A incidÃncia de infecÃÃes oportunistas causadas por fungos, com destaque para as leveduras do gÃnero Candida vem aumentando substancialmente. Estudos relatam que tem sido observado um notÃvel crescimento de infecÃÃes por espÃcies nÃo albicans (Candida tropicalis, Candida glabrata, Candida parapsilosis e Candida krusei). Isolados clÃnicos resistentes aos azÃlicos, em especial ao fluconazol, sÃo cada vez mais relatados. As naftoquinonas sÃo uma importante classe de molÃculas biologicamente ativas, apresentando atividades antibacteriana, antifÃngica, antiviral, anti-inflamatÃria, antipirÃtica, anticancerÃgena e tripanocida e tem sido amplamente testadas em vÃrios estudos farmacolÃgicos. Nos Ãltimos anos intensificou-se o interesse nestas substÃncias, nÃo sà devido à sua importÃncia em processos bioquÃmicos vitais, como tambÃm ao destaque cada vez maior que apresentam em variados estudos farmacolÃgicos. O presente trabalho buscou avaliar e comparar o efeito antifÃngico de naftoquinonas frente a cepas de Candida tropicalis resistentes e sensÃveis ao fluconazol, utilizando diferentes tÃcnicas tais como mÃtodos de microdiluiÃÃo em caldo, procedimentos de citometria de fluxo e ensaio do Cometa. Utilizamos sete cepas de Candida tropicalis resistentes ao fluconazol para esse estudo, as quais foram isoladas de sangue e faziam parte da colecÃÃo de leveduras do LaboratÃrio de BioprospecÃÃo Experimental em leveduras (LABEL), afiliado com a Faculdade de FarmÃcia da Universidade Federal do Cearà . Foi utilizado trÃs compostos de naftoquinonas frente à 07 cepas de Candida tropicalis e foram submetidas aos testes de Sensibilidade in vitro , onde apresentaram uma potente atividade antifÃngica. AtravÃs da Citometria de Fluxo, foi possÃvel avaliar alteraÃÃes morfolÃgicas e de integridade da membrana significativas desses compostos frentes Ãs cepas, alÃm de disfunÃÃo mitocondrial e produÃÃo de espÃcies reativas de oxigÃnio. AtravÃs do ensaio do Cometa foi possÃvel encontrar danos significativos ao DNA. Em sÃntese, os resultados sugerem que estes compostos podem ser usados como agentes antifÃngicos para o tratamento de candidemias / The incidence of opportunistic infections caused by fungi, with emphasis on Candida species has increased substantially. Studies report that there has been a notable increase of infections by non-albicans species (Candida tropicalis, Candida glabrata, Candida parapsilosis and Candida krusei). Clinical isolates resistant to azoles, particularly fluconazole, are increasingly reported. The naphthoquinones are an important class of active molecules biologically presenting antibacterial, antifungal, antiviral, antiinflammatory, antipyretic, anti-cancer and trypanocidal and has been tested extensively in several pharmacological studies. In recent years intensified the interest in in this substances, not only due to your importance in vital biochemical processes as well as the increasing emphasis that they show in various pharmacological studies. This study aimed to evaluate and compare the effect of antifungal naphthoquinones against strains of Candida tropicalis resistant and susceptible to fluconazole, using different techniques such as broth microdilution methods, procedures Flow Cytometry procedures and Comet assay. We use seven strains of Candida tropicalis resistant to fluconazole for this study, which were isolated from blood and were part of the collection of yeasts Experimental Laboratory Bioprospecting in yeast (LABEL), affiliated with the Faculty of Pharmacy, Federal University of CearÃ. We used three compounds of naphthoquinones against the seven strains of Candida tropicalis and were subjected to in vitro sensitivity tests, which showed an antifungal activity potent. Through Flow Cytometry, it was possible to assess morphological changes and membrane integrity of these compounds fronts to significant strains in addition to mitochondrial dysfunction and production of reactive oxygen species. Through the Comet assay was possible to find significant damage to DNA. In summary, the results suggest that these compounds may be used as antifungal agents for the treatment of candidemia

