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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.
31

Estudo dos mecanismos de resistência e virulência de isolados de Cryptococcus neoformans e Cryptococcus gattii e quantificação de genes de bomba de efluxo pós tratamento com Galatos de Alquila /

Rossi, Suélen Andreia. January 2014 (has links)
Orientador : Ana Marisa Fusco Almeida / Coorientador: Maria José Soares Mendes Giannini / Banca: Juliana Campos Junqueira / Banca: Fernando Rogério Pavan / Banca: Patricia Albuquerque de Andrade Nicola / Banca: Dulce Helena Siqueira Silva / Resumo: O aumento de micoses invasivas e o desenvolvimento de mecanismos de resistência de algumas espécies de fungos, frente aos fármacos utilizados na terapia, têm sido preocupante. O tratamento antifúngico, geralmente é agressivo e o surgimento da resistência antifúngica acrescenta dificuldades adicionais no tratamento dessas infecções. Cryptococcus neoformans e Cryptococcus gattii são os principais agentes etiológicos da criptococose, e afetam principalmente pacientes imunodeprimidos. Nesse trabalho foi realizada a caracterização morfológica e da virulência de três isolados clínicos de C. neoformans e dois isolados ambientais de C. gattii em Galleria mellonella, além da análise do nível de expressão dos genes MDR1 e AFR1 envolvidos no funcionamento de bomba de efluxo, através da quantificação relativa por PCR (polimerase chain reaction) em tempo real. Uma vez esses genes quantificados, esses isolados foram usados na prospecção de moléculas sintéticas para verificação da atividade inibitória dos genes selecionados, após o contato com as mesmas. Os isolados foram classificados como sensível (26S), sensibilidade intermediária (27I) e resistente (30R) da espécie neoformans e da espécie C. gattii, um foi resistente (118R) e outro sensível (CL), in vitro, a fluconazol. As moléculas selecionadas para os testes foram o ácido gálico e seus derivados sintéticos, e os melhores resultados observados foram obtidos a partir dos galatos de alquila G11, G12, G14, G15, G16 e G17, apresentando ótima atividade antifúngica contra os isolados testados, em especial os galatos G14, G16 e G17, obtendo ótima atividade antifúngica. O galato de n-dodecila (G16), foi selecionado para os demais testes apresentando atividade aditiva no teste de sinergismo, quando utilizado em associação com fluconazol, reduzindo os valores de CIM para o mesmo, o que mostra a possível... / Abstract: The increase of invasive mycoses and the development of antifungal resistance by some fungi species have been worrying. The antifungal treatment is usually aggressive and inefficient, and the emergence of antifungal resistance increases the difficulties in treating these fungi infections.Cryptococcus neoformans e Cryptococcus gattii are the main etiologic agents of cryptococcosis andespecially affect immunocompromised patients. In this work the Galleria mellonella, was used to perform the morphologic characterization as well as determine the virulence of three sequential clinical isolates of C. neoformansand twoisolates environmental of C. gattii. In addition, was held the analysis of genes expressions (MDR1, ERG11 and AFR1), that are involved in efflux pumps and ergosterol synthesis, by real time PCR (polimerase chain reaction) assay. After these characterizations the isolates were used in the prospecting of synthetic molecules to verify the inhibitory activity of selected genes. After incubation in vitro with fluconazole the C.neoformans isolates were classified as sensitive (26S), intermediate sensitivity (27I) and resistant (30R), and the C. gattiiisolates were resistant (118R) and the other sensitive (LC). The galic acid molecules and their synthetic derivatives were tests against C.neoformans and C. gattii isolates.The best results were obtained from alkyl gallates G11, G12, G14, G15, G16 and G17 which shows a great antifungal activity, especially G14, G16 e G17. The gallate n-dodecyl (G16), was select to others tests once presented additive activity in synergism test with fluconazole, decreasing the MIC values. The gene expression assay shows that both isolates expressed MDR1 and AFR1 (encoding efflux pumps), and the G16 was capable to inhibit these genes which makes this molecule promising for inhibiting efflux. With virulence assays using the G. mellonella was possible ... / Doutor
32

