A Criptococose é uma enfermidade micótica sistêmica, subaguda ou crônica, que acomete a cavidade nasal, tecidos paranasais e pulmões do homem, animais domésticos e silvestres, podendo disseminar-se para o sistema nervoso central, olhos, pele e outros órgãos. Considerando as dificuldades terapêuticas no tratamento da micose em pequenos animais, incluindo toxicidade, desenvolvimento de resistência aos antifúngicos tradicionalmente utilizados e longos períodos de tratamento da enfermidade, o estudo objetivou avaliar a eficácia do imunomodulador ß (1-3) glucana isoladamente e em associação ao fluconazol no tratamento da criptococose experimental. Foram utilizados 100 camundongos (Mus musculus), cepa UFPel, albinos, os quais foram divididos em cinco grupos de 20 animais. O tratamento dos animais com criptococose experimental foi iniciado sete dias após a inoculação. O grupo Controle (G1) foi tratado com 0,1 ml de água destilada estéril, o grupo Fluconazol (G2) com 5 mg/kg de fluconazol, o grupo Fluconazol associado a ß (1-3) glucana (G3) com 5 mg/kg de fluconazol associado a 0,5 mg de ß (1-3) glucana, o grupo Glucana dose I (G4) com 0,5 mg de ß (1-3) glucana e o grupo Glucana dose II (G5) recebeu 0,25 mg de ß (1-3) glucana. Após acompanhamento clínico durante as seis semanas de tratamento os animais foram eutanasiados e necropsiados para avaliação anatomopatológica dos órgãos, quantificação das unidades formadoras de colônias fúngicas (UFCs), retroisolamento e avaliação histopatológica. Nas avaliações clínicas o G3 foi sempre superior ao G1 e G2, sendo que na última avaliação clínica individual, os animais pertencentes ao G3 não apresentavam nenhum sintoma clínico. O G2 teve um menor número de órgãos afetados e de alterações macroscópicas, seguido pelo G3, sendo que no primeiro não foram observadas lesões em órgãos-alvo, como pulmão e cérebro. O grupo com maior número de lesões e órgãos afetados foi o G1. Nos parâmetros retroisolamento e UFCs, o G3 foi superior aos outros tratamentos, seguido pelo G2, sendo que o pior grupo, ou seja, aquele que teve um maior número de isolamentos e maior quantificação de UFCs foi o G1. Conforme os resultados obtidos os tratamentos G2 e G3 foram os mais eficazes para a remissão da criptococose experimental, no entanto, G3 apresentou uma superioridade na maioria dos parâmetros avaliados. Portanto, de acordo com os resultados obtidos, a associação de fluconazol ao imunomodulador ß (1-3) glucana pode ser uma alternativa benéfica em considerável quantidade de pacientes com criptococose. / Cryptococcosis is a systematic sub acute or chronic mycotic condition that affects the nasal cavity, paranasal tissues and the lungs of humans, as well as domestic and wild animals, which can spread to the central nervous system, skin, and other organs. Considering the therapeutic difficulties in treating this mycosis in small animals, which include toxicity, resistance towards traditionally used antifungals, and the extended treatment of this condition, this study aimed to evaluate the ß (1-3) glucan immunomodulator efficacy when used both alone and in association with fluconazole in the treatment of experimental cryptococcosis. One Hundred albino UFPel strain mice (Mus musculus), divided into five groups of 20 animals each, were used. The treatment of these animals with experimental cryptococcosis was started seven days following inoculation. The control group (G1) was treated with 0,1 ml sterile distilled water. The fluconazole group (G2) was treated with 5 mg/kg fluconazole; the fluconazole associated with ß glucan (1-3) group (G3) was treated with 5 mg/kg fluconazole associated with 0,5 mg ß (1-3) glucan ; the group glucan dose I (G4) was treated with 0,5 mg ß (1-3) glucan, and the group glucan dose II (G5) was administered 0,25 mg ß (1-3) glucan. After the six-week treatment clinical follow-up, the aimals were euthanized and necropsied for anatomopathological evaluation of organs, quantification of fungal colony-forming units (FCUs), retro isolation and histopathological evaluation. In clinical evaluations, G3 was always superior to G1 and G2, and in the last individual clinical evaluation, G3 animals did not show any clinical symptoms. G2 had a smaller number of affected organs and microscopic alterations, followed by G3. In G2, target organ lesions, such as those in the lungs and brain, were not found. Considering retro isolation and FCU parameters, G3 was superior to other treatments, followed by G2; the worst group, that is, the one with the highest isolation occurrence and greatest FCU quantification, was G1. According to the results obtained, treatments G2 and G3 were the most efficient in experimental cryptococcosis remission; however, G3 was superior in most parameters evaluated. Therefore, according to the results obtained, the association of fluconazole with the ß (1-3) glucan immunomodulator can be a beneficial alternative to a considerable number of cryptococcosis-bearing patients.