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Candida tropicalis à uma levedura diplÃide causadora de infecÃÃes superficiais e/ou sistÃmicas, as quais podem ser adquiridas de maneira endÃgena ou exÃgena e podem acometer diversos ÃrgÃos. No Brasil, dentre as espÃcies de Candida spp., a C.tropicalis à a segunda espÃcie mais comumente isolada e no Cearà à pouco estudada. Nos dias atuais, temos vivenciado um aumento significativo das infecÃÃes fÃngicas invasivas. PorÃm as drogas antifÃngicas disponÃveis no mercado sÃo restritas a um pequeno nÃmero quando comparadas as antibacterianas. Logo, este fato unido ao aumento da frequÃncia de resistÃncia cruzada faz necessÃria a busca por novas estratÃgias terapÃuticas. A amiodarona (AMD) à usada classicamente para tratar pacientes com arritmia. Trabalhos recentes tÃm demonstrado uma ampla atividade antifÃngica desta droga quando associado ao fluconazol (FLC). No presente estudo induzimos resistÃncia em sete cepas de Candida tropicalis e avaliamos um eventual sinergismo entre FLC e AMD. A avaliaÃÃo da interaÃÃo das drogas foi determinada atravÃs do cÃlculo da Fractionary Inhibitory Concentration (FICI) e por meio da tÃcnica de citometria de fluxo, onde tambÃm avaliamos o provÃvel mecanismo de aÃÃo desse sinergismo. Os isolados utilizados no estudo pertencem ao LaboratÃrio de BioprospecÃÃo Experimental em Leveduras (LABEL) da UFC. Para o cumprimento da metodologia, as cepas foram recuperadas do estoque e identificadas por biologia molecular. A induÃÃo foi realizada adaptando-se o protocolo de Pinto e Silva (2009). Os testes de sensibilidade foram realizados utilizando-se o teste de microdiluiÃÃo em caldo padronizado pelo CLSI, segundo o documento M27-A3. Para avaliar o sinergismo utilizou-se a tÃcnica do checkboard. Por fim, para verificar o possÃvel mecanismo de aÃÃo do sinergismo, determinamos a integridade de membrana, potencial transmembrana mitocondrial, formaÃÃo de espÃcies reativas de oxigÃnio (ROS), teste do cometa, anÃlise da oxidaÃÃo de bases purinas e caspases. As cepas de C.tropicalis apÃs ~100 dias atingiram um CIM > 64Âg/mL. Os testes de sensibilidade apresentaram CIM > 64Âg/mL tanto para o FLC como para AMD. Das cepas testadas, seis apresentaram sinergismo. O tratamento FLC+AMD alterou a integridade da membrana plasmÃtica e mitocondrial, aumentou os nÃveis de ROS intracelularmente, causou danos ao DNA e, consequentemente, conduziu morte celular por apoptose. / Candida tropicalis is a diploid yeast causing superficial infections and / or systemic, which can be acquired endogenously or exogenously and can affect several organs. In Brazil, among the species of Candida spp. The C.tropicalis is the second most common species isolated in Cearà and is rarely studied. Nowadays, we have experienced a significant increase in invasive fungal infections. But antifungal drugs on the market are restricted to a small number when compared to the antibacterial. Therefore, this fact coupled with the increased frequency of cross-resistance is necessary to search for new therapeutic strategies. Amiodarone (AMD) is traditionally used to treat patients with arrhythmia. Recent studies have shown a broad antifungal activity of this drug when combined with fluconazole (FLC). In the present study we induced resistance in seven strains of Candida tropicalis and evaluate a possible synergism between FLC and AMD. The evaluation of the interaction of the drugs was determined by calculating the Fractionary Inhibitory Concentration (FICI) and by flow cytometry, where we also evaluated the likely mechanism of action of this synergism. The isolates used in this study belong to the Laboratory of Experimental Bioprospecting in yeast (LABEL) the UFC. For the fulfillment of the methodology, the strains were recovered from stock and identified by molecular biology. The induction was carried out adapting the protocol of Pinto and Silva (2009). Sensitivity tests were performed using the broth microdilution test standardized by the CLSI, the document M27-A3. To evaluate the synergism used the technique of checkboard. Finally, to determine the possible mechanism of action of synergism, we determine the membrane integrity, mitochondrial transmembrane potential, formation of reactive oxygen species (ROS), comet assay, analysis of the oxidation of purine bases and caspases. Strains C.tropicalis after ~ 100 days reached an MIC> 64μg/mL. The sensitivity tests were MIC> 64μg/mL both the FLC as AMD. Of the strains tested, six showed synergism. The treatment changed the FLC + AMD plasma membrane integrity and mitochondrial increased levels of intracellular ROS, cause DNA damage and therefore led cell death by apoptosis.