Role of MAP Kinase in Fusarium Association With Contact Lenses

Danboise, Brook Alicia 17 November 2008 (has links)
Fusarium solani is a soil-borne pathogen devastating agricultural crops throughout the world. While most pathogens are host specific, the fusaria are able to infect both plants and animals. In 2004, an outbreak of Fusarium occurred in association with contact lens wear. Several species of Fusarium were involved but F. solani and F. oxysporum were most prominent. In this work, we have identified a MAP kinase (MAPK), highly similar to fmk1 in F. oxysporum, belonging to the YERK1 subfamily of extracellular regulated kinases. Directed disruption of fmk1 in F. solani AFR4 (FSSC 1) affected several aspects of fungal growth and pathogenicity. Colonies of AFR4„½fmk1 displayed pigmented colony-like formation as opposed to the cottony-white diffuse growth observed with the wild-type strain. Mutants displayed changes in morphology and conidiation patterns with AFR4„½fmk1 mutants producing increased amounts of macroconidia vs. microconidia. AFR4„½fmk1 germ tube emergence was similar to that of wild-type AFR4 and wet weight growth was equivalent but germinules were not able to sense nutrient in chemotropic assays. The disruption of fmk1 increased spore surface hydrophobicity leading to a decrease in association with commercially available hydrogel contact lenses. FMK1 did not affect unworn lens penetration in phosphate buffered saline as both wild-type and mutant strains were able to penetrate commercially available silicone hydrogel contact lenses. AFR4 displayed increased penetration of silicone lenses and this is likely due to: increased spore/lens association, and the inability of AFR4„½fmk1 macroconidia to germinate in phosphate buffered saline. Diminished invasive growth was also noted with disruption of fmk1. Wild-type AFR4 was detected throughout the eye after conidial microinjection while AFR4„½fmk1 was limited to the vitreous fluid. The reduced invasive growth seen is attributed to the loss of chemotropism. The ability to sense and respond to the environment is essential for pathogenicity. MAPK has been deemed essential for plant pathogenicity and now, with its affect on chemotropism, appears to be necessary for animal pathogenicity. FMK1 plays a conserved role in the pathogenicity of Fusarium.
33

Estudo dos mecanismos de resistência e virulência de isolados de Cryptococcus neoformans e Cryptococcus gattii e quantificação de genes de bomba de efluxo pós tratamento com Galatos de Alquila

Rossi, Suélen Andreia [UNESP] 28 November 2014 (has links) (PDF)
Made available in DSpace on 2015-12-10T14:24:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-11-28. Added 1 bitstream(s) on 2015-12-10T14:30:40Z : No. of bitstreams: 1 000851921.pdf: 11886045 bytes, checksum: 1cf15c01de888d44bc38aeeab19c7d88 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O aumento de micoses invasivas e o desenvolvimento de mecanismos de resistência de algumas espécies de fungos, frente aos fármacos utilizados na terapia, têm sido preocupante. O tratamento antifúngico, geralmente é agressivo e o surgimento da resistência antifúngica acrescenta dificuldades adicionais no tratamento dessas infecções. Cryptococcus neoformans e Cryptococcus gattii são os principais agentes etiológicos da criptococose, e afetam principalmente pacientes imunodeprimidos. Nesse trabalho foi realizada a caracterização morfológica e da virulência de três isolados clínicos de C. neoformans e dois isolados ambientais de C. gattii em Galleria mellonella, além da análise do nível de expressão dos genes MDR1 e AFR1 envolvidos no funcionamento de bomba de efluxo, através da quantificação relativa por PCR (polimerase chain reaction) em tempo real. Uma vez esses genes quantificados, esses isolados foram usados na prospecção de moléculas sintéticas para verificação da atividade inibitória dos genes selecionados, após o contato com as mesmas. Os isolados foram classificados como sensível (26S), sensibilidade intermediária (27I) e resistente (30R) da espécie neoformans e da espécie C. gattii, um foi resistente (118R) e outro sensível (CL), in vitro, a fluconazol. As moléculas selecionadas para os testes foram o ácido gálico e seus derivados sintéticos, e os melhores resultados observados foram obtidos a partir dos galatos de alquila G11, G12, G14, G15, G16 e G17, apresentando ótima atividade antifúngica contra os isolados testados, em especial os galatos G14, G16 e G17, obtendo ótima atividade antifúngica. O galato de n-dodecila (G16), foi selecionado para os demais testes apresentando atividade aditiva no teste de sinergismo, quando utilizado em associação com fluconazol, reduzindo os valores de CIM para o mesmo, o que mostra a possível... / The increase of invasive mycoses and the development of antifungal resistance by some fungi species have been worrying. The antifungal treatment is usually aggressive and inefficient, and the emergence of antifungal resistance increases the difficulties in treating these fungi infections.Cryptococcus neoformans e Cryptococcus gattii are the main etiologic agents of cryptococcosis andespecially affect immunocompromised patients. In this work the Galleria mellonella, was used to perform the morphologic characterization as well as determine the virulence of three sequential clinical isolates of C. neoformansand twoisolates environmental of C. gattii. In addition, was held the analysis of genes expressions (MDR1, ERG11 and AFR1), that are involved in efflux pumps and ergosterol synthesis, by real time PCR (polimerase chain reaction) assay. After these characterizations the isolates were used in the prospecting of synthetic molecules to verify the inhibitory activity of selected genes. After incubation in vitro with fluconazole the C.neoformans isolates were classified as sensitive (26S), intermediate sensitivity (27I) and resistant (30R), and the C. gattiiisolates were resistant (118R) and the other sensitive (LC). The galic acid molecules and their synthetic derivatives were tests against C.neoformans and C. gattii isolates.The best results were obtained from alkyl gallates G11, G12, G14, G15, G16 and G17 which shows a great antifungal activity, especially G14, G16 e G17. The gallate n-dodecyl (G16), was select to others tests once presented additive activity in synergism test with fluconazole, decreasing the MIC values. The gene expression assay shows that both isolates expressed MDR1 and AFR1 (encoding efflux pumps), and the G16 was capable to inhibit these genes which makes this molecule promising for inhibiting efflux. With virulence assays using the G. mellonella was possible ...
34

