurfactant is ecologically more viable due to its low toxicity and ease of degradability. In the readsorption tests, greatest adsorption was obtained with the granular vermiculite washed in SDS solution. In order to enable the reuse of the mineral, further tests are needed to enhance desorption/adsorption efficiency.

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The increase of the antimicrobial resistance and its propagation around the world are the biggest threats to the public health care and to the treatment of diseases caused by microorganisms. Nowadays the antimicrobial resistance has increased abruptly. The essential oils are volatile and aromatic compounds derived from parts of plants as flowers, leafs, fruits, seeds, roots, sprouts, among others. The activity of extracts and essential oils of several plant species have been recognized and studied by empirical methods since a long time, but its antimicrobial activities were confirmed recently. Medicinal plants are used in folk medicine as medicines, antibiotic, analgesic, sedative and anti-inflammatory. The use of medicinal plants like source of medicines is an alternative of therapeutics for diseases treatment. In Brazil, studies with this goal are very important, once medicinal plants have been used as a choice of treatment and prevention of infections and diseases in health areas. Considering the fact that some products from medicinal plants have antimicrobial properties it is expected that using screening programs, new potential medicaments could be developed. Otherwise, scientific researches focused on determining therapeutic potential of plants are limited, there are lack of scientific studies which confirms the potential antibiotics properties of a large number of plants. The aim of the present study is determinate the antimicrobial activity of 10 medicinal species belonging to CPMA - Collection of Medicinal and Aromatic Plants from CPQBA/UNICAMP. The minimal inhibitory (MIC) and minimal bactericidal or fungicidal concentration (MBC) will be determined against the bacteria Escherichia coli, Pseudomonas aeruginosa, Salmonella choleraesuis, Staphylococcus aureus and the yeast Candida albicans. Furthermore, will be conducted chemical identification and fractionation of essential oils and extract with better activity

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No Brasil, 90% de pacientes com insuficiência renal crônica ou aguda dependem dos procedimentos de hemodiálise para remover produtos de degradação metabólica, excesso de água e de sais minerais do organismo, a fim de restaurar o equilíbrio ácido-base e eletrolítico. Entretanto, o processo de osmose reversa, que visa remover todos os íons da água, também remove o cloro, que exerce efeito bacteriostático sob diversas bactérias autóctones, que passam a se multiplicar na água. Entre os principais grupos dessas bactérias, estão os bastonetes Gram negativos não fermentadores (BGN) e os mais frequentemente associados a bacteremias, em pacientes de hemodiálise são Pseudomonas aeruginosa, Stenotrophomonas maltophilia e Burkholderia cepacia. Essas bactérias podem produzir biofilmes, o que torna sua eliminação do encanamento quase impossível. Assim, o objetivo do trabalho foi a análise de água e do dialisato, da Unidade de Hemodiálise de um Hospital Universitário, na pesquisa dos três BGNs citados. Também foram utilizadas 42 cepas previamente isoladas do mesmo local. Entre as 67 amostras de água, foram isoladas 8 cepas de Pseudomonas aeruginosa e as 50 cepas foram submetidas à pesquisa do gene rpoS, um dos responsáveis pela produção de biofilme. Esse gene foi observado em 20 (40%) cepas, sendo 16 (80%) P. aeruginosa, seguida por 3 (15%) cepas de S. maltophilia e 1 (5%) de B. cepacia. Essas cepas foram submetidas à produção de biofilme a 35ºC (temperatura ótima de crescimento) e a 20ºC (temperatura média da água no encanamento da Unidade de Hemodiálise), em aço inoxidável (material de muitos instrumentos cirúrgicos), PVC (matéria prima da tubulação) e plástico de poliestireno (capacidade de produção de biofilmes em diferentes materiais). Em poliestireno, somente 1 (5%) cepa de P. aeruginosa produziu biofilme a 35ºC e a 20ºC, 2 (10%) cepas foram... (Resumo completo, clicar acesso eletrônico abaixo)

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O uso de plantas medicinais especialmente na América do Sul contribui significativamente para os cuidados básicos com a saúde. Para o tratamento de infecções comuns, muitas plantas são utilizadas no Brasil na forma de extrato bruto, infusões ou emplastros, sem nenhuma evidência científica de sua eficácia (PESSINI et al., 2003). AYRES et al. (2008) afirma que a busca de substâncias com atividades antimicrobianas tem direcionado a atenção sobre os produtos naturais e, entre estes, os derivados das plantas superiores têm, nos últimos anos, despertado a investigação para o potencial da flora brasileira. Byrsonima pachyphylla Griseb é uma árvore típica do cerrado. Na medicina popular, a casca é utilizada como antifebril, contra tosses e doenças pulmonares, os ramos com folhas são diuréticos e os frutos são laxantes brandos (SILVA JÚNIOR et al., 2005). Levantamento no NAPRALERT indicou que espécies deste gênero são comumente empregadas como antiasmáticas, contra a febre e infecção de pele (MENDES et al., 1999). Este trabalho teve como objetivo determinar qual o melhor método de extração, sendo eles a maceração, a maceração dinâmica, a digestão e a digestão + maceração dinâmica, visando à obtenção de extratos brutos de folhas de Byrsonima pachyphylla Griseb., considerando sua atividade biológica frente a bactéria Gram-positiva: Staphylococcus aureus; as bactérias Gram-negativas: Escherichia coli e Pseudomonas aeruginosa, e a levedura Cândida albicans, testada pelo método de diluição seriada de extratos em microplacas; além de comparar perfis cromatográficos dos extratos obtidos em cromatografia de camada delgada (CCD), bem como pesquisar as principais classes de metabólitos secundários nos extratos. Os resultados obtidos na cromatografia em camada delgada e na triagem fitoquímica preliminar possibilitaram sugerir a presença de taninos, flavonoides, terpenos e saponinas na espécie ...