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / In recent years there has been a significant increase in the incidence of fungal infections caused by Candida species. Although C. albicans be considered the principal representing of the genus, other species have been gaining prominence. C. tropicalis, for example, has been associated with serious invasive cadidiases, being the first or second type of non-Candida albicans Candida most commonly isolated in humans with candidemia and candiduria and is frequently isolated from healthy animals and animals with candidiasis. To establish infection, C. tropicalis expresses many virulence factors such as the secretion of enzymes phospholipases and proteases, biofilm production, among others. This study aimed to evaluate the in vitro antifungal susceptibility profile and production of virulence factors in strains of C. tropicalis (n=100) isolated from several animal species. The strains were subjected to in vitro susceptibility testing by broth microdilution test, M27-A3 protocol, standardized by the Clinical and Laboratory Standards Institute against amphotericin B, itraconazole and fluconazole. We also evaluated the virulence attributes, such as proteases and phospholipases production and biofilm formation. Regarding the susceptibility of C. tropicalis strains, 38% were resistant to itraconazole, 40% were resistant to fluconazole and 34% were resistant to both azoles. None of the strains were resistant to amphotericin B. Regarding the production of proteases, 84% of the strains secreted these enzymes in the medium with pH 5.0, whereas only 40% of the strains were active at pH 3.5. Only 8% of the strains produced phospholipases. The strains showed different pattern in biofilm production, which 63,2% were strong producers, 17,6% were moderate producers, and 13,3% were weak producers. In sumary, the C. tropicalis strains isolated from animals showed high rate of resistance to azoles and expressed important virulence factors, indicating a potential threat to human and animal health. / Nos Ãltimos anos houve um aumento significativo na incidÃncia de infecÃÃes fÃngicas causadas por leveduras do gÃnero Candida. Apesar de C. albicans ser considerada a principal representante do gÃnero, outras espÃcies vÃm ganhando destaque. C. tropicalis, por exemplo, tem sido associada à cadidÃases invasivas graves, sendo a primeira ou segunda espÃcie de Candida nÃo-albicans mais comumente isolada em candidemia e candidÃria em humanos, alÃm de ser frequentemente isolada da microbiota de animais saudÃveis e com candidÃase. Para estabelecer a infecÃÃo, C. tropicalis expressa diversos fatores de virulÃncia, como a secreÃÃo de enzimas protease e fosfolipase, a produÃÃo de biofilme, dentre outros. O presente trabalho buscou avaliar o perfil de sensibilidade antifÃngica in vitro e produÃÃo de fatores de virulÃncia de cepas de C. tropicalis (n=100) isoladas de diferentes espÃcies animais. As cepas foram submetidas a teste de sensibilidade in vitro por meio do mÃtodo de microdiluiÃÃo em caldo, protocolo M27-A3, padronizado pelo Clinical and Laboratory Standards Institute, frente anfotericina B, itraconazol e fluconazol. Foram avaliados ainda os atributos de virulÃncia: produÃÃo de enzimas proteases e fosfolipases e produÃÃo de biofilme. Quanto ao perfil de sensibilidade das cepas de C. tropicalis, 38% foram resistentes a itraconazol, 40% resistentes a fluconazol e 34% foram resistentes a ambos os derivados azÃlicos. Nenhuma cepa apresentou resistÃncia a anfotericina B. Quanto a produÃÃo de proteases, 84% das cepas secretaram estas enzimas em meio com pH 5,0, enquanto somente 40% das cepas foram ativas em pH 3,5. Somente 8% das cepas produziram fosfolipases. As cepas apresentaram padrÃo diferenciado na produÃÃo de biofilme, em que 63,2% foram consideradas fortes produtoras, 17,6% foram consideradas moderadas produtoras e 13,3% foram consideradas fracas produtoras. Em suma, os isolados de C. tropicalis provenientes de animais apresentaram resistÃncia a derivados azÃlicos e expressaram fatores de virulÃncia importantes, indicando potencial risco à saÃde humana e animal.