Antifúngicos naturais e sintéticos: estudo dos mecanismos de ação em sistema de infecção in vitro empregando cepas de Cryptococcus

Gullo, Fernanda Patricia [UNESP] 14 February 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-14Bitstream added on 2014-06-13T20:35:39Z : No. of bitstreams: 1 gullo_fp_me_arafcf.pdf: 1209208 bytes, checksum: eb8202940f1c96815dc70f8524aa0063 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A criptococose é uma micose sistêmica e oportunista causada principalmente pelas leveduras Cryptococcus neoformans e Cryptococcus gattii. Entre as principais manifestações clínicas estão o desenvolvimento de meningite, encefalite, meningoencefalite e infecções pulmonares. Estima-se que mais de um milhão dos casos de criptococose ocorrem por ano em indivíduos HIV positivos, o que classifica esta doença como a terceira mais importante entre as infecções fúngicas sistêmicas. A ecologia deste gênero está diretamente relacionada ao meio ambiente, sendo a espécie C. neoformans, comumente encontrada em excretas secas de pombos (Columbia livia) e a espécie C. gattii é encontrada, principalmente, em plantas, como espécies de Eucalyptos. O tratamento da criptococose é realizado com os fármacos antifúngicos, anfotericina B e fluconazol, sendo este último de ação fungistática utilizado para tratamento de longo prazo, que apesar de eficiente, pode causar uma série de reações adversas e ainda desenvolvimento de resistência. Tendo em vista o difícil controle da levedura e o tratamento, este trabalho tem como objetivo principal, a pesquisa de substâncias naturais com alto potencial antifúngico com finalidade saneante e medicamentosa, combatendo a levedura em seu nicho ecológico natural e também atuando no combate à infecção no hospedeiro. Uma forma de diminuir os casos desta infecção é através do processo de desinfecção ambiental com produtos saneantes, os quais apresentam capacidade fungicida. Por meio do projeto Biota/FAPESP, foram selecionados dois triterpenóides quinonamétideos extraídos de Maytenus ilicifolia, a maitenina e a pristimerina, as quais apresentaram potentes CIMs anti-Cryptococcus, mais de 90 % de eficiência na desinfecção e baixa toxicidade, o que revela que... / Cryptococcosis is a systemic mycosis caused mainly by opportunistic yeast Cryptococcus neoformans and Cryptococcus gattii. Among the main clinical manifestations are the development of encephalitis, meningoencephalitis and pulmonar infections. It is estimated that more than one million cases of cryptococcosis occur per year in HIV positive individuals, which classifies the disease as the third among the most importante systemic fungal infections. The ecology of this genus is directly related to the environment. Specie C. neoformans is commonly found in dried excremento of pigeons (Columbia livia) and the species C. gattii is found primarily in plants such as Eucalyptus species. Cryptococcosis treatment is performed with the antifungal drugs amphotericin B and fluoconazole, the later being of a fungistatic used to treat long-term, while effective, may cause a number of adverse reactions and also the development of resistence. Given the difficult control of the yeast and treatment, this work has as main objective, the research of natural substances with high potential antifungal drug with purpose and saneante, fighting yeast in their natural ecological niche and also acting in fighting infection in the host. One way to reduce the cases of infection is through the capacity fungicide. Through the Project BIOTA / FAPESP, we selected two quinonametides triterpenids extracted from Maytenus ilicifolia, the maitenin and pristimerin, which showed potente anti-Cryptococcus MICs, more than 90 % of the disinfection efficiency and low toxicity... (Complete abstract click electronic access below)
35

