Person:
Román González, Elvira

First Name

Elvira

Last Name

Román González

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Farmacia

Department

Microbiología y Parasitología

Area

Microbiología

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Now showing 1 - 10 of 16

MicroMundo: una aproximación a la perspectiva One Health de Salud Global mediante Aprendizaje-Servicio integrando diversos niveles educativos
(2022-03-16) González Zorn, Bruno; Román González, Elvira; Molina Martín, María; Martín Brieva, Humberto; Escudero García-Calderón, José Antonio; Rodríguez Fernández, Carmina; Bezos Garrido, Javier; Álvarez Sánchez, Julio; Pérez Sancho, Marta; Amaro Torres, Francisco; Jimenez Cid, Victor; Suárez Rodríguez, Mónica; Patiño Alvarez, Belén; Calvo de Pablo, Pilar; Fernández-Acero Bascones, Teresa; Pavón Vergés, Mónica; Sanz Santamaría, Ana Belén; Díaz del Toro, Silvia; González Rubio, Gema; Vázquez Estévez, Covadonga; Gil Serna, Jéssica; Jiménez Gutiérrez, Elena; del Val Oriza, Elba; Valenti Sanguino, Marta; Sellers Moya, Ángela; Sastre Vergara, Lucía
MicroMundo es la adaptación a Aprendizaje-Servicio (ApS) de la estrategia de crowdsourcing y ciencia ciudadana internacional Tiny Earth. Su objetivo de servicio esencial es acercar la cultura científica, la perspectiva One Health y la investigación biomédica a la sociedad, poniendo el foco en jóvenes estudiantes para fomentar la vocación por formación en Grados STEM y por la investigación. La pandemia de COVID-19 y sus consecuencias han puesto de manifiesto la urgencia de acercar la cultura científica en el ámbito de la Biomedicina y la Salud Pública a la sociedad e implicar en esta tarea a nuestros estudiantes. Pero también la pandemia ha impuesto cambios en nuestro esquema de trabajo durante este curso, lo que nos ha obligado a trabajar on-line en lugar de llevar a cabo las características actividades experimentales de aprendizaje activo en las que se fundamenta el proyecto en condiciones normales. Manteniendo los mismos objetivos, las intervenciones en los 20 Colegios e Institutos en los que hemos realizado el proyecto se han enfocado en la elaboración de materiales divulgativos e intervenciones en la comunidad por parte de los jóvenes estudiantes, de manera coordinada por nuestros estudiantes universitarios y la organización de un Simposio on-line de ámbito nacional donde se expusieron y compartieron las diversas iniciativas. La elevada participación en el Simposio, de inscripción gratuita (más de 500 inscritos) y la calidad de las 69 ponencias propuestas, la mayoría de manera conjunta por alumnos de instituto y universitarios, avala el enorme éxito de la iniciativa virtual y la consecución de objetivos. El material generado (videojuegos, entornos educativos virtuales, paisajes de aprendizaje, escape rooms, videos, campañas en Instagram o Tik Tok, blogs, etc) será muy valioso como material de apoyo en sucesivas ediciones de MicroMundo. Todo este material se irá divulgando en el portal www.esmisionposible.com las redes sociales @EsMisionPosible, gestionados por el proyecto. En resumen, consideramos que nuestro proyecto que implica tanto a estudiantes y profesores de centros educativos de Educación Secundaria y Bachillerato en la CAM a, como a profesores y estudiantes universitarios de los ámbitos de Sanidad Humana, Animal y Medioambiental de manera transversal e interfacultativa, ha afrontado con éxito el reto de adaptar el proyecto a la situación epidemiológica, reforzándolo con actividades no presenciales orientadas a consolidar una comunidad MicroMundo virtual en la que los estudiantes pueden compartir sus experiencias en la divulgación del problema de la resistencia y el fomento de la investigación para el descubrimiento de nuevos antimicrobianos.
Micromundo@ucm: investigación y concienciación contra la pandemia silenciosa de la resistencia a antibióticos