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2018-03-14T12:40:00Z No. of bitstreams: 1 Darne Germano de Almeida.pdf: 17175209 bytes, checksum: cdf4af80710a872ffc91bc54a2b03ec3 (MD5) / Made available in DSpace on 2018-03-14T12:40:00Z (GMT). No. of bitstreams: 1 Darne Germano de Almeida.pdf: 17175209 bytes, checksum: cdf4af80710a872ffc91bc54a2b03ec3 (MD5) Previous issue date: 2017-02-22 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Financiadora de Estudos e Projetos - Finep / Contamination by petroleum and its by-products causes serious damage, which has awakened great attention to the development and application of innovative technologies for the removal of these contaminants. In this sense, this work aimed to produce a biosurfactant of Candida tropicalis UCP0996 from industrial residues as substrates for application as a remediation agent. Biosurfactant production optimization was evaluated for the influence of the variables concentrations of molasses, corn steep liquor, residual canola oil and inoculum size on the response variables of surface tension and biosurfactant yield. The optimum conditions selected for the fermentative process were 2.5% of residual canola oil, 2.5% of corn steep liquor, 2.5% of molasses and 2% of inoculum size, with reduction of surface tension and yield of 29.98 mN/m and 4.19 g/L, respectively. The biosurfactant was produced in bioreactors, yielding yields of 5.87 g/L (2 L bioreactor) and 7.36 g/L (50 L bioreactor). The tensioactive and emulsifying capacity of the biosurfactant was investigated under extreme conditions of temperature, salinity, pH and heating time, indicating their stability. Chemical composition investigation of the by Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H NMR) and gas chromatography coupled to mass spectrometry (GC-MS) revealed that the biosurfactant studied is an anionic glycolipid with critical micelle concentration (CMC) of 600 mg/L and low hydrophobicity. After the characterization, the biomolecule had its toxicity investigated against the microcrustacean Artemia salina, proving to be innocuous against this environmental indicator. The biosurfactant was then subjected to different methodologies for the formulation of a commercial additive. The biomolecule remained stable for 120 days at room temperature after addition of potassium sorbate as a preservative. The application of the biomolecule in petroderivative removal and degradation processes demonstrated its ability to disperse about 71% of the motor oil into seawater, to remove 67% of the oil adsorbed on a porous surface and to increase the degradation of the oil by microorganisms. Based on the results, it was possible to establish the biotechnological potential of the product obtained for application in the industrial and environmental area, replacing the synthetic surfactants. / A contaminação por petróleo e seus derivados causam prejuízos graves, o que tem despertado grande atenção para o desenvolvimento e aplicação de tecnologias inovadoras para a remoção desses contaminantes. Nesse sentido, este trabalho teve por objetivo produzir um biossurfactante de Candida tropicalis UCP0996 a partir de resíduos industriais como substratos para aplicação como agente de remediação. A otimização da produção do biossurfactante foi avaliada quanto à influência das variáveis concentrações de melaço, milhocina, óleo de canola residual e tamanho do inóculo sobre as variáveis resposta tensão superficial e rendimento em biossurfactante. As condições ótimas selecionadas para o processo fermentativo foram 2,5% de óleo de canola residual, 2,5% de milhocina, 2,5% de melaço e tamanho do inóculo de 2%, com redução da tensão superficial e rendimento de 29,98 mN/m e 4,19 g/L, respectivamente. O biossurfactante foi produzido