Isolamento ambiental e caracterização bioquímica de Cryptococcus / Environmental isolation and biochemical characterization of Cryptococcus

Destro, Mariana Malavazi [UNESP] 03 June 2016 (has links)
Submitted by MARIANA MALAVAZI DESTRO null (m_destro@hotmail.com) on 2016-07-07T16:27:57Z No. of bitstreams: 1 Dissertação para arquivar Unesp.pdf: 751238 bytes, checksum: ef14aad090e2f5e2974329d58301aef8 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-07-11T14:37:52Z (GMT) No. of bitstreams: 1 destro_mm_me_araca.pdf: 751238 bytes, checksum: ef14aad090e2f5e2974329d58301aef8 (MD5) / Made available in DSpace on 2016-07-11T14:37:52Z (GMT). No. of bitstreams: 1 destro_mm_me_araca.pdf: 751238 bytes, checksum: ef14aad090e2f5e2974329d58301aef8 (MD5) Previous issue date: 2016-06-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A criptococose é uma infecção fúngica causada por levedura do gênero Cryptococcus. Dentre as principais micoses sistêmicas nas últimas décadas, a criptococose vem assumindo um relevante papel, com altos índices de morbidade e mortalidade principalmente em pacientes imunodeprimidos. O presente trabalho teve por objetivo verificar a ocorrência de Cryptococcus spp. em amostras ambientais na área urbana de Bauru-SP, Brasil, estabelecendo os focos ambientais, com a finalidade de compreender a eco-epidemiologia do microrganismo. Cinquenta amostras ambientais de dez locais representativos foram processadas e semeadas em ágar semente de Níger (NSA) e Sabouraud. As colônias com características macro e micromorfológicas compatíveis com Cryptococcus foram submetidas a provas bioquímicas, sendo que 12/50 (24%) das amostras foram positivas para o gênero Cryptococcus. A partir dos resultados obtidos, pode-se concluir que foram encontradas espécies causadoras de criptococose no município de Bauru, constituindo-se na existência de focos ambientais, com potencial patogênico para o homem e animais. A compreensão da eco-epidemiologia do Cryptococcus constitui em uma importante ferramenta na estratégia de medidas preventivas. / Cryptococcosis is a fungal infection caused by yeasts of the genus Cryptococcus. One of the main systemic mycoses in recent decades, has been assuming an important role, with high rates of morbidity and mortality especially in immunosuppressed patients. The present study aimed to verify the existence of Cryptococcus spp. from environmental samples in the urban area of Bauru-SP, Brazil, establishing the environmental focus, with the purpose of understand the eco-epidemiology of the micro-organism. Fifty environmental samples from ten representative sites were processed and seeded in agar Niger seed (NSA) and Sabouraud. The colonies with macro and micromorphological compatible with Cryptococcus underwent biochemical tests, and 12/50 (24%) of the samples were positive for the genus Cryptococcus. From the results obtained, it can be concluded that species that cause cryptococcosis were found in the city of Bauru-SP, Brazil, constituting the existence of outbreaks with potential environmental pathogenic for human and animals. The eco-epidemiological understanding of the Cryptococcus constitutes an important tool in the strategy of preventive measures.
36

Antifúngicos naturais e sintéticos : estudo dos mecanismos de ação em sistema de infecção in vitro empregando cepas de Cryptococcus /