(2022) Gómez Albarrán, Carolina; Amaro Torres, Francisco; Molina Martín, María; Jiménez Gutiérrez, Elena; Sellers Moya, Ángela; Gil Serna, Jéssica; González Rubio, Gema; De Francisco, Patricia; Prieto Orzanco, Alicia María; González de Figueras, Carolina; Fernández-Acero Bascones, Teresa; Maestro García-Donas, Beatriz; Román González, Elvira; Calvo de Pablo, Pilar; Vázquez Estévez, Covadonga; Rodríguez Fernández, Carmina; Sempere García, Julio; Domenech Lucas, Mirian; Serna Bernaldo, Carlos; Díaz del Toro, Silvia; Patiño Álvarez, Belén; Blanco Torres, Paula; Valdés González, José Antonio; Rubio Lozano, Alba Victoria; Lavilla García, Beatriz; del Val Oriza, Elba; Romero Martínez, Beatriz; Valenti Sanguino, Marta; López Montesino, Sara; Martínez López, Raquel; Escudero García-Calderón, José Antonio; Sastre Vergara, Lucía; García Pastor, Lucía; Pérez Sancho, Marta; Kieffer, Nicolas; Bezos Garrido, Javier; Hipólito Carrillo de Albornoz, Alberto; Muñoz Atienza, Estefanía; Trigo da Roza, Filipa; Suárez Rodríguez, Mónica; García Bezanquen, Nerea; Marín Martínez, María; Vergara González, Ester; González Zorn, Bruno; Borrero del Pino, Juan; Jiménez Cid, Víctor
Actualmente se estima que las resistencias antibióticas se cobran 1.270.000 vidas anualmente a nivel global. Es necesario contribuir desde multiples ángulos a preservar la efectividad de os antibióticos y descubrir nuevas etsrategias terapéuticas. MicroMundo es un proyecto de Aprendizaje-Servicio y Ciencia Ciudadana que pretende crear cultura científica y concienciación en cuestiones de Salud Global en los jóvenes. Se pretende que sean los más jóvenes, los estudiantes de ESO y Bachillerato, los responsables de la transmisión de ese conocimiento a la comunidad. Pero un segundo objetivo, no menos importante, es el de generar y potenciar vocaciones STEM e interés por el I+D en Biomedicina. Para conseguir estos objetivos, diversos equipos de estudiantes universitarios imparten y coordinan el proyecto en colegios e institutos de su comunidad, coordinados por sus tutores (profesores e investigadores del área de Microbiología de las Facultades de Farmacia, Medicina, Veterinaria y Biología, cubriendo los tres vértices del triángulo One Health: salud humana, animal y medioambiental). En la UCM, durante el curso 2021-22, treinta y dos equipos de han trabajado en unos treinta colegios e institutos, implicando a unos 600 estudiantes preuniversitarios en el trabajo experimental del proyecto.
Non-canonical Activities of Hog1 Control Sensitivity of Candida albicans to Killer Toxins From Debaryomyces hansenii
(2018-05-03) Morales-Menchén, Ana; Navarro García, Federico; Guirao-Abad, José P; Román González, Elvira; Prieto, Daniel; Coman, Ioana V; Pla Alonso, Jesús; Alonso Monge, Rebeca
Certain yeasts secrete peptides known as killer toxins or mycocins with a deleterious effect on sensitive yeasts or filamentous fungi, a common phenomenon in environmental species. In a recent work, different () strains isolated from a wide variety of cheeses were identified as producing killer toxins active against and . We have analyzed the killer activity of these toxins in mutants defective in MAPK signaling pathways and found that the lack of the MAPK Hog1 (but not Cek1 or Mkc1) renders cells hypersensitive to mycocins while mutants lacking other upstream elements of the pathway behave as the wild type strain. Point mutations in the phosphorylation site (T174A-176F) or in the kinase domain (K52R) of gene showed that both activities were relevant for the survival of to killer toxins. Moreover, Hog1 phosphorylation was also required to sense and adapt to osmotic and oxidative stress while the kinase activity was somehow dispensable. Although the addition of supernatant from the killer toxin- producing 242 strain (-242) induced a slight intracellular increase in Reactive Oxygen Species (ROS), overexpression of cytosolic catalase did not protect against this mycocin. This supernatant induced an increase in intracellular glycerol concentration suggesting that this toxin triggers an osmotic stress. We also provide evidence of a correlation between sensitivity to -242 killer toxin and resistance to Congo red, suggesting cell wall specific alterations in sensitive strains.