em biorreatores, alcançando rendimentos de 5,87 g/L (biorreator de 2 L) e 7,36 g/L (biorreator de 50 L). A capacidade tensoativa e emulsificante do biossurfactante foi investigada sob condições extremas de temperatura, salinidade, pH e tempo de aquecimento, indicando sua estabilidade. A investigação da composição química por espectroscopia no infravermelho por transformada de Fourier (FTIR), ressonância magnética nuclear de prótons (1H RMN) e cromatografia gasosa e acoplada a espectroscopia de massa (GC-MS) revelou que o biossurfactante estudado é um glicolipídeo de natureza aniônica com concentração micelar crítica (CMC) de 600 mg/L e de baixa hidrofobicidade. Após a caracterização, a biomolécula teve sua toxicidade investigada frente ao microcrustáceo Artemia salina, demonstrando ser inócua frente a este indicador ambiental. Em seguida, o biossurfactante foi submetido a diferentes metodologias para ser formulado como aditivo comercial. A biomolécula manteve-se estável ao longo de 120 dias à temperatura ambiente após adição de sorbato de potássio como conservante. A aplicação da biomolécula em processos de remoção e degradação de petroderivado demonstrou sua capacidade de dispersar cerca de 71% do óleo de motor em água do mar, de remover 67% do óleo adsorvido em superfície porosa e de aumentar a degradação do óleo pelos micro-organismos marinhos autóctones. Com base nos resultados, foi possível estabelecer o potencial biotecnológico do produto obtido para aplicação na área industrial e ambiental, em substituição aos surfactantes sintéticos.

Cardiac failure is one of the leading cause of deaths worldwide. Potential therapeutic approach, which overcome invasive organ transplantation and delivery of immunosuppressive drugs, is lacking nowadays. However, research of mesenchymal stem cells (MSCs) therapy displays immunomodulation potential, which can further promote variety of organ regeneration without need of drug treatment. Xenopus tropicalis immature Sertoli cells (XtiSCs) culture was established in our laboratory from juvenile Xenopus tropicalis male. XtiSCs possess immunomodulatory capacity and differentiation to cardiomyocytes after the treatment with the inhibitor of glycogen synthase kinase-3 (GSK-3) CHIR99021. To test the survival rate of transplanted XtiSCs we firstly microinjected treated cells directly inside tadpole's heart. XtiSCs proliferated there for the whole tested time period (30 days). However, after direct heart XtiSCs injection and subsequent cardiac injury in adult frog, no cells were localized in wound area. Thus, we focused on remote control of cardiac regeneration using XtiSCs without CHIR99021 treatment. We injected cells inside skeletal muscle bed and confirmed their survival and proliferation. Moreover, if cells were transplanted 3 days before heart injury, it resulted in significant reduction of fibronectin...

Thanks to their ability to differentiate into variable cell types and migrate to the site of an injury mesenchymal stem cells (MSC) are broadly used in regenerative medicine. Their relative easy availability together with the property to control the immune system determines them as a cure of autoimmune diseases or a recovery of wounded tissues. Similar features posses Sertoli cells which take place in the seminiferous tubule of testis. Cell culture of testicular stem cells from juvenile male testes of X. tropicalis (XtTSC) was established in supervisor's laboratory. This cell culture showing both MSC's and SeC's properties was transformed to carry red fluorescent protein RFP. The aim of this diploma thesis was to investigate an behavior of transformed XtTSC in living organism, therefore cells were transplanted into the X. tropicalis tadpoles in stage 41. Subsequently, their migration potential was explored. To study of XtTSC's differentiation potential it was necessary to introduce a reliable sectioning techniques for the subsequent immunohistochemical analysis. Based on our experiments, we found that the XtTSC's cell culture contains precursors of SeC and peri-tubular myoid cells, however in vivo these cells turned into the dedifferentiated MSC-like state allowing a strong migration through the...