Gullo, Fernanda Patricia. January 2012 (has links)
Orientador: Ana Marisa Fusco de Almeida / Coorientador: Maria José Soares Mendes Giannini / Banca: Maristela Pereira / Banca: Luis Octávio Regasini / Resumo: A criptococose é uma micose sistêmica e oportunista causada principalmente pelas leveduras Cryptococcus neoformans e Cryptococcus gattii. Entre as principais manifestações clínicas estão o desenvolvimento de meningite, encefalite, meningoencefalite e infecções pulmonares. Estima-se que mais de um milhão dos casos de criptococose ocorrem por ano em indivíduos HIV positivos, o que classifica esta doença como a terceira mais importante entre as infecções fúngicas sistêmicas. A ecologia deste gênero está diretamente relacionada ao meio ambiente, sendo a espécie C. neoformans, comumente encontrada em excretas secas de pombos (Columbia livia) e a espécie C. gattii é encontrada, principalmente, em plantas, como espécies de Eucalyptos. O tratamento da criptococose é realizado com os fármacos antifúngicos, anfotericina B e fluconazol, sendo este último de ação fungistática utilizado para tratamento de longo prazo, que apesar de eficiente, pode causar uma série de reações adversas e ainda desenvolvimento de resistência. Tendo em vista o difícil controle da levedura e o tratamento, este trabalho tem como objetivo principal, a pesquisa de substâncias naturais com alto potencial antifúngico com finalidade saneante e medicamentosa, combatendo a levedura em seu nicho ecológico natural e também atuando no combate à infecção no hospedeiro. Uma forma de diminuir os casos desta infecção é através do processo de desinfecção ambiental com produtos saneantes, os quais apresentam capacidade fungicida. Por meio do projeto Biota/FAPESP, foram selecionados dois triterpenóides quinonamétideos extraídos de Maytenus ilicifolia, a maitenina e a pristimerina, as quais apresentaram potentes CIMs anti-Cryptococcus, mais de 90 % de eficiência na desinfecção e baixa toxicidade, o que revela que... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Cryptococcosis is a systemic mycosis caused mainly by opportunistic yeast Cryptococcus neoformans and Cryptococcus gattii. Among the main clinical manifestations are the development of encephalitis, meningoencephalitis and pulmonar infections. It is estimated that more than one million cases of cryptococcosis occur per year in HIV positive individuals, which classifies the disease as the third among the most importante systemic fungal infections. The ecology of this genus is directly related to the environment. Specie C. neoformans is commonly found in dried excremento of pigeons (Columbia livia) and the species C. gattii is found primarily in plants such as Eucalyptus species. Cryptococcosis treatment is performed with the antifungal drugs amphotericin B and fluoconazole, the later being of a fungistatic used to treat long-term, while effective, may cause a number of adverse reactions and also the development of resistence. Given the difficult control of the yeast and treatment, this work has as main objective, the research of natural substances with high potential antifungal drug with purpose and saneante, fighting yeast in their natural ecological niche and also acting in fighting infection in the host. One way to reduce the cases of infection is through the capacity fungicide. Through the Project BIOTA / FAPESP, we selected two quinonametides triterpenids extracted from Maytenus ilicifolia, the maitenin and pristimerin, which showed potente anti-Cryptococcus MICs, more than 90 % of the disinfection efficiency and low toxicity... (Complete abstract click electronic access below) / Mestre
37

Avaliação por métodos fenotípicos e proteômicos de galatos de alquila com atividade anti-complexo Paracoccidioides /

