Genomic diversity of the human pathogen Paracoccidioides across the South American continent

Paracoccidioidomycosis (PCM) is a life-threatening systemic mycosis widely reported in the Gran Chaco ecosystem. The disease is caused by different species from the genus Paracoccidioides, which are all endemic to South and Central America. Here, we sequenced and analyzed 31 isolates of Paracoccidioides across South America, with particular focus on isolates from Argentina and Paraguay. The de novo sequenced isolates were compared with publicly available genomes. Phylogenetics and population genomics revealed that PCM in Argentina and Paraguay is caused by three distinct Paracoccidioides genotypes, P. brasiliensis (S1a and S1b) and P. restrepiensis (PS3). P. brasiliensis S1a isolates from Argentina are frequently associated with chronic forms of the disease. Our results suggest the existence of extensive molecular polymorphism among Paracoccidioides species, and provide a framework to begin to dissect the connection between genotypic differences in the pathogen and the clinical outcomes of the disease.Fil: Teixeira, Marcus de Melo. Universidade do Brasília; BrasilFil: Cattana, Maria Emilia. Universidad Nacional del Nordeste. Instituto de Medicina Regional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Matute, Daniel R.. University of North Carolina; Estados UnidosFil: Muñoz, José F.. Broad Institute Of Mit And Harvard; Estados UnidosFil: Arechavala, Alicia. Hospital Francisco J Muñiz; ArgentinaFil: Isbell, Kristin. University of North Carolina; Estados UnidosFil: Schipper, Rafael. Universidade do Brasília; BrasilFil: Santiso, Gabriela Maria. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Tracogna, Fernanda. Gobierno de la Provincia de Chaco. Hospital Julio Cecilio Perrando.; ArgentinaFil: Sosa, María de los Ángeles. Universidad Nacional del Nordeste. Instituto de Medicina Regional; ArgentinaFil: Cech, Norma. Hospital 4 de Junio; ArgentinaFil: Alvarado, Primavera. Instituto de Biomedicina Dr. Jacinto Convit; VenezuelaFil: Barreto, Laura. Instituto Superior de Formación Docente Salome Ureña; República DominicanaFil: Chacón, Yone. Provincia de Salta. Ministerio de Salud Pública. Hospital del Milagro; ArgentinaFil: Ortellado, Juana. Universidad Nacional de Asunción; ParaguayFil: Lima, Cleoni Mendes de. Universidade Federal de Rondonia; BrasilFil: Chang, Marilene Rodrigues. Universidade Federal do Mato Grosso do Sul; BrasilFil: Niño Vega, Gustavo. Universidad de Guanajuato; MéxicoFil: Yasuda, Maria Aparecida Shikanai. Universidade de Sao Paulo; BrasilFil: Felipe, Maria Sueli Soares. Universidade Catolica de Brasilia; BrasilFil: Negroni, Ricardo. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Cuomo, Christina A.. Broad Institute of MIT And Harvard; Estados UnidosFil: Barker, Bridget. Tgen Northern Arizona University; Estados UnidosFil: Giusiano, Gustavo Emilio. Universidad Nacional del Nordeste. Instituto de Medicina Regional; Argentina. Universidad Nacional del Nordeste. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentin

Cell walls of the dimorphic fungal pathogens Sporothrix schenckii and Sporothrix brasiliensis exhibit bilaminate structures and sloughing of extensive and intact layers

This work was supported by the Fundação Carlos Chagas de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), grants E-26/202.974/2015 and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), grants 229755/2013-5, Brazil. LMLB is a senior research fellow of CNPq and Faperj. NG acknowledged support from the Wellcome Trust (Trust (097377, 101873, 200208) and MRC Centre for Medical Mycology (MR/N006364/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

4to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

Este volumen acoge la memoria académica de la Cuarta edición del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2017, desarrollado entre el 29 de noviembre y el 1 de diciembre de 2017 y organizado por la Universidad Politécnica Salesiana (UPS) en su sede de Guayaquil. El Congreso ofreció un espacio para la presentación, difusión e intercambio de importantes investigaciones nacionales e internacionales ante la comunidad universitaria que se dio cita en el encuentro. El uso de herramientas tecnológicas para la gestión de los trabajos de investigación como la plataforma Open Conference Systems y la web de presentación del Congreso http://citis.blog.ups.edu.ec/, hicieron de CITIS 2017 un verdadero referente entre los congresos que se desarrollaron en el país. La preocupación de nuestra Universidad, de presentar espacios que ayuden a generar nuevos y mejores cambios en la dimensión humana y social de nuestro entorno, hace que se persiga en cada edición del evento la presentación de trabajos con calidad creciente en cuanto a su producción científica. Quienes estuvimos al frente de la organización, dejamos plasmado en estas memorias académicas el intenso y prolífico trabajo de los días de realización del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad al alcance de todos y todas

Expression of Paracoccidioides brasiliensis AMY1 in a Histoplasma capsulatum amy1 mutant, relates an α-(1,4)-amylase to cell wall α-(1,3)-glucan synthesis.