Deletion of the SKO1 Gene in a hog1 Mutant Reverts Virulence in Candida albicans
(MDPI, 2019) Urrialde, Verónica; Prieto Prieto, Daniel; Hidalgo Vico, Susana; Román González, Elvira; Pla Alonso, Jesús; Alonso Monge, Rebeca
Candida albicans displays the ability to adapt to a wide variety of environmental conditions, triggering signaling pathways and transcriptional regulation. Sko1 is a transcription factor that was previously involved in early hypoxic response, cell wall remodeling, and stress response. In the present work, the role of sko1 mutant in in vivo and ex vivo studies was explored. The sko1 mutant behaved as its parental wild type strain regarding the ability to colonize murine intestinal tract, ex vivo adhesion to murine gut epithelium, or systemic virulence. These observations suggest that Sko1 is expendable during commensalism or pathogenesis. Nevertheless, the study of the hog1 sko1 double mutant showed unexpected phenotypes. Previous researches reported that the deletion of the HOG1 gene led to avirulent C. albicans mutant cell, which was, therefore, unable to establish as a commensal in a gastrointestinal murine model. Here, we show that the deletion of sko1 in a hog1 background reverted the virulence of the hog1 mutant in a systemic infection model in Galleria mellonella larvae and slightly improved the ability to colonize the murine gut in a commensalism animal model compared to the hog1 mutant. These results indicate that Sko1 acts as a repressor of virulence related genes, concluding that Sko1 plays a relevant role during commensalism and systemic infection.
Implementation of a CRISPR-Based System for Gene Regulation in Candida albicans.
(American Society for Microbiology, 2019-02-13) Román González, Elvira; Coman, Ioana V; Prieto, Daniel; Alonso Monge, Rebeca; Pla Alonso, Jesús
Clustered regularly interspaced short palindromic repeat (CRISPR) methodology is not only an efficient tool in gene editing but also an attractive platform to facilitate DNA, RNA, and protein interactions. We describe here the implementation of a CRISPR-based system to regulate expression in the clinically important yeast By fusing an allele of Cas9 devoid of nuclease activity to a transcriptional repressor (Nrg1) or activator (Gal4), we were able to show specific repression or activation of the tester gene , encoding the cytosolic catalase. We generated strains where a 1.6-kbp upstream regulatory region of controls the expression of the green fluorescent protein (GFP) and demonstrated the functionality of the constructs by quantitative PCR (qPCR), flow cytometry, and analysis of sensitivity/resistance to hydrogen peroxide. Activation and repression were strongly dependent on the position of the complex in this regulatory region. We also improved transcriptional activation using an RNA scaffolding strategy to allow interaction of inactive variants of Cas9 (dCas9) with the RNA binding protein MCP (monocyte chemoattractant protein) fused to the VP64 activator. The strategy shown here may facilitate the analysis of complex regulatory traits in this fungal pathogen. CRISPR technology is a new and efficient way to edit genomes, but it is also an appealing way to regulate gene expression. We have implemented CRISPR as a gene expression platform in using fusions between a Cas9 inactive enzyme and specific repressors or activators and demonstrated its functionality. This will allow future manipulation of complex virulence pathways in this important fungal pathogen.
Educating in antimicrobial resistance awareness: adaptation of the Small World Initiative program to service-learning.
