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Susceptibilidad del huésped a las infecciones fúngicas invasoras
Se estima que más de un millón y medio de personas mueren al año en el mundo debido a una enfermedad fúngica invasora (EFI). Los tratamientos con inmunosupresores, terapias con corticoides, trasplantes de células hematopoyéticas y órgano sólido así como tratamientos quimioterapéuticos contra el cáncer han favorecido el aumento de estas infecciones fúngicas. El género Aspergillus es la principal causa de EFI por hongos filamentosos, siendo A. fumigatus la especie principalmente aislada en la mayoría de los casos y más frecuentemente asociada a Aspergilosis Invasora.
Muchas de estas infecciones están infra-diagnosticadas debido, tanto a la falta de sospecha clínica como a las limitaciones diagnósticas. Esta línea de investigación tiene como principal objetivo mejorar el pronóstico de la infecciones en pacientes con riesgo de desarrollar infecciones invasoras por hongos. Para ello se estudian marcadores del individuo (denominados biomarcadores del hospedador) que puedan ser detectados de forme temprana en muestras de pacientes en riesgo y que nos permita estratificar a los mismos en función de la susceptibilidad a desarrollar una infección invasora por hongos. Además, estudios realizados en los últimos años muestran que el fondo genético del hospedador está asociado con la predisposición al desarrollo de este tipo de enfermedades. En concreto se han identificado polimorfismos genéticos de nucleótido simple (“Single Nucleotide Polymorphism”- SNP) en genes que codifican para componentes celulares que interaccionan con estructuras fúngicas y/o que están involucradas en la respuesta inmune del huésped frente a agentes infecciosos como Aspergillus. En este sentido se han estandarizado y aplicado herramientas para la detección de SNPs en humanos de genes diana asociados concretamente con la susceptibilidad a la Aspergilosis Invasora.
Estudio de los mecanismos de virulencia en Aspergillus fumigatus
En paralelo al estudio de la respuesta del hospedador se sigue una línea cuyo objetivo es caracterizar mecanismos de virulencia en A. fumigatus. Uno de los principales mecanismos por los que A. fumigatus es capaz de causar enfermedad en humanos es su capacidad de adaptarse a las condiciones ambientales del hospedador. Entre las moléculas y los genes que se han relacionado con la virulencia de este hongo se encuentran componentes de la pared celular, genes y moléculas relacionadas con la evasión de la respuesta inmune, sistemas de detoxificación de los compuestos derivados del oxígeno, la producción de toxinas, la obtención de nutrientes como hierro, fósforo, nitrógeno y la adaptación a pH y temperatura del hospedador. Estos estudios permiten profundizar en el conocimiento sobre la patogenicidad de este hongo e identificar nuevas dianas terapéuticas
Publications
Hypervirulent Klebsiella pneumoniae: Epidemiology outside Asian countries, antibiotic resistance association, methods of detection and clinical management
12. Hypervirulent Klebsiella pneumoniae: Epidemiology outside Asian countries, antibiotic resistance association, methods of detection and clinical management. Autores: García-Cobos S, Oteo-Iglesias J, Pérez-Vázquez M. Revista: Enferm Infecc Microbiol Clin (Engl Ed). 2025 Feb;43(2):102-109.
PUBMED DOIRapid cross-border emergence of NDM-5-producing Escherichia coli in the European Union/European Economic Area, 2012 to June 2022
15. Rapid cross-border emergence of NDM-5-producing Escherichia coli in the European Union/European Economic Area, 2012 to June 2022. Autores: Linkevicius M, Bonnin RA, Alm E, Svartström O, Apfalter P, Hartl R, Hasman H, Roer L, Räisänen K, Dortet L, Pfennigwerth N, Hans JB, Tóth Á, Buzgó L, Cormican M, Delappe N, Monaco M, Giufrè M, Hendrickx AP, Samuelsen Ø, Pöntinen AK, Caniça M, Manageiro V, Oteo-Iglesias J, Pérez-Vázquez M, Westmo K, Mäkitalo B, Palm D, Monnet DL, Kohlenberg A. Revista: Euro Surveill. 2023 May;28(19):2300209.
PUBMED DOICharacterization of Carbapenemase-Producing Klebsiella oxytoca in Spain, 2016-2017.
18. Characterization of Carbapenemase-Producing Klebsiella oxytoca in Spain, 2016-2017. Autores: Pérez-Vazquez M, Oteo-Iglesias J, Sola-Campoy PJ, Carrizo-Manzoni H, Bautista V, Lara N, Aracil B, Alhambra A, Martínez-Martínez L, Campos J; Spanish Antibiotic Resistance Surveillance Program Collaborating Group. Revista: Antimicrob Agents Chemother. 2019 May 24;63(6): e02529-18.
PUBMED DOICarbapenemase-Producing Klebsiella pneumoniae From Transplanted Patients in Brazil: Phylogeny, Resistome, Virulome and Mobile Genetic Elements Harboring blaKPC-2 or blaNDM-1.
16. Carbapenemase-Producing Klebsiella pneumoniae From Transplanted Patients in Brazil: Phylogeny, Resistome, Virulome and Mobile Genetic Elements Harboring blaKPC-2 or blaNDM-1. Autores: Raro OHF, da Silva RMC, Filho EMR, Sukiennik TCT, Stadnik C, Dias CAG, Oteo Iglesias J, Pérez-Vázquez M. Revista: Front Microbiol. 2020 Jul 15;11:1563.