Orientador: Virgínia Bodelão Richini-Pereira / Resumo: A emergência e reemergência de doenças infecciosas é impulsionada por vários fatores e a busca de patógenos em amostras animais podem oferecer oportunidades para estudos eco-epidemiológicos e também dados sobre a evolução dos patógenos. O objetivo deste estudo foi avaliar a ocorrência de fungos patogênicos importantes em saúde pública, em exemplares de animais silvestres mortos por atropelamento no estado de Santa Catarina e identificar e mapear áreas de risco para a infecção humana. Grande parte destes fungos apresenta em comum dimorfismo, distribuição geográfica restrita e produção de conídios infectantes que são aspirados pelo hospedeiro por meio das vias respiratórias. Cães e tatus são apontados como transmissores de Paracoccidioides brasiliensis, os morcegos ao Histoplasma spp., assim como as fezes de pombos ao Cryptococcus spp.. No presente trabalho foram analisadas 1063 amostras de pulmão, fígado, baço, pele e coração de 297 animais silvestres, para detecção de Paracoccidioides brasiliensis, Histoplasma capsulatum e Cryptococcus spp. pela técnica de Reação em Cadeia de Polimerase (PCR). Utilizou-se primers universais para detecção de fungos em geral e obteve-se positividade em 102 amostras de 59 animais. Para a análise de P. brasiliensis, utilizou-se os primers específicos, obtendo oito amostras positivas em cinco animais (quatro Oxymycterus spp. e um Euryoryzomys russatus). Não houve a detecção molecular para Histoplasma spp.. Foi possível a identificação de três amos... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

A Criptococose é uma enfermidade micótica sistêmica, subaguda ou crônica, que acomete a cavidade nasal, tecidos paranasais e pulmões do homem, animais domésticos e silvestres, podendo disseminar-se para o sistema nervoso central, olhos, pele e outros órgãos. Considerando as dificuldades terapêuticas no tratamento da micose em pequenos animais, incluindo toxicidade, desenvolvimento de resistência aos antifúngicos tradicionalmente utilizados e longos períodos de tratamento da enfermidade, o estudo objetivou avaliar a eficácia do imunomodulador ß (1-3) glucana isoladamente e em associação ao fluconazol no tratamento da criptococose experimental. Foram utilizados 100 camundongos (Mus musculus), cepa UFPel, albinos, os quais foram divididos em cinco grupos de 20 animais. O tratamento dos animais com criptococose experimental foi iniciado sete dias após a inoculação. O grupo Controle (G1) foi tratado com 0,1 ml de água destilada estéril, o grupo Fluconazol (G2) com 5 mg/kg de fluconazol, o grupo Fluconazol associado a ß (1-3) glucana (G3) com 5 mg/kg de fluconazol associado a 0,5 mg de ß (1-3) glucana, o grupo Glucana dose I (G4) com 0,5 mg de ß (1-3) glucana e o grupo Glucana dose II (G5) recebeu 0,25 mg de ß (1-3) glucana. Após acompanhamento clínico durante as seis semanas de tratamento os animais foram eutanasiados e necropsiados para avaliação anatomopatológica dos órgãos, quantificação das unidades formadoras de colônias fúngicas (UFCs), retroisolamento e avaliação histopatológica. Nas avaliações clínicas o G3 foi sempre superior ao G1 e G2, sendo que na última avaliação clínica individual, os animais pertencentes ao G3 não apresentavam nenhum sintoma clínico. O G2 teve um menor número de órgãos afetados e de alterações macroscópicas, seguido pelo G3, sendo que no primeiro não foram observadas lesões em órgãos-alvo, como pulmão e cérebro. O grupo com maior número de lesões e órgãos afetados foi o G1. Nos parâmetros retroisolamento e UFCs, o G3 foi superior aos outros tratamentos, seguido pelo G2, sendo que o pior grupo, ou seja, aquele que teve um maior número de isolamentos e maior quantificação de UFCs foi o G1. Conforme os resultados obtidos os tratamentos G2 e G3 foram os mais eficazes para a remissão da criptococose experimental, no entanto, G3 apresentou uma superioridade na maioria dos parâmetros avaliados. Portanto, de acordo com os resultados obtidos, a associação de fluconazol ao imunomodulador ß (1-3) glucana pode ser uma alternativa benéfica em considerável quantidade de pacientes com criptococose. / Cryptococcosis is a systematic sub acute or chronic mycotic condition that affects the nasal cavity, paranasal tissues and the lungs of humans, as well as domestic and wild animals, which can spread to the central nervous system, skin, and other organs. Considering the therapeutic difficulties in treating this mycosis in small animals, which include toxicity, resistance towards traditionally used antifungals, and the extended treatment of this condition, this study aimed to evaluate the ß (1-3) glucan immunomodulator efficacy when used both alone and in association with fluconazole in the treatment of experimental cryptococcosis. One Hundred albino UFPel strain mice (Mus musculus), divided into five groups of 20 animals each, were used. The treatment of these animals with experimental cryptococcosis was started seven days following inoculation. The control group (G1) was treated with 0,1 ml sterile distilled water. The fluconazole group (G2) was treated with 5 mg/kg fluconazole; the fluconazole associated with ß glucan (1-3) group (G3) was treated with 5 mg/kg fluconazole associated with 0,5 mg ß (1-3) glucan ; the group glucan dose I (G4) was treated with 0,5 mg ß (1-3) glucan, and the group glucan dose II (G5) was administered 0,25 mg ß (1-3) glucan. After the six-week treatment clinical follow-up, the aimals were euthanized and necropsied for anatomopathological evaluation of organs, quantification of fungal colony-forming units (FCUs), retro isolation and histopathological evaluation. In clinical evaluations, G3 was always superior to G1 and G2, and in the last individual clinical evaluation, G3 animals did not show any clinical symptoms. G2 had a smaller number of affected organs and microscopic alterations, followed by G3. In G2, target organ lesions, such as those in the lungs and brain, were not found. Considering retro isolation and FCU parameters, G3 was superior to other treatments, followed by G2; the worst group, that is, the one with the highest isolation occurrence and greatest FCU quantification, was G1. According to the results obtained, treatments G2 and G3 were the most efficient in experimental cryptococcosis remission; however, G3 was superior in most parameters evaluated. Therefore, according to the results obtained, the association of fluconazole with the ß (1-3) glucan immunomodulator can be a beneficial alternative to a considerable number of cryptococcosis-bearing patients.

Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2017-12-26T16:15:27Z No. of bitstreams: 2 Dissertação - Lucas Daniel Quinteiro de Oliveira 2017.pdf: 3361217 bytes, checksum: f1ea8dda888ba50d64581258f8ca97cd (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Rejected by Luciana Ferreira (lucgeral@gmail.com), reason: Olha a unidade acadêmica é IPTSP e não FM on 2017-12-27T10:44:54Z (GMT) / Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2017-12-27T12:11:57Z No. of bitstreams: 2 Dissertação - Lucas Daniel Quinteiro de Oliveira 2017.pdf: 3361217 bytes, checksum: f1ea8dda888ba50d64581258f8ca97cd (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-12-28T09:29:42Z (GMT) No. of bitstreams: 2 Dissertação - Lucas Daniel Quinteiro de Oliveira 2017.pdf: 3361217 bytes, checksum: f1ea8dda888ba50d64581258f8ca97cd (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-12-28T09:29:42Z (GMT). No. of bitstreams: 2 Dissertação - Lucas Daniel Quinteiro de Oliveira 2017.pdf: 3361217 bytes, checksum: f1ea8dda888ba50d64581258f8ca97cd (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-10-26 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The Cryptococcus neoformans complex comprises two species responsible for causing cryptococcosis, the main manifestation being meningoencephalitis in immunocompromised hosts. Its pathogenicity is related to virulence factors. The treatment of this disease is difficult because the drugs present high toxicity, resistance of the fungus and little therapeutic efficiency. Research with biologically active natural products has shown that essential oils (OEs) have important antifungal activity. Thus, the present study had as objective to evaluate the antifungal efficacy and action on the virulence factors in C. neoformans complexes of OEs of Cinamomum cassia (Cinnamon of China) and Cybopogom flexuosus (Lemon Grass). By means of the microdilution technique in broth, OEs had MIC ranging from 8 to 256 μg / ml and CFM from 16 to 512 μg / ml. C. cassia promoted a 47.8% reduction in capsule size and inhibited melanin synthesis in 30% of the isolates. The evaluation of this OE on the activity of exoenzymes phospholipase, urease and DNAse demonstrated inhibition in 15%, 30% and 25% of the evaluated isolates respectively. C. flexuosus reduced the size of the capsule by 48.7%, inhibited the production of melanin, urease, phospholipase and DNAse by 30%, 30%, 25% and 15% respectively. The data demonstrated that the isolates did not produce proteinase and the hemolytic activity was reduced by 15% for C. cassia and 45% C. flexuous. The results highlight the potential of these OEs in the treatment of cryptococcosis as well as the inhibition of virulence factors. These data are promising, and further research is needed to develop of a new drug. / O complexo Cryptococcus neoformans compreende duas espécies, responsáveis por causar criptococose, sendo a principal manifestação a meningoencefalite em imunocomprometidos. Sua patogenicidade está relacionada aos fatores de virulência. O tratamento desta enfermidade é dificultado devido aos fármacos apresentarem alta toxicidade, resistência do fungo e pouca eficiência terapêutica. Pesquisa com produtos naturais biologicamente ativos tem demonstrado que os óleos essenciais (OEs) apresentam importante atividade antifúngica. Assim, o presente estudo teve como objetivo avaliar a eficácia como antifúngico e ação sobre os fatores de virulência em espécies do complexo C. neoformans dos OEs de Cinamomum cassia (Canela da China) e Cybopogom flexuosus (Capim limão). Por meio da técnica de microdiluição em caldo, os OEs apresentaram CIM variando entre 8 a 256 μg/ml e CFM de 16 a 512 μg/ml. C. cassia promoveu uma redução de 47,8% no tamanho da cápsula e inibiu a síntese de melanina em 30% dos isolados. A avaliação deste OE sobre da atividade das exoenzimas fosfolipase, urease e DNAse demonstrou inibição em 15%, 30% e 25% dos isolados avaliados respectivamente. C. flexuosus reduziu o tamanho da cápsula em 48,7%, inibiu a produção de melanina, urease, fosfolipase e DNAse em 30%, 30%, 25% e 15% respectivamente. Os dados demonstraram que os isolados não produziram proteinase e a atividade hemolítica foi reduzida em 15% para C. cassia e 45% C. flexuosos. Os resultados enaltecem o potencial desses OEs no tratamento da criptococose assim como na inibição dos fatores de virulência. Esses dados são promissores, sendo necessário pesquisas mais aprofundadas para o desenvolvimento de um novo fármaco.

