The transcription factor Pdr802 regulates Titan cell formation and pathogenicity of Cryptococcus neoformans

The pathogenic yeast Cryptococcus neoformansC. neoforman

The calcium transporter Pmc1 provides Ca2+ tolerance and influences the progression of murine cryptococcal infection

Submitted by Fabricia Pimenta ([email protected]) on 2019-01-31T18:17:20Z No. of bitstreams: 1 ve_Marcio_Rodrigues_etal_CDTS_2013c.pdf: 654095 bytes, checksum: 2c4916d4e295d8e8485b645fd88d7f58 (MD5)Approved for entry into archive by Fabricia Pimenta ([email protected]) on 2019-03-07T20:00:12Z (GMT) No. of bitstreams: 1 ve_Marcio_Rodrigues_etal_CDTS_2013c.pdf: 654095 bytes, checksum: 2c4916d4e295d8e8485b645fd88d7f58 (MD5)Made available in DSpace on 2019-03-07T20:00:12Z (GMT). No. of bitstreams: 1 ve_Marcio_Rodrigues_etal_CDTS_2013c.pdf: 654095 bytes, checksum: 2c4916d4e295d8e8485b645fd88d7f58 (MD5) Previous issue date: 2013-10Universidade Federal do Rio Grande do Sul. Centro de Biotecnologia. Porto Alegre, RS, Brasil.Universidade Federal do Rio Grande do Sul. Centro de Biotecnologia. Porto Alegre, RS, Brasil.Universidade Federal do Rio Grande do Sul. Centro de Biotecnologia. Porto Alegre, RS, Brasil.Universidade Federal do Rio de Janeiro. Instituto de Microbiologia Professor Paulo de G oes. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Centro de Desenvolvimento Tecnológico em Saúde. Rio de Janeiro, RJ, Brasil / Universidade Federal do Rio de Janeiro. Instituto de Microbiologia Professor Paulo de G oes. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio Grande do Sul. Centro de Biotecnologia. Porto Alegre, RS, Brasil.Universidade Federal do Rio Grande do Sul. Centro de Biotecnologia. Porto Alegre, RS, Brasil.The Ca(2+)-calcineurin signaling pathway in the human fungal pathogen Cryptococcus neoformans is essential for adaptation to the host environment during infection. Calcium transporters regulate cytosolic calcium concentrations, providing Ca(2+) loading into storage organelles. The three calcium transporters that have been characterized in C. neoformans, Cch1, Eca1 and Vcx1, are required for fungal virulence, supporting a role for calcium-mediated signaling in cryptococcal pathogenesis. In the present study, we report the functional characterization of the putative vacuolar calcium ATPase Pmc1 in C. neoformans. Our results demonstrate that Pmc1 provides tolerance to high Ca(2+) concentrations. The double knockout of C. neoformans PMC1 and VCX1 genes impaired the intracellular calcium transport, resulting in a significant increase in cytosolic calcium levels. Furthermore, Pmc1 was essential for both the progression of pulmonary infection and brain colonization in mice, emphasizing the crucial role of calcium signaling and transport for cryptococcal pathogenesis

Modulation of Zinc Homeostasis in Acanthamoeba castellanii as a Possible Antifungal Strategy against Cryptococcus gattii

Cryptococcus gattii is a basidiomycetous yeast that can be found in the environment and is one of the agents of cryptococcosis, a life-threatening disease. During its life cycle, cryptococcal cells take hold inside environmental predators such as amoebae. Despite their evolutionary distance, macrophages and amoebae share conserved similar steps of phagocytosis and microbial killing. To evaluate whether amoebae also share other antifungal strategies developed by macrophages, we investigated nutritional immunity against cryptococcal cells. We focused on zinc homeostasis modulation in Acanthamoeba castellanii infected with C. gattii. The intracellular proliferation rate (IPR) in amoebae was determined using C. gattii R265 and mutants for the ZIP1 gene, which displays defects of growth in zinc-limiting conditions. We detected a reduced IPR in cells lacking the ZIP1 gene compared to wild-type strains, suggesting that amoebae produce a low zinc environment to engulfed cells. Furthermore, flow cytometry analysis employing the zinc probe Zinpyr-1 confirmed the reduced concentration of zinc in cryptococcal-infected amoebae. qRT-PCR analysis of zinc transporter-coding genes suggests that zinc export by members of the ZnT family would be involved in the reduced intracellular zinc concentration. These results indicate that amoebae may use nutritional immunity to reduce fungal cell proliferation by reducing zinc availability for the pathogen

Genotypic and Phenotypic Diversity of Cryptococcus gattii VGII Clinical Isolates and Its Impact on Virulence

The Cryptococcus gattii species complex harbors the main etiological agents of cryptococcosis in immunocompetent patients. C. gattii molecular type VGII predominates in the north and northeastern regions of Brazil, leading to high morbidity and mortality rates. C. gattii VGII isolates have a strong clinical relevance and phenotypic variations. These phenotypic variations among C. gattii species complex isolates suggest that some strains are more virulent than others, but little information is available related to the pathogenic properties of those strains. In this study, we analyzed some virulence determinants of C. gattii VGII strains (CG01, CG02, and CG03) isolated from patients in the state of Piauí, Brazil. The C. gattii R265 VGIIa strain, which was isolated from the Vancouver outbreak, differed from C. gattii CG01, CG02 and CG03 isolates (also classified as VGII) when analyzed the capsular dimensions, melanin production, urease activity, as well as the glucuronoxylomannan (GXM) secretion. Those differences directly reflected in their virulence potential. In addition, CG02 displayed higher virulence compared to R265 (VGIIa) strain in a cryptococcal murine model of infection. Lastly, we examined the genotypic diversity of these strains through Multilocus Sequence Type (MLST) and one new subtype was described for the CG02 isolate. This study confirms the presence and the phenotypic and genotypic diversity of highly virulent strains in the Northeast region of Brazil