Silva, Ana Carolina Alves de Paula e. January 2012 (has links)
Orientador: Maria José Soares Mendes Giannini / Banca: Luis Octávio Regasini / Banca: Eduardo Bagagli / Resumo: Paracoccidioides brasiliensis e P. lutzii são fungos dimórficos, agentes etiológicos da paracoccidioidomicose, que é uma micose humana sistêmica geograficamente confinada na América Latina. Vários antifúngicos podem ser utilizados para o tratamento dessa doença, tais como anfotericina B, sulfamídicos e azólicos (itraconazol) e de maneira geral seu uso é prolongado. As limitações frequentes dos antifúngicos e o aumento na incidência das infecções fúngicas sistêmicas têm ressaltado a necessidade da descoberta e do desenvolvimento de novos fármacos. O objetivo deste estudo foi comparar a atividade antifúngica de anfotericina B, itraconazol e galatos de alquila anti-complexo de Paracoccidioides por métodos fenotípicos e proteômicos. Para tanto foi padronizado o teste de sensibilidade para selecionar o galato de maior potência, utilizando o documento M27-A2 (2002), modificado pela adição de Alamar Blue. Adicionalmente, análises proteômicas foram realizadas antes e após tratamento com o antifúngico selecionado para verificar o perfil das possíveis proteínas-alvo. A atividade antifúngica foi estudada contra isolados de P. brasiliensis (S1, S2 e PS3) e P. lutzii, (Pb01-like), e depois o teste foi estendido para mais seis isolados. O valor da CIM do ácido gálico variou de 31,25 a 0,250 mg/L para todos os isolados. Os galatos mostraram valores de CIM entre 16 a 0,004 mg/L. O menor valor de CIM foi observado para seis galatos que possuem uma substituição por uma cadeia relativamente longa de carbonos. O perfil proteico dos isolados Pl01 e Pb18 foi estudado por eletroforese 2D após contato com anfotericina B , itraconazol e o galato de decila (todos a uma concentração de 0,125 mg/L. Mais de 130 spots para ambos os fungos foram observados e a maioria destas proteínas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Paracoccidioides brasiliensis and P. lutzii are dimorphic fungi, etiological agents of paracoccidioidomycosis, which is a systemic human mycosis geographically restricted to Latin America. Various antifungal agents may be used to treat this disease, such as amphotericin B, sulfamidic agents and itraconazole, and these drugs are used in long-term therapies. The limitations of antifungals and increased incidence of systemic fungal infections has underscored the need for discovery and development of new drugs. The objective of this study was to compare the antifungal activity of amphotericin B, itraconazole and alkyl gallates anti-Paracoccidioides complex by phenotypic and proteomic methods. Thus, the susceptibility test was applied to select the most potent gallate, using the document M27-A2 (2002), modified by the addition of Alamar Blue. Finally, proteomic analyses was developed before and after the treatment with the antifungal agent selected, to study the protein profile after this treatment. The antifungal activity was evaluated against isolates of P. brasiliensis (S1, S2 and PS3) and P. lutzii (PB01-like), and after, the test has been extended to six isolates. The MIC values of gallic acid varied from 31.25 to 0.250 mg/L for all isolates. The gallates showed MIC values ranging from 16 to 0,004 mg/L. The lowest MIC value was observed for six gallates bearing a substitution for a long side chain. The protein profile of isolates Pb18 and Pl01 was studied by 2D electrophoresis after contact with amphotericin B, itraconazole and decyl gallate, all in the concentration of (0.125 mg/L ). More than 130 spots for both species were observed, and the most of these proteins... (Complete abstract click electronic access below) / Mestre
38

Caracterização dos biofilmes de dermatófitos e desenvolvimento de protótipos antidermatófitos nas formas planctônica e biofilme /