Orientadores: Francisco Maugeri Filho, Gonçalo Amarante Guimarães Pereira / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-25T00:15:25Z (GMT). No. of bitstreams: 1 Andrade_CristianeContePaimde_D.pdf: 8118229 bytes, checksum: e37327c8c0a8a32ecfc89552e46cbd0d (MD5) Previous issue date: 2014 / Resumo: Xilanases são enzimas que hidrolisam as ligações glicosídicas entre as unidades de xilose que compõem a xilana, o principal constituinte hemicelulósico. Devido à grande disponibilidade desse tipo de material na natureza, as xilanases podem ser empregadas em diversos ramos, como nas indústrias têxtil, de alimentos e de rações, na bioconversão de resíduos lignocelulósicos, no clareamento de papel e polpa, e no tratamento de resíduos. Visando descrever novas enzimas para futuras aplicações, este trabalho teve como objetivo purificar e caracterizar a xilanase produzida pelo basidiomiceto Cryptococcus sp. LEB-AY10, uma levedura previamente isolada da Mata Atlântica e selecionada pela produção de enzima termoestável. Para tanto, o micro-organismo foi inicialmente identificado em nível de espécie e depositado como C. flavescens LEB-AY10 (CCT 7725); em sequência, foi estudada a produção da enzima utilizando, como substrato, bagaço de cana-de-açúcar, pré-tratado por explosão a vapor em três diferentes condições, bem como suas respectivas frações solúveis, e suplementados com melaço ou componentes sintéticos. Tendo sido definida a metodologia de tratamento do bagaço, técnicas de planejamento experimental foram utilizadas para estudar a influência das variáveis de cultivo e aumentar a atividade da xilanase produzida. Nas condições otimizadas, obteve-se aumento de 5,6 vezes na atividade em relação aos testes iniciais, atingindo 4,67 U/mL (a 50°C) ou 8,33 U/mL (a 80°C) em 96 h de incubação. Posteriormente, realizou-se a purificação da xilanase em duas etapas cromatográficas (troca iônica e permeação em gel), sendo possível recuperar 45% da atividade inicial. A massa molecular média foi estimada em 48 kDa. A enzima apresentou atividade ótima a 77,5°C e maior estabilidade em pH próximo a 5,3. Neste pH, as meias-vidas desta enzima foram estimadas em 9,2 minutos a 77,5°C e 33,74 h a 67°C. Os parâmetros cinéticos Km e vmax utilizando xilana de bétula (birchwood) como substrato foram 4,13 g/L e 2,32 U/mL, respectivamente. A xilanase purificada apresentou baixas atividades de ?-xilosidase em 4-nitrofenil-?-D-xilopiranosídeo (0,02 U/mg) e de celulase em carboximetilcelulose (0,99 U/mg). Os produtos de hidrólise da xilana de faia (beechwood) pela xilanase de C. flavescens LEB-AY10 foram, principalmente, xilobiose e xilotriose. Para identificação do gene responsável pela produção da xilanase, foram utilizadas três estratégias: amplificação com primers degenerados, identificação de peptídeos por espectrometria de massas e sequenciamento do genoma da levedura. Um único gene (1265 pb) denominado Xyn10Cf foi identificado e o correspondente cDNA (1035 pb) foi clonado em Escherichia coli DH10B. O gene é interrompido por 6 íntrons, codifica um peptídeo sinal composto por 13 aminoácidos e a proteína madura é formada por 331 aminoácidos, tendo sua massa molecular estimada em 37,1 kDa (podendo conter cerca de 11 kDa de glicosilação). Com base na sequência de nucleotídeos e na caracterização da enzima purificada, a proteína foi classificada como membro da família GH10. Por fim, para comprovar a funcionalidade do gene identificado Xyn10Cf foi realizada a expressão na linhagem de Pichia pastoris GS115 sob o controle dos promotores álcool oxidase 1 (AOX1) ou gliceraldeído-3-fosfato desidrogenase (GAPDH), atingindo 5,66 U/mL e 7,67 U/mL, respectivamente, para 84 h de indução em frascos agitados / Abstract: Xylanases are enzymes that hydrolyze the glycosidic bonds between the xylose units of xylan, the main hemicellulosic compound. Due to the high availability in nature of this kind of material, the xylanases may be used in a wide range of industrial plants, including: textile, food and feed industries, bioconversion of lignocellulosic wastes, biobleaching of paper and pulp, and waste treatment. In order to describe novel enzymes for future applications, the goal of this work is to purify and characterize the xylanase produced by the basidiomycete Cryptococcus sp. LEB-AY10, a yeast previously isolated in the Atlantic Forest and selected by the production of a thermostable enzyme. First, the microorganism was identified at the species level and deposited as C. flavescens LEB-AY10 (CCT 7725); then, enzyme production was studied using the substrate sugarcane bagasse, pretreated by steam explosion in three different conditions, as well their corresponding soluble fractions, and supplemented with molasses or synthetic compounds. After selection of the treatment, experimental design techniques were used to assess the influence of cultivation variables and to increase the activity of produced xylanase. At optimized conditions, it was possible to increase activity by 5.6 times from initial assays, reaching 4.67 U/mL (at 50°C) or 8.33 U/mL (at 80°C) after 96 h of incubation. Later, the purification of the xylanase was performed in two chromatographic steps (ion exchange and gel permeation), in which it was possible to recover 45% of initial activity. The average molecular weight was estimated at 48 kDa. The enzyme showed optimal activity at 77.5°C and it was most stable at pH values near 5.3. At this pH, the half-lives of this enzyme were 9.2 min at 77.5°C and 33.74 h at 67°C. The kinetic parameters Km and vmax for Birchwood xylan were 4.13 g/L and 2.32 U/mL, respectively. The purified xylanase showed low activity of ?