Invasive fungal infections are a significant clinical challenge especially for hospitalized patients as traditional antifungal therapy often fails to resolve these infections. The ability of Candida to undergo yeast-to-hyphae morphological transition is central to this invasive behavior. Morphogenesis is also important for the formation of biofilms which are highly structured communities of microorganisms attached to one another or substratum and embedded within a protective extracellular matrix material. The refractory nature of cells within a biofilm to current antifungal therapies has created a need for alternative antifungal agents for the management of Candida biofilm-related infections. The novel antifungal occidiofungin is a natural product produced by the soil bacteria Burkholderia contaminans shown to be effective against a broad range of fungi including Candida spp. Prior studies have demonstrated that occidiofungin inhibits yeast-to-hyphae morphogenesis in the dimorphic yeast, C. albicans, likely through its impact on disrupting F-actin organization. To extend these findings, the efficacy of occidiofungin on morphogenesis of C. albicans and C. tropicalis strains under different inducing conditions was evaluated. Further, given the role of biofilm on pathogenicity, the anti-biofilm properties of occidiofungin against Candida species was examined using an in vitro static biofilm model developed on a silicon elastomer disk. The accumulated data indicate that occidiofungin inhibits hyphal transformation regardless of the inducing conditions used and prevents hyphal extension when added to cells post switching. Moreover, morphologically switching cells were more sensitive to occidiofungin than their yeast counterpart. In addition, occidiofungin effectively blocks biofilm formation at all stages of development and reduces dispersed cells from the biofilm for both C. albicans and C. tropicalis. Confocal data revealed alterations in actin organization with occidiofungin treatment for both morphologically switching and biofilm cells. These findings correlate with prior observations for occidiofungin activity on yeast form cells indicating the broad activity of occidiofungin against fungi at various stages of pathogenic growth and supports efforts to pursue occidiofungin as a potential therapeutic against Candida based infections.

Seventeen species of facultative anaerobic bacteria belonging to three genera (Serratia, Cellulomonas, and Corynebacterium) were screened for the production of xylitol; a sugar alcohol used as a sweetener in the pharmaceutical and food industries. A chromogenic assay of both solid and liquid cultures showed that 10 of the 17 species screened could grow on D-xylose and produce detectable quantities of xylitol during 24-96 h of fermentation. The ten bacterial species were studied for the effect of environmental factors, such as temperature, concentration of D-xylose, and aeration, on xylitol production. Under most conditions, Corynebacterium sp. NRRL B 4247 produced the highest amount of xylitol. The xylitol produced by Corynebacterium sp. NRRL B 4247 was confirmed by mass spectrometry. Corynebacterium sp. NRRL B 4247 was studied for the effect of initial D-xylose concentration, glucose, glyceraldehyde, and gluconate, aeration, and growth medium. Corynebacterium sp. NRRL B 4247 produced xylitol only in the presence of xylose, and did not produce xylitol when gluconate or glucose was the substrate. The highest yield of xylitol produced in 24 h (0.57 g/g xylose) was using an initial D-xylose concentration of 75 g/l. Under aerobic conditions the highest xylitol yield was 0.55 g/g while under anaerobic conditions the highest yield was 0.2 g/g. Glyceraldehyde in concentrations greater than 1 g/l inhibited Corynebacterium sp. B 4247 growth and xylitol production. Corynebacterium sp. NRRL B 4247 culture grown in the presence of potassium gluconate (96 g/l) for 48 h and on addition of D-xylose to the media increased accumulation