Orlandi, Caroline Barcelos Costa. Unknown Date (has links)
Orientador: Maria José Soares Mendes Giannini / Orientador no exterior: Joshua Daniel Nosanchuk / Coorientador: Ana Marisa Fusco Almeida / Banca: Carlos Pelleschi Taborda / Banca: Mauro Cintra Giudice / Banca: Marlus Chorilli / Banca: Maria Aparecida de Resende Stoianoff / Resumo: Dermatófitos são fungos que apresentam a capacidade de invadir os tecidos queratinizados do homem e dos animais, produzindo a dermatofitose. Biofilmes são comunidades estruturadas de microrganismos que se agrupam de maneira organizada a uma superfície ou que se aderem uns aos outros, dentro de uma matriz extracelular que eles mesmos produzem. Pela primeira vez, neste trabalho, foi descrita a formação de biofilmes por isolados clínicos e cepas ATCC de dermatófitos. Também se avaliou a sensibilidade das cepas frente aos antifúngicos convencionais e derivados sintéticos do ácido protocatecuico, determinando sua toxicidade e eficiência, tanto nas formas planctônicas como de biofilme. A identificação molecular dos isolados clínicos mostrou concordância com a identificação convencional. Todas as cepas e isolados foram capazes de formar biofilmes nos quatro meios testados. Trichophyton. rubrum ATCC 28189, ATCC MYA-4438, T. rubrum 143 e Trichophyton. mentagrophytes 66 produziram mais biomassa e matriz extracelular que T. mentagrophytes ATCC 11481 (p<0.05). RPMI 1640, BHI e DMEM estimularam maior produção de biomassa e matriz extracelular que o meio de queratinócitos. Todas as espécies foram capazes de formar biofilmes maduros em 72 h e uma rede de hifas circundadas em vários pontos por uma matriz extracelular foi mostrada por microscopia eletrônica de varredura (MEV). Na microscopia confocal, aparentemente os meios RPMI e DMEM produziram biofilmes mais espessos e o meio BHI, biofilmes mais densos e compactos. As melhores atividades anti-dermatófitos foram expressas pelos protocatecuatos de butila, pentila, hexila, nonila e decila, que exibiram baixa toxicidade para as células HaCat, NHOK e HepG2 nas regiões da concentração inibitória mínima (CIM). Nonila foi... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Dermatophytes are fungi that have the ability to invade keratinized tissues of human and animals, producing a condition called dermatophytosis. Biofilms are structured microbial communities that are organized by adhering to a surface, as well as to each other via an extracellular polymeric matrix. For the first time, in this work, the biofilm formation by ATCC strains and clinical isolates of dermatophytes was described. Also, the susceptibilities of the strains to conventional antifungal drugs and to the synthetic derivatives of protocatechuic acid were evaluated, determining its toxicity and efficacy. The molecular identification corroborated with the conventional one. All strains were able to form biofilms in the four media tested. Trichophyton. rubrum ATCC 28189, Trichophyton. mentagrophytes 66, and T. rubrum 143 produced more biomass, polysaccharide structures and extracellular matrix than T. mentagrophytes ATCC 11481 (p <0.05). RPMI 1640, BHI and DMEM stimulated increased production of biomass and extracellular matrix when compared to the medium for keratinocytes. All species were able to form mature biofilms in 72 hours. The SEM results showed a coordinated network of hyphae in all directions, surrounded by an extracellular matrix. In confocal microscopy, apparently RPMI and DMEM media produced thicker biofilms, while the BHI produced denser and compact biofilms. The greatest antidermatophytes activities were expressed by butyl, pentyl, hexyl, nonyl and decyl, protocatechuates, which exhibit low toxicity to HaCat, HepG2 and NHOK cells in the regions of minimal inhibitory concentrations (MIC). Nonyl was the compound with improved selectivity index for HaCat and HepG2 cells; for NHOK cells, the most selective compounds were nonyl and hexyl. Fluconazole, griseofulvin... (Complete abstract click electronic access below) / Doutor
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Efeito de terapias na modulação do granuloma paracoccidioidomicótico. / Effect of Therapy on Paracoccidioidomicotic Granuloma Modulation.