-xylosidase on 4-nitrophenyl-?-D-xilopiranosídeo (0.02 U/mg) and also showed some cellulase activity on carboxymethylcellulose (0.99 U/mg). The hydrolysis products of Beechwood xylan by the xylanase from C. flavescens LEB-AY10 were mainly xylobiose and xylotriose. For identification of the gene responsible for xylanase production, three strategies were used: amplification of degenerated primers, identification of peptides by mass spectrometry and yeast genome sequencing. A single gene (1265 pb) named Xyn10Cf was identified and the corresponding cDNA (1035 pb) was cloned into Escherichia coli DH10B. The gene is interrupted by 6 introns, it codifies a signal peptide of 13 amino acids and the mature protein is composed by 331 amino acids, with an estimated molecular mass of 37.1 kDa (it may contain around 11 kDa of glycosilation). Based on nucleotide sequencing and on characterization of the purified enzyme, the protein was classified as a member of GH10 family. Finally, to prove the functionality of the identified gene Xyn10Cf, the expression in Pichia pastoris GS115 strain was performed under the control of alcohol oxidase 1 (AOX1) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) promoters, reaching 5.66 U/mL and 7.67 U/mL, respectively, after 84 h of incubation in shaker flasks / Doutorado / Engenharia de Alimentos / Doutora em Engenharia de Alimentos

Antifungal drug resistance is a growing problem. Several mechanisms contribute to the development of resistance to antifungal agents. In South Africa, little is known about the antifungal susceptibility of local yeast isolates. The aim of this study was therefore to determine the antifungal susceptibility profile of local Candida species and Cryptococcus neoformans isolates and the molecular mechanisms of resistance to different antifungal agents in Pretoria. A total of 250 yeast isolates were collected from the diagnostic laboratory in the Department of Medical Microbiology at the University of Pretoria-National Health Laboratory Services. The isolates were subcultured on Sabouraud dextrose agar media for purity of yeast colonies. Identification to species level was performed using biochemical techniques. The antifungal susceptibility of 87 isolates was determined by the Etest for three azole antifungals (fluconazole, posaconazole and voriconazole), amphotericin B and caspofungin. Clinical breakpoint susceptibility was determined according to the CLSI clinical breakpoint reference methods. Polymerase chain reaction was performed on C. albicans isolates to amplify the ERG11 gene and the FKS1 gene. Sequencing was done for the amplification products and the sequence data were analysed by the CLC genome workbench software. Among the 250 isolates collected, Candida species accounted for 82.8% and C. neoformans accounted for 17.2% of the isolates. C. albicans was the most commonly isolated (76.8% of Candida species), of which 30% were resistant to caspofungin. Fluconazole resistance was detected in 56.7% of C. parapsilosis isolates, the highest fluconazole resistance among Candida species. Cross-resistance was found between fluconazole and voriconazole. Resistance to posaconazole was detected in 66.7% of C. glabrata isolates, whilst all other Candida species and C. neoformans isolates were fully susceptible. Furthermore, C. neoformans var. gattii isolates were less susceptible to azole antifungal agents than C. neoformans var. neoformans isolates. Molecular alterations are one of the mechanisms of resistance to azole and caspofungin antifungal agents. The amino acid substitutions D116E, K128T and V437I were detected in the ERG11 gene of two azole susceptible isolates. The new amino acid substitution E517Q was detected in the ERG11 gene of a resistant isolate. The S642L substitution was detected in the FKS1 gene of all the isolates that were caspofungin resistant and caspofungin susceptible. C. albicans was the most commonly isolated yeast species in Pretoria. Cross-resistance was detected between fluconazole and voriconazole. Therefore, these two agents are not a good alternative to use in the treatment of resistant isolates. With Candida species and C. neoformans isolates, there was less resistance to posaconazole than to fluconazole and voriconazole. The identification of the two varieties of C. neoformans is important in order to establish the differences in their antifungal susceptibility. Resistance to azole and caspofungin antifungal agents existed without the previously described molecular alterations in the ERG11 and FKS1 genes of resistant isolates. Further studies are required to explain the role of new amino acid substitutions, as well as the involvement of other mechanisms in resistance to antifungal drugs. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Medical Microbiology / unrestricted

No description available.