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The aim of this study was to evaluate the antimicrobial activity and pH changes induced by Portland cement (PC) alone and in association with radiopacifiers. Methods. The materials tested were pure PC, PC + bismuth oxide, PC + zirconium oxide, PC + calcium tungstate, and zinc oxide and eugenol cement (ZOE). Antimicrobial activity was evaluated by agar diffusion test using the following strains: Micrococcus luteus, Streptococcus mutans, Enterococcus faecalis, Pseudomonas aeruginosa, and Candida albicans. After 24 hours of incubation at 37°C, inhibition of bacterial growth was observed and measured. For pH analysis, material samples (n=10) were placed in polyethylene tubes and immersed in 10 mL of distilled water. After 12, 24, 48, and 72 hours, the pH of the solutions was determined using a pH meter. Results. All microbial species were inhibited by the cements evaluated. All materials composed of PC with radiopacifying agents promoted pH increase similar to pure Portland cement. ZOE had the lowest pH values throughout all experimental periods. Conclusions. All Portland cement-based materials with the addition of different radiopacifiers (bismuth oxide, calcium tungstate, and zirconium oxide) presented antimicrobial activity and pH similar to pure Portland cement.

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The aim of this study was to evaluate the pH and antimicrobial activity of micro or nanoparticulate zinc oxide (ZnO) pastes with or without calcium hydroxide (CH). The following medications were evaluated: microparticulate ZnO + polyethylene glycol (PEG) 400; nanoparticulate ZnO + PEG 400; PEG 400; CH + microparticulate ZnO + PEG 400 and CH + nanoparticulate ZnO + PEG 400. The pH was assessed between 12 hours and 28 days, using a digital pH meter. The antimicrobial activity against Enterococcus faecalis (ATCC-9212), Candida albicans (ATCC-10231), Pseudomonas aeruginosa (ATCC-27853), Staphylococcus aureus (ATCC-6538) and Kocuria rhizophila (ATCC-9341) was determined in triplicate using agar diffusion test. The results were submitted to Kruskal-Wallis/Dunn and ANOVA/Tukey tests with 5% significance. The highest pH values were found for CH+ZnO, with higher values for nanoparticulate ZnO after 12 hours and 21 days (p<0.05). CH+ZnO medication promoted higher growth inhibition against P. aeruginosa and lower against E. faecalis. Calcium hydroxide pastes have higher pH and antimicrobial activity when associated with either micro- or nanoparticulate zinc oxide.

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A resistência do biofilme endodôntico pode requerer um período maior de permanência da medicação intracanal a fim de prolongar sua ação antimicrobiana. O objetivo deste estudo foi avaliar a ação antimicrobiana residual das medicações intracanal: G1) hidróxido de cálcio + soro; G2) Calen; G3) Calen + PMCC; G4) Calen + clorexidina 0,4% e G5) clorexidina gel 2% frente à Enterococcus faecalis, Candida albicans, Pseudomonas aeruginosa, Staphylococcus aureus e Kocuria rhizophila em 60 canais radiculares bovinos. Os canais radiculares foram instrumentados e preenchidos com as medicações intracanal, as quais foram removidas após os períodos experimentais (15, 30, 60 e 90 dias) e empregadas na técnica de difusão em ágar. Os halos de inibição foram evidenciados por gel de TTC e então mensurados. Os dados de halos de inibição foram submetidos à análise estatística dos testes Kruskall-Wallis e Dunn, com nível de significância de 5%. O Ca(OH)2 + soro apresentou efeito até o período de 15 dias. A pasta Calen demonstrou efeito residual aos 60 dias frente ao S. aureus, enquanto Calen/PMCC até o período de 90 dias frente à S. aureus e K. rhizophila e aos 30 dias para E. faecalis. A pasta Calen associado à clorexidina foi efetiva frente à E. faecalis até o período de 60 dias. A clorexidina gel 2% apresentou ação residual em todos os períodos, com exceção de E. faecalis aos 90 dias, também apresentou atividade antimicrobiana mais prolongada, seguido das associações do hidróxido de cálcio com clorexidina e PMCC.

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The antimicrobials products from plants have increased in importance due to the therapeutic potential in the treatment of infectious diseases. Therefore, we aimed to examine the chemical characterisation (GC-MS) of essential oils (EO) from seven plants and measure antibacterial activities against bacterial strains isolated from clinical human specimens (methicillin-resistant Staphylococcus aureus (MRSA) and sensitive (MSSA), Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium) and foods (Salmonella Enteritidis). Assays were performed using the minimal inhibitory concentration (MIC and MIC90%) (mg/mL) by agar dilution and time kill curve methods (log CFU/mL) to aiming synergism between EO. EO chemical analysis showed a predominance of terpenes and its derivatives. The highest antibacterial activities were with Cinnamomun zeylanicum (0.25 mg/mL on almost bacteria tested) and Caryophyllus aronzaticus EO (2.40 mg/mL on Salmonella Enteritidis), and the lowest activity was with Eugenia uniflora (from 50.80 mg/mL against MSSA to 92.40 mg/mL against both Salmonella sources and P aeruginosa) EO. The time kill curve assays revealed the occurrence of bactericide synergism in combinations of C. aromaticus and C. zeylanicum with Rosmarinus. officinalis. Thus, the antibacterial activities of the EO were large and this can also be explained by complex chemical composition of the oils tested in this study and the synergistic effect of these EO, yet requires further investigation because these interactions between the various chemical compounds can increase or reduce (antagonism effect) the inhibitory effect of essential oils against bacterial strains.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)