In the cell walls of the pathogenic yeast phases of Paracoccidioides brasiliensis, Blastomyces dermatitidis and Histoplasma capsulatum, the outer α-(1,3)-glucan layer behaves as a virulence factor. In H. capsulatum, an α-(1,4)-amylase gene (AMY1) is essential for the synthesis of this polysaccharide, hence related to virulence. An orthologous gene to H. capsulatum AMY1 was identified in P. brasiliensis and also labeled AMY1. P. brasiliensis AMY1 transcriptional levels were increased during the yeast phase, which correlates with the presence of α-(1,3)-glucan as the major yeast cell wall polysaccharide. Complementation of a H. capsulatum amy1 mutant strain with P. brasiliensis AMY1, suggests that P. brasiliensis Amy1p may play a role in the synthesis of cell wall α-(1,3)-glucan. To study some biochemical properties of P. brasiliensis Amy1p, the enzyme was overexpressed, purified and studied its activity profile with starch and amylopeptin. It showed a relatively higher hydrolyzing activity on amylopeptin than starch, producing oligosaccharides from 4 to 5 glucose residues. Our findings show that P. brasiliensis Amy1p produces maltooligosaccharides which may act as a primer molecule for the fungal cell wall α-(1,3)-glucan biosynthesis by Ags1p

Fungal Strategies to Evade the Host Immune Recognition

The recognition of fungal cells by the host immune system is key during the establishment of a protective anti-fungal response. Even though the immune system has evolved a vast number of processes to control these organisms, they have developed strategies to fight back, avoiding the proper recognition by immune components and thus interfering with the host protective mechanisms. Therefore, the strategies to evade the immune system are as important as the virulence factors and attributes that damage the host tissues and cells. Here, we performed a thorough revision of the main fungal tactics to escape from the host immunosurveillance processes. These include the composition and organization of the cell wall, the fungal capsule, the formation of titan cells, biofilms, and asteroid bodies; the ability to undergo dimorphism; and the escape from nutritional immunity, extracellular traps, phagocytosis, and the action of humoral immune effectors

Fungal strains and plasmids used in this study.

<p><i>hph</i>, hygromycin phosphotransferase (hygromycin resistance).</p><p>PaURA5, Podospora anserina URA5 gene.</p><p>PbAMY1, P. brasiliensis AMY1 gene.</p><p><i>P_CBP1,</i> 889 bp upstream of the <i>H. capsulatum CBP1</i> gene.</p><p><i>P_AMY1,</i> 1.950 bp upstream of the <i>P. brasiliensis AMY1</i> gene.</p>†<p>Defined by <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050201#pone.0050201-Matute1" target="_blank">[2]</a>.</p

Virulence recovery of <i>H. capsulatum amy1</i>-null yeasts complemented with the <i>P. brasiliensis AMY1</i> gene.

<p>Macrophage survival is measured as the remaining macrophage DNA after incubation of macrophages with <i>Histoplasma</i> yeasts. Macrophage DNA remaining at 8 days post infection was normalized to uninfected populations of macrophages. Data represent three independent assays. Error bars represent the standard deviation. (*)Unpaired <i>t</i>-tests between <i>amy1</i>-Δ+pCR41 and <i>amy1</i>-Δ+pEC87 or pEC90; <i>P</i>-value <0.0001.</p

Colony morphology and α-(1,3)-glucan immunostaining.

<p>(<b>p</b>) and (<b>u</b>) <i>H. capsulatum amy1</i>-null mutant complemented with <i>P. brasiliensis AMY1</i> under the <i>CBP1</i> promoter (pEC87) or <i>AMY1</i> promoter (pEC90), respectively, is able to restore the rough phenotype exhibited by (<b>a</b>) the parental strain, as well as its α-(1,3)-glucan content and distribution. The smooth colony morphology correlates with loss of α-(1,3)-glucan from yeast cell walls as shown by immunofluorescence of (<b>f</b>) <i>ags1</i>-Δ mutant yeasts or (<b>k</b>) <i>amy1</i>-Δ mutant yeasts.</p

Phylogenetic tree of α-amylase proteins from representative taxa of the three domains of life.

<p>Abbreviations used and sources of the α-amylases are defined in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050201#pone.0050201.s003" target="_blank">Table S1</a>. The tree is based on the alignment made in CLUSTAL W of the partial sequences encoding the (β/α)₈ barrel. Two separate groups of fungal α-amylases, intracellular (circled, GH13_5) and extracellular (GH13_1), are distinctly noted. The branch length is proportional to the sequence divergence. Numbers along branches are bootstrap values (1000 replicates). The scale bar (bottom-left corner) indicates 0.05 amino acid substitutions per site.</p