Raphael Fagnani Sanchez Molina 07 December 2010 (has links)
A paracoccidioidomicose é uma micose sistêmica caracterizada por ser uma doença granulomatosa. As formas benignas da doença são caracterizadas por uma infecção localizada, contendo granulomas compactos com poucos fungos; já nas formas mais graves, ocorre um processo granulomatoso frouxo com focos de necrose e intensa disseminação fúngica. Objetivou-se avaliar o desenvolvimento de lesões granulomatosas em baço, fígado, pulmão e epiplon de camundongos, após infecção pela via intraperitoneal com o isolado de alta virulência, Pb18, em diferentes períodos de infecção após tratamento com fármacos, os quais possuem mecanismo de ação relacionado com a alteração no balanço entre a síntese e degradação dos produtos do colágeno, interferindo diretamente na formação do granuloma A citocina IFN-<font face=\"Symbol\">g, o antibiótico Tetraciclina e as drogas antiinflamatórias Lumiracoxib e Celecoxib. Avaliamos a presença de alguns componentes do granuloma (colágeno, células do infiltrado inflamatório, de citocinas primordiais para sintese/degradação da MEC do granuloma, presença de P. brasiliensis). / Paracoccidioidomycosis (PCM) is a systemic mycosis that is endemic in Latin America, whose causative agent is the thermal dimorphic fungus Paracoccidioides brasiliensis (Pb). PCM is a granulomatous disease, and the formation of granulomas can be understood as a mechanism of the body to block and limit the invasiveness of the fungus or its antigenic components, once unable to lyse them. Bening forms of the disease are characterized by a localized infection, where granulomasa are compact and contain few fungi. More severe forms present loose granulomatous processes with foci of necrosis and severe fungal. Studies in which granulomatous response was developed in resistant (A/J) and susceptible (B10.A) mice to the high virulence isolate Pb18 showed the presence of different patterns of injuries related to the type of extracellular matrix (ECM) components and the different cells types in the area, suggesting a important role of these elements in the formation and constitution of the granuloma and thus the outcome of infection. In our project, we aimed to evaluate the development of granulomatous lesions in the spleen, liver, lung and omentum of mice susceptible to PCM after intraperitoneal infection with Pb18, at different periods of infection (acute and chronic) with or without treatment with drugs. These drugs have mechanisms of action closely related to the change in the balance between synthesis and degradation of collagen Thus, they interfere directly in the granuloma formation and in maintaining the viability of fungi and also with the development of fibrosis. Which is a common and devastating sequelae of numerous infections including the PCM, with the characteristic proliferation of fibroblasts and deposition of ECM. The treatments were chosen based on prior knowledge on their effects on the course of experimental murine PCM. IFN-<font face=\"Symbol\">g was chosen due to its antifibrotic effect, being an activator of macrophages in infection by P. brasiliensis and increasing the fungicidal effect of neutrophils. The antibiotic tetracycline was used because of its inhibitory effect on the synthesis of extracellular matrix, limiting antimicrobial activity and the ability of collagenase to degrade ECM. Finally, the antiinflammatory drugs Celecoxib and Lumiracoxib (inhibitors of the COX-2 enzyme) 11 were used because they cause an increase in the expression of collagen type III and type IV. We analyzed the components of the granuloma (collagen, inflammatory cells, cytokines essential for synthesis / degradation of the ECM of the granuloma, the presence of P. brasiliensis). Among the cytokines analyzed, we studied the importance of TNF-<font face=\"Symbol\">&#945 in the formation of granulomas and regulation of matrix metalloproteinases (MMP) synthesis and function. We analyzed TGF-<font face=\"Symbol\">b because it negatively modulate the secretion of nitric oxide by macrophages and promote the accumulation of ECM and is believed to be the central mediator of the process of fibrosis in several pathologies. IFN-<font face=\"Symbol\">g was studied because of its correlation to the preferential Th1 immune response in diseases and infectious processes of fungal and bacterial infections, and also because it modulates fibroblast function.
40

Comparative studies of Dothiorella on avocado

Schoeman, Margareth Vuyiswa 10 October 2005 (has links)
A market survey was conducted to determine the incidence of stem-end rot (SE) on avocado fruit obtained from the Pretoria Fresh Produce Market representing the Tzaneen production area. Dothiorella aromatica isolates collected from this survey were compared in terms of physiological characteristics i.e. growth and temperature, carbon and nitrogen utilization and pH response as well as genetic relatedness using random amplified polymorphic DNA (RAPD's). The incidence of SE was found to be as high as 31% and anthracnose 18%. Symptom development was more apparent when fruit was evaluated at the overripe than eating ripe stage. Of the 12 identified fungi isolated from SE lesions, D. aromatica was by far the most frequently isolated fungus. All D. aromatica isolates tested were found to be pathogenic using the fruit inoculation technique. Based on lesion size, isolates were separated into two groups of virulent and less virulent. Most isolates grouped within the one cluster, with only one isolate falling in the second group being less virulent. Although similar groupings were found between physiological tests, a lack of consistency as to which isolate belonged to which group was found. The optimum temperature for growth was 25°C and an initial pH of 6. The mean colony growth rate was 5 mm day-1. Isolates grew at a minimum of eight to a maximum of 27 mm within 24 hours. Isolates grew best on pectin and poorly on sorbitol when used as a carbon source. Urea supported growth best and poor growth was found on casein-amended sources. At a molecular level, the RAPD technique could be used successfully to seperate isolates into three groups based on cluster analyses. OPC02 was the most discrimatory primer and was therefore used in this study. Isolates produced DNA fragments ranging from 1500 bp to 450 bp. The results obtained from RAPDs could not be correlated with the pathogenicity and physiological tests. Future studies should focus on comparing isolates from different avocado production areas and testing different primers for the ability to distinguish between isolates of D. aromatica. / Dissertation (MInst Agrar (Plant Protection))--University of Pretoria, 2005. / Microbiology and Plant Pathology / unrestricted

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