to 10.1 g/l of xylitol after 150 h. Corynebacterium sp. NRRL B 4247 exhibited both NADH and NADPH-dependent xylose reductase activity in cell-free extracts. The NADPH-dependent activity was substrate dependent. The activity was 2.2-fold higher when DL-glyceraldehyde was used as substrate than with D-xylose. In cell-free extracts the difference in xylose reductase and xylitol dehydrogenase activity was highest at 24 h, whereas for cell cultures that were grown in gluconate and xylose, the difference in the reductase and dehydrogenase activities was highest at 12 h after xylose addition. The NAD+ dependent xylitol dehydrogenase activity was low compared to the cells grown without gluconate. The molecular weight of NADPH-dependent xylose reductase protein obtained by gel filtration chromatography was 58 kDa. Initial purification was performed on a DE-52 anion exchange column. Purification using Red Sepharose affinity column resulted in a 58 kDa protein on the SDS PAGE gel and was further purified on a Mono-Q column. The activity stained band on the native gel yielded 58, 49, 39 and 30 kDa bands on the denaturing gel. The peptides of the 58 kDa protein of Corynebacterium sp. B 4247 sequenced by mass spectrometry, identified with E2 and E3 (Bacillus subtilis) components of multi-enzyme system consisting of pyruvate dehydrogenase complex, 2-oxoglutarate dehydrogenase complex and oxo-acid dehydrogenase complex. A 75% match was shown by the peptide "QMSSLVTR" with E-value of 8e-04 to the Saccharomyces cerevisiae protein that was capable of reducing xylose to xylitol. The peptide "LLNDPQLILMEA" had conserved match "LL + DP" over several aldose reductases. The xylose reductase of the yeast Candida tropicalis ATCC 96745 was also purified. The molecular weight of the yeast NADPH-dependent xylose reductase was about 37 kDa on an SDS PAGE / Ph. D.

A administração de Ags solúveis via mucosas, antes da sensibilização com o mesmo Ag, leva a tolerância. Na presente tese estudou-se o efeito do LPS i.n. durante a indução de tolerância nasal a ovalbumina (OVA). A maioria dos modelos murinos de asma utilizam a OVA como alérgeno, desse modo também utilizamos o extrato de Blomia tropicalis (Bt), um ácaro prevalente em pacientes asmáticos. Características da Bt impedem o estabelecimento de tolerância e evidências experimentais indicam que a tolerância a um Ag pode induzir tolerância a um Ag não relacionado (tolerância cruzada). Assim, avaliamos se a tolerância a OVA ou lizozima de ovo (HEL) poderia induzir tolerância cruzada a Bt. Observou-se que o LPS i.n. durante a indução de tolerância a OVA previne o estabelecimento da tolerância, resultando em neutrofilia pumonar, IgG2a, diminuição de IgE com aumento de IgG1 anafilática. Observou-se também que a tolerância nasal, a HEL ou OVA, não é eficaz em induzir tolerância cruzada para as respostas contra Bt. Já, a tolerância oral com OVA induziu tolerância cruzada para Bt. / Mucosal administration of soluble Ags, before the sensitization with the same Ag, leads to mucosal tolerance. We studied the effect of i.n. LPS during the induction of ovalbumin (OVA) nasal tolerance. The majority of murine models of asthma used OVA as allergen,thus, we also used Blomia tropicalis (Bt) extract, a mite more common in asthmatic patients. Features of Bt block the nasal tolerance establishment and experimental data indicates that tolerance towards an Ag can promote tolerance to another not related Ag (cross-tolerance). Therefore, we evaluated if OVA or hen-egg white lisozyme (HEL) tolerance could result in cross-tolerance to the Bt. Our data showed that i.n. LPS during induction of tolerance to OVA prevents the establishment of this tolerance, resulting in neutrophil migration, IgG2a production, decreased levels of IgE and increased anaphylactic IgG1. We verify that nasal tolerance to HEL or OVA is not capable in induce cross-tolerance against the Bt. We also observed that OVA oral tolerance is able to induce cross-tolerance against Bt.