Um die Rolle von Interleukin-12p75 (IL-12p75) und Interleukin-12p40 (IL-12p40) in der Abwehr einer Kryptokokken-Infektion im Mausmodell zu untersuchen, wurden Mäuse auf 129Sv/Ev Stammhintergrund intraperitoneal und intranasal mit Cryptococcus neoformans (C. neoformans) infiziert. Dabei wurden die Unterschiede im Infektionsverlauf und in der Immunreaktion von Wildtyp-, IL-12p35-/- und IL-12p35/p40-/--Mäusen analysiert. Unterschiede zwischen den Wildtyp- und den IL-12p35-/--Mäusen lassen auf die Bedeutung von IL-12p75 schließen, wogegen Unterschiede zwischen IL-12p35-/-- und IL-12p35/p40-/--Mäusen auf die Rolle von IL-12p40 schließen lassen. Untersucht wurden sowohl die Erregerkonzentration in den Organen, Antigenspiegel im Blut, histologische Veränderungen und Serumantikörperkonzentrationen. Nach intraperitonealer Infektion war die Keimbelastung der Organe bei den Wildtyp-Mäusen geringer als bei beiden IL-12-/--Mausstämmen. Bei Wildtyp-Mäusen waren nicht nur weniger lebende Kryptokokken in den Organen zu finden, sondern auch weniger Kryptokokken Antigen im Serum als bei beiden IL-12-/--Mäusen nachweisbar. Das zeigt, dass IL-12p75 für die Kontrolle der intraperitonealen Infektion mit C. neoformans notwendig ist. IL-12p40 hatte ähnlich wie IL-12p75, wenn auch in etwas geringerem Masse, eine protektive Rolle bei der Erregerabwehr. Ohne IL-12p40 war eine Kontrolle der Infektion auf einem geringen Niveau der Keimbelastung nicht möglich. Besonders deutlich wurde dieses Phänomen beim Antigentiter bei den IL-12p35/p40-/--Mäusen. Durch das Fehlen von IL 12p40 wurde bei den IL-12p35/p40-/--Mäusen viel mehr Antigen über das Blut im Serum verteilt als bei den IL-12p35-/-- oder den Wildtyp-Mäusen. Die Wirtsreaktion bei einer Infektion mit C. neoformans geht mit der Bildung von Granulomen einher. Ohne IL-12p75 kam es zwar noch zur Bildung von Granulomen, diese zeigten aber eine veränderte zelluläre Zusammensetzung. Die IL-12p35/p40-/--Mäuse waren nicht zur Ausbildung von typischen Granulomen fähig. Bei ihnen kam es zu einer vermehrten Ansammlung von Kryptokokken fast ohne Entzündungszellen. IL-12p40 ist also für die Ausbildung einer zellulären Entzündungsreaktion notwendig. IL-12p40 ist auch für die Antikörperbildung gegen C. neoformans erforderlich. Die IL 12p35/p40-/--Mäuse waren kaum in der Lage, spezifische Antikörper gegen C. neoformans zu bilden. IL-12p75 ist für die Ausbildung einer Th1-Antwort notwendig. Infizierte Wildtyp-Mäuse produzierten doppelt soviel IgG2a, welches für ein Th1-Antwort typisch ist, wie die IL 12p35-/--Mäuse. Der intranasale Infektionsweg kommt der natürlichen aerogenen Infektion recht nahe. Deshalb wurde – zusätzlich zur intraperitonealen Infektion - dieser Infektionsweg zur Untersuchung der Immunantwort gegen C. neoformans berücksichtigt. Auch bei intranasaler Infektion ist IL-12p75 für die Kontrolle der Keimbelastung der Organe notwendig. Interessanterweise war die Keimbelastung der Lunge bei den IL-12p35-/--Mäusen etwas höher als bei den IL-12p35/p40-/--Mäusen. Bei den Wildtypmäusen war die Dissemination der Kryptokokken aus der Lunge in die Milz und ins Gehirn gering. Ein Fehlen von IL-12p75 bewirkte allerdings eine Besiedlung besonders des Gehirns. Nach intranasaler Infektion kam es in der Lunge von Wildtyp-Mäusen zu atypischen Granulomen mit zentraler Einschmelzung von Gewebe und Kryptokokken. Diese Reaktion war bei den IL-12p35-/--Mäusen noch stärker ausgeprägt als bei den Wildtyp-Mäusen. Bei den IL-12p35/p40-/--Mäusen blieb eine Gewebsreaktion größerer Areale aus. Es waren nur eine Aktivierung des BALT zu sehen. IL-12p40 ist demnach auch nach intranasaler Infektion für eine zelluläre Entzündungsreaktion notwendig. Möglicherweise kann sich diese Eigenschaft von IL-12p40 bei intranasaler Infektion in einer immunpathologischen Reaktion äußern, die bei IL-12p35-/--Mäusen für eine massive Infiltration der Lunge mit Entzündungszellen verantwortlich ist. Der Gehalt an Kryptokokken-spezifischen Antikörpern war nach intranasaler Infektion fünf- bis zehnmal höher als nach intraperitonealer Infektion. Der intranasale Infektionsweg zeigte also eine wesentlich ausgeprägtere humorale Antwort. Der Typ der Immunantwort schien sich im Gegensatz zur intraperitonealen Infektion in Richtung Th2 (d. h. verstärkte Antikörperbildung) verschoben zu haben. Sowohl nach intraperitonealer wie auch nach intranasaler Infektion mit C. neoformans lassen sich die immunstimulatorischen Aktivitäten von IL-12p75 und von IL-12p40 nachweisen, auch wenn diese sich in Abhängigkeit vom Infektionsweg etwas unterschiedlich manifestieren. / To analyse the role of interleukin-12p75 (IL-12p75) and interleukin-12p40 (IL-12p40) in the defence against Cryptococcus neoformans (C. neoformans) a murine infection model was established and studied. Mice of wild-tpye 129Sv/Ev background as well as IL-12p35-/- and IL-12p35/p40-/- 129Sv/Ev mice were infected intraperitoneally or intranasally with C. neoformans. The differences between the immune response of these genotypes were analysed. Comparing wild-type and IL-12p35-/--mice allows for conclusions related to the importance of IL-12p75, comparing IL-12p40-producing IL-12p35-/- mice with IL-12p35/p40-/- mice shows the importance of IL-12p40. Fungal organ burden, serum antigen levels, inflammatory cell responses, and antibody production were examined. The fungal organ load in wild-type mice was smaller than in both mutant IL-12-/--mice. In wild-type mice fewer cryptococci were found in organs and less cryptococcal antigen in serum than in IL-12p35-/- and IL-12p35/p40-/- mice. This underlines the importance of IL 12p75 for the control of the infection with C. neoformans. In addition, IL-12p40 was found to have a similar but weaker role as IL-12p75 in protection against C. neoformans. In the absence of IL-12p40 IL-12p35/p40-/- mice developed higher antigen titers than IL-12p35-/- and wild-type mice. The host response against infection with C. neoformans is associated with granuloma formation. Recruitment of inflammatory cells to granulomas was altered in the absence of IL 12p75. In addition, IL-12p40 contributed significantly to granuloma formation since IL 12p35/p40-/- mice developed no or only very poor granulomatous responses. Therefore, IL 12p40 is required for inflammatory cell responses. IL-12p40 was also found to be required for antibody production against C. neoformans. Infected IL-12p35/p40-/--mice had only very low levels of specific antibodies against C. neoformans. IL-12p75 is known to be essential for protective Th1 response against intracellular microorganisms. Th1 responses are commonly associated with the production of IgG2a. Infected wild-type mice produced 2-fold higher IgG2a levels than IL-12p35-/--mice. To adapt the infection model more to the natural infection mode the intraperitoneal infection route was changed to an intranasal route. Following intranasal infection IL-12p75 also proved to be necessary for control of the fungal organ load. Interestingly the organ load was higher in IL-12p35-/--mice than in IL-12p35/p40-/-mice which suggest a role of IL-12p40 in cell recruitment. Following intranasal application of cryptococci fungal dissemination to spleen and brain was reduced as compared to the intraperitoneal infection route. Without IL-12p75 dissemination of C. neoformans to the brain occured. This shows that IL-12p75 is involved in control of dissemination from lung to brain. The inflammatory response of IL-12p35-/--mice was stronger than the tissue response of wild-type mice. The massive tissue reactions of IL-12p35-/--mice caused big areas of diffuse cellular infiltration in their lungs. In IL-12p35/p40-/--mice inflammatory responses could be observed only in the peribronchial tissue. This shows that IL-12p40 is not only needed for a cellular inflammatory response following intraperitoneal but also following intranasal infection. Following intranasal infection IL-12p40 can induce immunopathological effects. Intranasal infection of mice with C. neoformans resulted in five to ten times higher antibody responses than intraperitoneal infection. This suggests that intranasal infection of mice results in a more Th2-biased humoral response. In summary, these experiments show that besides IL-12p75 also IL-12p40 contributes to cellular immunity against C. neoformans. The immunostimulatory properties of both, IL 12p75 and IL-12p40, can be observed after intraperitoneal and intranasal infection routes with similar but also distinct manifestations.

No description available.

