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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Antibacterial Activity of Cardiotoxins from Naja naja atra and Naja nigricollis Venom

Chen, Li-wen 08 June 2011 (has links)
The aim of the study is to investigate the causal relationship between membrane-damaging activity and antibacterial action of cardiotoxins from Naja naja atra (Taiwan cobra) cardiotoxin 3 (CTX3) and Naja nigricollis (Egyptian cobra) toxin gamma. Compared with that on Escherichia coli (E. coli, Gram-negative bacteria), CTX3 showed a greater growth inhibition on Staphylococcus aureus (S. aureus, Gram-positive bacteria). Antibacterial avtivity of toxin gamma toward E. coli and S. aureus was similar. Bactericidal action of cardiotoxins positively correlated with increase in membrane permeability of bacterial cells. Morphological examination showed that cardiotoxins disrupted the integrity of bacterial membrane. Cardiotoxins showed similar binding capability with lipopolysaccharide (LPS) and lipoteichoic acid (LTA), and destabilization of LPS layer and inhibition of LTA biosynthesis on cell wall promoted bactericidal effect of cardiotoxins on E. coli and S. aureus, respectively. CTX3 notably permeabilized model membrane of S. aureus and toxin gamma had similar activity on the permeabilization of bacterial model membrane used. Membrane-damaging activity of cardiotoxins was inhibited by either LPS or LTA, while increasing concentrations of cardiotoxins counteracted the inhibitory action of LPS and LTA. Oxidation of Met residues on loop II of cardiotoxins simultaneously attenuated membrane-permeabilizing activity and bactericidal effect of cardiotoxins. Taken together, our data indicate that antibacterial action of cardiotoxins depend on their ability to induce membrane permeability.
2

ComposiÃÃo quÃmica e avaliaÃÃo do potencial antimicrobiano dos Ãleos essencias de Ruellia asperulla (Mart. ex ness) Lindau e Ruellia paniculata L. (Acanthaceae) / Chemical composition and evaluation of antimicrobial potential of oils of Ruellia asperulla (Mart. ex ness) Lindau e Ruellia paniculata L. (Acanthaceae)

Ariana Azevedo Vasconcelos 22 April 2014 (has links)
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O gÃnero Ruellia L., compreende aproximadamente 300 espÃcies, as quais estÃo amplamente distribuÃdas nas regiÃes tropicais e subtropicais do planeta. Dentre as espÃcies que compÃem o gÃnero, estÃo Ruellia asperula e Ruellia paniculata, conhecidas popularmente como âMelosaâ e âMelosa-roxaâ. Pesquisas fitoquÃmicas e de atividade antimicrobiana sobre as espÃcies pertencentes ao gÃnero Ruellia sÃo escassas, entretanto a literatura revela que algumas dessas espÃcies sÃo largamente empregadas na medicina popular. Assim, o presente trabalho buscou descrever a composiÃÃo quÃmica e avaliar o efeito antibacteriano dos Ãleos essenciais das partes aÃreas de Ruellia asperula e Ruellia paniculata, sobre o crescimento de Streptococcus mutans ATCC 25175, Streptococcus oralis ATCC 10557, Streptococcus parasanguinis ATCC 903, Streptococcus salivarius ATCC 7073, Streptococcus sobrinus ATCC 6715, Pseudomonas aeruginosa ATCC 9027 e Klebsiella oxytoca ATCC 13182, tanto na forma planctÃnica como na de biofilmes. Os Ãleos essenciais foram obtidos e seus constituintes analisados por cromatografia de gÃs e espectrometria de massa (CG/MS). Diferentes metodologias foram empregadas para a verificaÃÃo do potencial antimicrobiano. Dentre estas estÃo a determinaÃÃo da concentraÃÃo inibitÃria mÃnima (CIM), determinaÃÃo da curva de morte e avaliaÃÃo da concentraÃÃo bactericida mÃnima (CBM). AlÃm disso, a quantificaÃÃo da biomassa e do nÃmero de cÃlulas viÃveis do biofilme foram realizadas, respectivamente, atravÃs da coloraÃÃo pelo cristal violeta e contagem de unidades formadoras de colÃnia (UFC). Os controles negativo e positivo utilizados em todos os ensaios foram, respectivamente, DMSO 4% e Gluconato de Clorexidina com concentraÃÃo ajustada de acordo com os dados da CIM de cada micro-organismo. Os principais constituintes do Ãleo de R. asperula foram cariofila-4(12),8(13)-dien-5β-ol (14,1%), (E)-cariofileno (22,7%) e Ãxido de cariofileno (29,4%), enquanto (E)-cariofileno (11,0%), espatulenol (13,1%) e δ-amorfeno (14,9%), foram os constituintes majoritÃrios do Ãleo de R. paniculata. Os dados mostraram que os Ãleos testados exerceram melhores resultados sobre as linhagens de bactÃrias Gram-positivas, e que o Ãleo essencial de R. paniculata apresentou o melhor efeito sendo capaz de inibir o crescimento planctÃnico, bem como o desenvolvimento de biofilmes da cepa de S. oralis. Assim, os Ãleos essenciais de R. asperula e R. paniculata surgem como importantes alternativas para o controle bacteriano. / The genus Ruellia L. comprises about 300 species, which are broadly distributed in tropical and subtropical regions of the planet. Among the species that comprise the genus, are Ruellia asperula and Ruellia paniculata, known popularly as "Melosa" and "Melosa-purple". Phytochemical research and antimicrobial activity against species belonging to the genus Ruellia are scarce, however the literature reveals that some of these species are widely used in folk medicine. Thus, this study sought to describe the chemical composition and evaluate the antibacterial effect of essential oils from aerial parts of Ruellia asperula and Ruellia paniculata, on the growth of Streptococcus mutans ATCC 25175, Streptococcus oralis ATCC 10557, Streptococcus parasanguinis ATCC 903, Streptococcus salivarius ATCC 7073, Streptococcus sobrinus ATCC 6715, Pseudomonas aeruginosa ATCC 9027 e Klebsiella oxytoca ATCC 13182, both in planktonic form as in biofilms. The essential oils were obtained and their constituents analyzed by gas chromatography and mass spectrometry (GC / MS). Different methodologies were used to check the antimicrobial potential. Among these are the minimum inhibitory concentration (MIC) determination of the death curve and evaluation of minimum bactericidal concentration (MBC). Furthermore, quantification of biomass and the number of viable cells in the biofilm were conducted, respectively, by staining with crystal violet and counting of colony forming units (CFU). The negative and positive controls used in all tests were, respectively, 4% DMSO and chlorhexidine gluconate adjusted according to the concentration data from the MIC of each micro-organism. The main constituents of the oil R. asperula were cariophylla-4 (12)-8-(13)-dien-5β-ol (14.1%), (E)-caryophyllene (22.7%) and caryophyllene oxide (29.4%) as (E)-caryophyllene (11.0%), spathulenol (13.1%) and δ-amorphene (14.9%) were the major constituents of oil R. paniculata. The data showed that the tested oils have had best results on the strains of Gram-positive bacteria, the essential oil of R. paniculata showed the best effect being able to inhibit planktonic growth, and the development of biofilms of S. oralis strain. Thus, the essential oils and R. asperula and R. paniculata emerge as important alternatives to control bacterial.
3