Em contraste com a vasta descrição na literatura científica dos biofilmes bacterianos, poucos trabalhos focam o estudo da formação e as estratégias de inibição da constituição do biofilme fúngico. Este trabalho objetiva a caracterização do potencial antifúngico e antibiofilme do sal imidazólico 1-metil-3-octilimidazol cloreto (C16MImCl), e das frações (F70 e F90) purificadas de saponinas mate (Ilex paraguariensis A. st. Hil.), frente a células de biofilme de seis isolados clínicos de Candida tropicalis. A Concentração Inibitória Mínima (CIM) do C16MImCl foi de 0,014μg/mL frente às células planctônicas, ao passo que as Frações de Saponinas da Erva Mate (FSEM) não apresentaram atividade antifúngica. Utilizando o cateter traqueal (CT) como corpo de prova, foi utilizado para avaliar a capacidade de inibição e remoção do biofilme. Avaliou-se também a Concentração Mínima de Erradicação do Biofilme (CMEB) para remoção do biofilme pré-formado pelo método da microplaca. Para a atividade antibiofilme foi observado que o C16MImCl, apresentou melhor resultado quando comparado ao fluconazol. As FSEM também apresentaram atividade antibiofilme quando comparados ao fluconazol, entretanto menores do que o tensoativo sintético Pela análise dos resultados de CMEB, o C16MImCl foi o composto com maior capacidade de erradicar o biofilme pré-formado, na concentração de 0,9 μg/mL (92% a 100% de remoção do biofilme). Os demais compostos testados (fluconazol, FEM e a água) não apresentaram atividade removedora, observando-se valores menores que 80% de remoção. Tanto as concentrações nas quais C16MImCl inibiu as células planctônicas (0,014 μg/mL) como as de biofilme (0,028 -0,225 μg/mL) foram mais baixas que as obtidas pelo fluconazol. Os resultados obtidos demonstram a potencialidade destes tensoativos, principalmente o C16MImCl, que demonstrou baixa toxicidade e provável mecanismo de ação sobre a síntese do ergosterol. Assim, é possível afirmarmos que estes tensoativos representam uma potencial alternativa para o controle químico de fungos leveduriformes, especialmente as ocasionadas por células de biofilme por C. tropicalis. / In contrast to the extensive description in the literature of bacterial biofilms, few works focus on the study of the formation and strategies for inhibiting the formation of fungal biofilms. This work aims to characterize the antifungal potential and antibiofilm the imidazole salt 1 - methyl - 3 - octilimidazol chloride (C16MImCl), and fractions (F70 and F90) purified saponins mate (Ilex paraguariensis A. st. Hil.), against to biofilm cells of six clinical isolates of Candida tropicalis. The Minimum Inhibitory Concentration (MIC) of C16MImCl was 0.014 mg / mL to planktonic cells, whereas the Saponin Fractions of Yerba Mate (SFYM) showed no antifungal activity. Using the tracheal catheter (CT) as a specimen was used to evaluate the ability of the biofilm inhibition and removal. We also assessed the Minimum Biofilm Eradication Concentration (MBEC) to remove the preformed biofilms by the microplate method. For antibiofilm activity was observed that C16MImCl, showed better results when compared to fluconazole. The SFYM also had antibiofilm activity when compared to fluconazole, however smaller than the synthetic surfactant. By analyzing the results MBEC, the compound C16MImCl was capacity to eradicate pre- formed biofilm in a concentration of 0.9 mg / mL (92% to 100% biofilm removal) The other tested compounds (fluconazole, SFYM and water) showed no activity remover, observing less than 80 % removal values. Both concentrations at which they inhibit planktonic cells C16MImCl (0.014 μg/mL) and the biofilm (0.028 -0.225 μg/ml) were lower than those obtained by fluconazole. The results obtained demonstrate the potential of these surfactants, especially C16MImCl, which demonstrated low toxicity and probable mechanism of action on the synthesis of ergosterol. Thus, it is possible to assert that these surfactants are a potential alternative to chemical control of yeasts, especially those caused by biofilm cells of C. tropicalis.