Cryptococcus neoformans (C. neoformans), um fungo que se encontra disseminado em várias partes do mundo, inclusive no Brasil, é o responsável pela criptococose infecção oportunista mais comum em pacientes com a síndrome da imunodeficiência adquirida (SIDA). O caráter sistêmico da criptococose pode levar esses pacientes a óbito. A finalidade de se obter um diagnóstico laboratorial rápido e acurado de C. neoformans, principalmente para o seguimento dos pacientes HIV nos levou a investigar \"seqüências iniciadoras\" (Si) A, B e C das regiões 18SrDNA, 5,8SrDNA e ITS do Cryptococcus spp. Pela Nested PCR com estas seqüências, sugerimos a melhor delas para o desenvolvimento de um diagnóstico molecular em relação aos métodos usuais. Para tal, foram avaliadas amostras de soro e líquor de 39 pacientes, que já haviam recebido tratamento clínico. Todos os casos foram selecionados em grupos, como segue:7 com criptococose (GIII), 14 HIV positivos (GIV), 18 HIV positivos associados com a criptococose (GV) em relação a 10 controles - indivíduos sadios (GI) e amostras de culturas referência (GII). Os resultados obtidos pela Nested PCR com as \"Sis\" A, B e C foram comparados àqueles obtidos pelos métodos de diagnóstico convencionais. As análises desse estudo mostraram que as \"Sis\" A, B e C detectam C. neoformans com especificidade variada, tanto no soro (SiA 91,66%, SiB-100%, SiC 75%), como no líquor (SiA 83,33%, SiB 100% e SiC 75%) mas não apresentaram falso positivo, quando esses resultados foram comparados aos obtidos das culturas heterólogas (GVI). A SiB, em líquor, apresentou sensibilidade, acurácia, valores preditivo positivo e negativo, e especificidade de 100% para a detecção de C. neoformans da mesma forma que no soro, porém neste o valor preditivo negativo foi 89%, acurácia 94% e a sensibilidade 88%. Em amostras de soro e líquor, os testes Tinta da China e Látex, mostraram resultados falso positivos para o GIV e falso negativos nos grupos GIII e GV. As análises comparativas entre as técnicas mostraram que a ordem de eficiência da sensibilidade para detecção de C. neoformans no soro foi SiB>SiA=Látex>SiC e no líquor foi SiB> SiA>tinta da China>Látex=SiC. No soro, a especificidade entre as técnicas foi SiB>SiA=Látex>SiC e no líquor foi SiB=tinta da China>Látex>SiA>SiC. De acordo com nossos dados, concluímos que, independente da doença associada (HIV) ou se o paciente for tratado, a SiB foi a melhor seqüência para a detecção de C. neoformans, tanto em amostras diretamente de soro, como de líquor para todos os grupos estudados. Tendo em vista os fatos, acreditamos que, a aplicação da técnica da Nested PCR com a \"SiB\", em amostras de líquor e soro, é um método viável e acurado para realizar o diagnóstico molecular do C. neoformans em pacientes HIV. O uso de amostras de soro, para o segmento dos pacientes com SIDA, durante o tratamento, pode ser a forma menos invasiva em relação ao líquor para a detecção do C. neoformans, com vantagens sobre os métodos utilizados / Cryptococcus neoformans (C. neoformans), a fungus that is widespread in many parts of the world, including Brazil, is responsible for cryptococcosis the most common opportunistic infection in patients with acquired immunodeficiency syndrome (AIDS). The systemic character of cryptococcosis may be fatal. In order to obtain a rapid and accurate laboratory diagnosis to follow - up of HIV-cryptococcosis patients led us to investigate the sensibility and especificity of three primers (A, B and C) of 18SrDNA, 5,8SrDNA and ITS regions of Cryptococcus spp. Using Nested PCR with those primers we suggest the best among them to be used as a method of molecular diagnosis in relation to the usual techniques. For this purpose, the serum and cerebrospinal fluid (CSF) of 39 patients, who had received medical treatment, were evaluated. All cases were separated in groups, as follows: 7 with cryptococcosis (group III), 14 HIV positive (group IV), 18 HIV positive associated with cryptococcosis (group V) were compared to, 10 healthy subjects (group I) controls, as well as to reference cultures (group II) samples. The results obtained by nested PCR with primers A and B and C were compared to those obtained by conventional diagnostic methods. The analyses of primers A, B and C detected C. neoformans both in serum (SiA 91,6%, SiB-100%, SiC 75%), and in CSF (SiA 83,3%, SiB 100% e SiC 75%). Besides, they were specific for the identification of C. neoformans and showed that there were no false positives when compared with heterologous cultures (group VI) samples. The primer B in CSF showed 100% sensitivity, 100% accuracy and 100% predictive values (positive and negative), and 100% specificity for the detection of C. neoformans, the same that occurs in serum, but in this case, with 88% in sensitivity, 89% predictive value negative and 94% accuracy. In serum and CSF samples the China Ink and the Latex tests showed false positive results for group IV and false negative for III and V groups. The comparative analysis among the techniques (Nested PCR, China Ink, Latex) indicated that the efficiency order of sensitivity for the detection of C. neoformans were PrB> PrA = Latex> PrC in serum and PrB > PrA > China Ink> Latex = PrC in CSF. For the serum and CSF specificities the same techniques were used with the following results: PrB>PrA=Latex>PrC and PrB=China Ink>Latex>PrA>PrC. According to our data we conclude that, whether the patients had been under treatment or not, the Nested PCR by PrB was the best way to detect C. neoformans both in serum and in CSF for all groups. The following up of AIDS patients, throughout the course of therapy was found to be feasible, accurate and less invasive to detect C. neoformans by using serum samples (directly)