Atividade antibacteriana in vitro e in vivo de Schinus terebinthifolius Raddi no controle da mastite bovina / Atividade antibacteriana in vitro e in vivo de Schinus terebinthifolius Raddi no controle da mastite bovina

Faccin, ângela 22 February 2013 (has links)
Made available in DSpace on 2014-08-20T14:37:52Z (GMT). No. of bitstreams: 1 dissertacao_angela_faccin.pdf: 701455 bytes, checksum: 1aba9406a434f486abae1d2bd069feeb (MD5) Previous issue date: 2013-02-22 / The scientific interest in herbal medicine has led to the development of research based on the popular practices. This study aimed to evaluate the antibacterial activity of the hydroalcoholic extract and essential oil from the leaves and fruits of Schinus terebinthifolius Raddi at two growth stages against bacteria related to bovine mastitis, besides testing a plant extract with antibacterial action, to be used antisepsis in milking. The thesis is presented in two papers. The first refers to the in vitro antibacterial activity of hydroalcoholic extract and essential oil from leaves and fruits at two growth stages, tested by serial microdilution plates against bovine mastitis bacteria. The results were expressed as Minimal Bactericidal Concentration. All extracts showed antibacterial activity. The second paper shows results for the in vivo experiment, which tested the hydroalcoholic extract of the leaves of the plant before and after dipping for twelve consecutive weeks, was used as control iodine commercial, weekly data were collected regarding clinical mastitis, subclinical and new intramammary infections, and biweekly health data sphincter and skin from the ceiling. None of the indices analyzed apresentraram difference between treatments, suggesting that the plant extract can be used to teat antisepsis as a replacement of conventional products. In our study we have obtained satisfactory results from the use of this plant, it has antibacterial activity against bacteria in bovine mastitis and teat disinfection has similar results to the conventional product. / O interesse científico pela fitoterapia levou ao desenvolvimento de pesquisas baseadas nas práticas populares. Este trabalho teve como objetivo avaliar a atividade antibacteriana do extrato hidroalcoólico e óleo essencial das folhas e frutos de Schinus terebinthifolius Raddi em dois estádios fenológicos frente a bactérias relacionadas a mastite bovina, além de testar um extrato da planta, com ação antibacteriana, para ser utilizado na antissepsia da ordenha. A dissertação está apresentada em dois artigos científicos. O primeiro, refere-se a atividade antibacteriana in vitro do extrato hidroalcoólico e óleo essencial das folhas e frutos em dois estádios fenológicos, testados pela técnica de microdiluição serial em placas contra bactérias da mastite bovina. Os resultados foram expressos pela Concentração Bactericida Mínima. Todos os extratos apresentaram atividade antibacteriana. O segundo trabalho demonstra resultados referentes ao experimento in vivo, onde foi testado o extrato hidroalcoólico das folhas da planta no pré e pós dipping, durante doze semanas consecutivas, como controle se utilizou iodo comercial, foram coletados dados semanais referentes a mastite clínica, subclínica, e novas infecções intramamárias, e dados quinzenais da saúde do esfíncter e da pele do teto. Nenhum dos índices analisados apresentraram diferença estatísticas entre os tratamentos, sugerindo que o extrato da planta pode ser usado para antissepsia dos tetos como substituinte dos produtos convencionais. Em nosso estudo obtivemos resultados satisfatórios da utilização desta planta, ela apresenta ação antibacteriana frente as bactérias da mastite bovina e na desinfecção dos tetos tem resultados semelhantes aos do produto convencional.
4