(Oxford University Press, 2018-09-01) Valderrama, María José; González Zorn, Bruno; Calvo de Pablo, Pilar; Díez Orejas, Rosalía; Fernández Acero, Teresa; Gil-Serna, Jessica; Juan, Lucía de; Martín Brieva, Humberto; Molina Martín, María; Navarro García, Federico; Patiño, Belén; Pla Alonso, Jesús; Prieto, Daniel; Rodríguez Fernández, Carmina; Román González, Elvira; Sanz Santamaría, Ana Belén; Silóniz, María Isabel de; Suárez, Mónica; Vázquez, Covadonga; Jiménez Cid, Víctor
The Small World Initiative (SWI) and Tiny Earth are a consolidated and successful education programs rooted in the USA that tackle the antibiotic crisis by a crowdsourcing strategy. Based on active learning, it challenges young students to discover novel bioactive-producing microorganisms from environmental soil samples. Besides its pedagogical efficiency to impart microbiology content in academic curricula, SWI promotes vocations in research and development in Experimental Sciences and, at the same time, disseminates the antibiotic awareness guidelines of the World Health Organization. We have adapted the SWI program to the Spanish academic environment by a pioneering hierarchic strategy based on service-learning that involves two education levels (higher education and high school) with different degrees of responsibility. Throughout the academic year, 23 SWI teams, each consisting of 3-7 undergraduate students led by one faculty member, coordinated off-campus programs in 22 local high schools, involving 597 high school students as researchers. Post-survey-based evaluation of the program reveals a satisfactory achievement of goals: acquiring scientific abilities and general or personal competences by university students, as well as promoting academic decisions to inspire vocations for science- and technology-oriented degrees in younger students, and successfully communicating scientific culture in antimicrobial resistance to a young stratum of society.
The Mkk2 MAPKK Regulates Cell Wall Biogenesis in Cooperation with the Cek1-Pathway in Candida albicans
(Public Library of Science, 2015-07-21) Román González, Elvira; Alonso Monge, Rebeca; Miranda, Alberto; Pla Alonso, Jesús
The cell wall integrity pathway (CWI) plays an important role in the biogenesis of the cell wall in Candida albicans and other fungi. In the present work, the C. albicans MKK2 gene that encodes the putative MAPKK of this pathway was deleted in different backgrounds and the phenotypes of the resultant mutants were characterised. We show here that Mkk2 mediates the phosphorylation of the Mkc1 MAPK in response to cell wall assembly interfering agents such as zymolyase or tunicamycin and also to oxidative stress. Remarkably, mkk2 and mkc1 mutants display related but distinguishable- cell wall associated phenotypes and differ in the pattern of MAPK phosphorylation under different stress conditions. mkk2 and mkc1 mutants display an altered expression of GSC1, CEK1 and CRH11 genes at different temperatures. Combined deletion of MKK2 with HST7 supports a cooperative role for the Cek1-mediated and CWI pathways in regulating cell wall architecture under vegetative growth. However, and in contrast to Mkc1, Mkk2 does not seem to play a role in the virulence of C. albicans in the mouse systemic model or the Galleria mellonella model of infection.
TUP1-mediated filamentation in Candida albicans leads to inability to colonize the mouse gut.
(Future Medicine, 2018-06-01) Román González, Elvira; Huertas, Blanca; Prieto, Daniel; Díez Orejas, Rosalía; Pla Alonso, Jesús
AIM To investigate the role of Candida albicans TUP1-mediated filamentation in the colonization of the mice gut. MATERIALS & METHODS We used molecular genetics to generate a strain where filamentation is regulated by altering the expression of the TUP1 gene with tetracyclines. RESULTS The colonization rates reached with the TUP1-RFP strain were lower compared with wild-type strain and completely absent after induction of filamentation. No differences in the susceptibility to bile salts nor in the adhesion to the mouse intestine epithelium were observed. CONCLUSION Blockage of C. albicans in a filamentous form impedes gut cell colonization in the mouse.