Atividades de diferenciação curricular na Educação Pré-Escolar e no 1.º Ciclo do Ensino Básico

Mestrado, Educação Pré-Escolar e Ensino do 1.º Ciclo do Ensino Básico, 11 de Maio de 2017, Universidade dos Açores.O presente relatório de estágio surge no seguimento dos Estágios Pedagógicos I e II, do 2.º ano do curso de Mestrado em Educação Pré-Escolar e Ensino do 1.º Ciclo do Ensino Básico, com o intuito de ficar apto a exercer a docência. O tema foco deste trabalho prende-se com a implementação de atividades de diferenciação curricular e com o reconhecimento da relevância do currículo, por parte dos alunos, com o objetivo de compreender se, a implementação destas práticas, contribuem ou não para um maior reconhecimento da relevância do currículo. Deste modo, e para atingir o que era proposto, foi necessário recorrer a uma investigação de cariz qualitativo, utilizando três técnicas de recolha de dados, sendo elas a observação direta e não participante, a entrevista a crianças, e o diário de bordo. No presente trabalho consta, numa primeira parte, a fundamentação teórica, que foi o sustento do mesmo e o ponto de referência aquando da análise de dados; numa segunda parte, a descrição dos objetivos e dos processos metodológicos utilizados; e, por fim, a análise e conclusões dos dados recolhidos ao longo dos estágios. São diversos os resultados obtidos com a investigação realizada durante este estágio. Por exemplo, a nível das práticas de diferenciação implementadas pelos educadores/professores nas salas de aula, já há uma maior preocupação em fazer com que as crianças compreendam o que se pretende. Para tal, os profissionais de educação recorrem a exemplos reais do quotidiano das crianças, fazendo uma adaptação ao nível da indicação da tarefa e das fichas de trabalho realizadas. No que concerne ao reconhecimento da relevância curricular por parte dos alunos, verificou-se que ainda há crianças que remetem bastante para a importância das aprendizagens que tem fim na própria escola, não encontrando, muitas vezes, relação com a vida extraescolar. No entanto, aquando das entrevistas finais, notou-se uma maior referência às atividades que lhes poderiam ser úteis, facto que raramente se tinha verificado inicialmente.ABSTRACT: This internship report is a follow up of the Pedagogic Stages I and II, in the 2nd year of the Masters course in Pre-School Education and the 1st Cycle of Basic Education. This report is necessary to be able to exercise teaching. The theme focus of this work is related to the implementation of curriculum differentiation activities and the recognition of the curricular relevance by the students, with the objective to understand if the implementation of these practices contributes or not to a greater recognition of the curricular relevance. That way, and to achieve what was proposed, it was necessary to do a qualitative nature research using three data collection techniques, which were the direct and nonparticipant observation, interview the children, and the logbook. Primarily, this report is composed by a theoretical approach that was the foundation and the point of reference of this work. Secondly, there was an explanation of the purposes and the methodological processes used. Finally, there was an analysis of the data recovered during the internship. There are some results obtained with this report that are worth to be mentioned. For example, there is a major concern in making children understand what the teachers want. Therefore, the professionals use some differentiation techniques in the classrooms. For example, they make an adaptation when giving a task or a work sheet. There are still children that can’t understand that what they learn in school, it’s absolutely necessary in their daily lives. Nevertheless, in the final interviews, the children made a reference to the activities that could be helpful in their lives, showing that there was a difference in the mentality

Additional file 13: of sRNAs as possible regulators of retrotransposon activity in Cryptococcus gattii VGII

Retrotransposon-associated synteny breakpoints 5 in R265. Figure shows a multiple genome alignment of VGII strains. Syntenic blocks shared by genomes are represented with the same color and are connected by lines; red lines indicate chromosome or supercontig boundaries. The location of associated retrotransposons R265.38 and R265.20 in supercontig 13 of R265 strain is represented by the black rectangle. Microsynteny disruption by retrotransposon insertion can be observed as white spaces inside blocks. (JPG 487 kb

Additional file 9: of sRNAs as possible regulators of retrotransposon activity in Cryptococcus gattii VGII

Retrotransposon-associated synteny breakpoints 1 in R265. Figure shows a multiple genome alignment of VGII strains. Syntenic blocks shared by genomes are represented with the same color and are connected by lines; red lines indicate chromosome or supercontig boundaries. The location of associated retrotransposons R265.12 and R265.13 in supercontig 7 of R265 strain is represented by the black rectangle. Microsynteny disruption by retrotransposon insertion can be observed as white spaces inside blocks. (JPG 483 kb

Additional file 21: of sRNAs as possible regulators of retrotransposon activity in Cryptococcus gattii VGII

Reads mapping profile of highly repressed retrotransposons. Visualization of mapped reads profile from mRNA and sRNA libraries in highly repressed sequences R265.36 and R265.37. Abbreviations: Long Terminal Repeats (LTR), Integrase (INT), Ribonuclease H (RNAse), Reverse Transcriptase (RT), Aspartyl Protease (PROT). (JPG 287 kb