Efeito antibacteriano dos sistemas Self-Ajusting File, XP-endo finisher e irrigação ultrassônica passiva sobre biofilme de Enterococcus faecalis / Effectiveness of Self-Adjusting File, XP-endo Finisher and passive ultrasonic irrigation in bacterial root canal control

Sousa, Vinicius Caixeta de 19 April 2016 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-10T11:30:57Z No. of bitstreams: 2 Dissertação - Vinicius Caixeta de Sousa - 2016.pdf: 6443318 bytes, checksum: 09bb12a456ef519b05b09ed648a75811 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-10T11:31:28Z (GMT) No. of bitstreams: 2 Dissertação - Vinicius Caixeta de Sousa - 2016.pdf: 6443318 bytes, checksum: 09bb12a456ef519b05b09ed648a75811 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-05-10T11:31:28Z (GMT). No. of bitstreams: 2 Dissertação - Vinicius Caixeta de Sousa - 2016.pdf: 6443318 bytes, checksum: 09bb12a456ef519b05b09ed648a75811 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-04-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Abstract: Objective: To evaluate the effectiveness of complementary protocols of sanitization in the decontamination of infected root canals. Methods: Fifty uniradicular maxilary anterior human teeth were selected. The crowns were removed and the lengths standardized at 16 mm. The specimens were inoculated with Enterococcus faecalis and incubated at 37 °C for sixty days. Thirty teeth were performed with BioRace instruments until diameter corresponding to #60.02, and then complemented with Self-Adjusting File (SAF); XP-endo Finisher (XPF) and passive ultrasonic irrigation (PUI). Ten samples were used as positive control and 10 were not contaminated. Initial and final samples were collected and incubated at 37 °C for a period of 48 hours. The bacterial growth was analyzed in culture, determining the presence or absence of bacteria. The optical density of the culture medium was interpreted by UV spectrophotometry. The specimens were sectioned and prepared for evaluation in SEM. The images of the root surfaces were analyzed and classified by scores according to the presence of debris. The Kruskal-Wallis test was used for statistical analysis. The level of significance was 5%. Results: The mean optical density (μm) of the sanification protocols showed bacterial reduction in all groups. The experimental groups did not present statistically significant differences (p = 0.196). The analysis of SEM images revealed no significant difference (p = 0.414) between the scores of the groups. Conclusion: Complementary sanitization protocols reduced bacterial contamination. / Resumo: Objetivo: Avaliar a efetividade de protocolos complementares de sanificação na descontaminação de canais radiculares infectados. Materiais e métodos: Cinquenta dentes humanos anteriores superiores unirradiculares foram selecionados. As coroas foram removidas e os comprimentos padronizados em 16 mm. Os espécimes foram inoculados com Enterococcus faecalis e incubados a 37°C por sessenta dias. Trinta dentes foram preparados com instrumentos BioRace até alcançar o diâmetro correspondente ao #60.02, e a seguir complementados com Self-Adjusting File (SAF); XP-endo Finisher (XPF) e irrigação ultrassônica passiva (PUI). Dez amostras foram usadas como controle positivo e 10 não foram contaminadas. Amostras inicial e final foram coletadas e incubadas a 37°C por um período de 48 horas. O crescimento bacteriano foi analisado em cultura, determinando a presença ou ausência de bactérias. A densidade óptica do meio de cultura foi interpretada por espectrofotometria UV. Os espécimes foram seccionados e preparados para avaliação em MEV. A análise das imagens das superfícies radiculares foram analisadas e classificadas em scores de acordo com a presença de debris. O teste de Kruskal-Wallis foi utilizado para as análises estatísticas. O nível de significância foi 5%. Resultados: A média da densidade óptica (μm) dos protocolos de sanificação revelou redução bacteriana em todos os grupos. Os grupos experimentais não apresentaram diferenças estatisticamente significante (p=0,196). A análise das imagens de MEV revelou ausência de diferença significante (p=0,414) entre os scores dos grupos. Conclusão: Os protocolos complementares de sanificação favoreceu a redução da contaminação bacteriana.

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