Identification of Clinical Isolates of Candida albicans with Increased Fitness in Colonization of the Murine Gut
(MDPI, 2021-08-27) Alonso Monge, Rebeca; Prieto Prieto, Antonio Daniel; Coman, Ioana V.; Rochas, Sara; Arana, David M.; Hidalgo Vico, Susana; Pla Alonso, Jesús; Román González, Elvira
The commensal and opportunistic pathogen Candida albicans is an important cause of fungal diseases in humans, with the gastrointestinal tract being an important reservoir for its infections. The study of the mechanisms promoting the C. albicans commensal state has attracted considerable attention over the last few years, and several studies have focused on the identification of the intestinal human mycobiota and the characterization of Candida genes involved in its establishment as a commensal. In this work, we have barcoded 114 clinical C. albicans isolates to identify strains with an enhanced fitness in a murine gastrointestinal commensalism model. The 114 barcoded clinical isolates were pooled in four groups of 28 to 30 strains that were inoculated by gavage in mice previously treated with antibacterial therapy. Eight strains that either exhibited higher colonization load and/or remained in the gut after antibiotic removal were selected. The phenotypic analysis of these strains compared to an RFP-tagged SC5314 wild type strain did not reveal any specific trait associated with its increased colonization; all strains were able to filament and six of the eight strains displayed invasive growth on Spider medium. Analysis of one of these strains, CaORAL3, revealed that although mice required previous bacterial microbiota reduction with antibiotics to be able to be colonized, removal of this procedure could take place the same day (or even before) Candida inoculation. This strain was able to colonize the intestine of mice already colonized with Candida without antibiotic treatment in co-housing experiments. CaORAL3 was also able to be established as a commensal in mice previously colonized by another (CaHG43) or the same (CaORAL3) C. albicans strain. Therefore, we have identified C. albicans isolates that display higher colonization load than the standard strain SC5314 which will surely facilitate the analysis of the factors that regulate fungal colonization.
Msb2 shedding protects Candida albicans against antimicrobial peptides
(Leah E. Cowen, University of Toronto, Canada, 2012-02-02) Szafranski-Schneider, Eva; Swidergall, Marc; Cottier, Fabien; Tielker, Denis; Román González, Elvira; Pla Alonso, Jesús; Ernst, Joachim F
Msb2 is a sensor protein in the plasma membrane of fungi. In the human fungal pathogen C. albicans Msb2 signals via the Cek1 MAP kinase pathway to maintain cell wall integrity and allow filamentous growth. Msb2 doubly epitope-tagged in its large extracellular and small cytoplasmic domain was efficiently cleaved during liquid and surface growth and the extracellular domain was almost quantitatively released into the growth medium. Msb2 cleavage was independent of proteases Sap9, Sap10 and Kex2. Secreted Msb2 was highly O-glycosylated by protein mannosyltransferases including Pmt1 resulting in an apparent molecular mass of >400 kDa. Deletion analyses revealed that the transmembrane region is required for Msb2 function, while the large N-terminal and the small cytoplasmic region function to downregulate Msb2 signaling or, respectively, allow its induction by tunicamycin. Purified extracellular Msb2 domain protected fungal and bacterial cells effectively from antimicrobial peptides (AMPs) histatin-5 and LL-37. AMP inactivation was not due to degradation but depended on the quantity and length of the Msb2 glycofragment. C. albicans msb2 mutants were supersensitive to LL-37 but not histatin-5, suggesting that secreted rather than cell-associated Msb2 determines AMP protection. Thus, in addition to its sensor function Msb2 has a second activity because shedding of its glycofragment generates AMP quorum resistance.