PUBMED DOIDissemination of extensively drug-resistant NDM-producing Providencia stuartii in Europe linked to patients transferred from Ukraine, March 2022 to March 2023
17. Dissemination of extensively drug-resistant NDM-producing Providencia stuartii in Europe linked to patients transferred from Ukraine, March 2022 to March 2023. Autores: Witteveen S, Hans JB, Izdebski R, Hasman H, Samuelsen Ø, Dortet L, Pfeifer Y, Delappe N, Oteo-Iglesias J, Żabicka D, Cormican M, Sandfort M, Reichert F, Pöntinen AK, Fischer MA, Verkaik N, Pérez-Vazquez M, Pfennigwerth N, Hammerum AM, Hallstrøm S, Biedrzycka M, Räisänen K, Wielders CC, Urbanowicz P, de Haan A, Westmo K, Landman F, van der Heide HG, Lansu S, Zwittink RD, Notermans DW, Guzek A, Kondratiuk V, Salmanov A, Haller S, Linkevicius M, Gatermann S, Kohlenberg A, Gniadkowski M, Werner G, Hendrickx AP. Revista: Euro Surveill. 2024 Jun;29(23):2300616.
PUBMED DOISpread of the FAR-MRSA clone, a fusidic acid- and meticillin-resistant Staphylococcus aureus ST121, Europe, 2014 to 2024.
19. Spread of the FAR-MRSA clone, a fusidic acid- and meticillin-resistant Staphylococcus aureus ST121, Europe, 2014 to 2024. Autores: Roer L, Yin N, Denis O, Vendrik KE, Zwittink RD, Notermans DW, Perrin M, Khonyongwa K, Tristan A, Youenou B, Layer-Nicolaou F, Werner G, Enger H, Eikrem ECH, Darenberg J, Mäkitalo B, Paulsson M, Björkman J, Fang H, Hallbäck ET, Sundqvist M, Lindholm L, Moganeradj K, García-Cobos S, Cañada-García JE, Holzknecht BJ, Eriksen HB, Hoppe M, Bartels MD, Samaniego Castruita JA, Urth TR, Larsen AR, Petersen A. Revista: Euro Surveill. 2025 Jul;30(28):2500452.
DOICarbapenemase-producing Emergence of NDM-producing Klebsiella pneumoniae and Escherichia coli in Spain: phylogeny, resistome, virulence and plasmids encoding blaNDM-like genes as determined by WGS. aeruginosa in Spain: interregional dissemination of the high risk-clones ST175 and ST244 carrying blaVIM-2, blaVIM-1, blaIMP-8, blaVIM-20 and blaKPC-2
14. Emergence of NDM-producing Klebsiella pneumoniae and Escherichia coli in Spain: phylogeny, resistome, virulence and plasmids encoding blaNDM-like genes as determined by WGS. Autores: Pérez-Vázquez M, Sola Campoy PJ, Ortega A, Bautista V, Monzón S, Ruiz-Carrascoso G, Mingorance J, González-Barberá EM, Gimeno C, Aracil B, Sáez D, Lara N, Fernández S, González-López JJ, Campos J, Kingsley RA, Dougan G, Oteo-Iglesias J; Spanish NDM Study Group. Revista: J Antimicrob Chemother. 2019 Dec 1;74(12):3489-3496.
PUBMED DOIContent with Investigacion .
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Leticia Bernal Martínez
Staff Scientist
ORCID code: 0000-0002-1694-5522
Dr. Bernal-Martínez obtained her degree in Biochemistry from the University of Zaragoza in 2005. She joined the Mycology Reference and Research Laboratory (LRIM) in 2006 under a trainee contract and completed her PhD within the Official Doctoral Program in Microbiology and Parasitology at the Complutense University of Madrid, defending her thesis in 2010 with highest honors (Cum Laude). In 2007, she continued her research activity at LRIM within the framework of the Spanish Network for Research in Infectious Diseases (REIPI). In 2016, she completed a Postgraduate Diploma in Promotion and Management of International Projects (Technical University of Madrid) and undertook a research stay at the Microbiology and Infection Research Domain, Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho (Braga, Portugal). She was subsequently appointed as a PhD researcher within the Biomedical Research Networking Center in Infectious Diseases (CIBERINFEC). Since 2024, she serves as Specialist Scientist at the Carlos III Health Institute (ISCIII) and is responsible for the Diagnostic and Serology Section for Endemic Fungi at the Mycology Reference and Research Laboratory.
Dr. Bernal-Martínez has authored more than 30 peer-reviewed scientific publications and two book chapters. She has actively participated in over 12 research projects and has presented her work at numerous national and international scientific conferences. Her research has focused on human fungal infections, antifungal resistance, therapeutic drug monitoring, genetic variants associated with antifungal metabolism, and the identification of predictive biomarkers of invasive fungal infections. However, her primary expertise lies in the diagnostic field, particularly in the design, optimization, and validation of real-time PCR–based methodologies.
She is currently Principal Investigator of a research project aimed at improving current diagnostic techniques for invasive fungal infections, evaluating emerging diagnostic technologies, and studying primary fungal pathogens. A substantial part of her work has been transferred to the Spanish National Health System and to research centers in Latin America. Many of the diagnostic methodologies developed have been incorporated into the official service portfolio of ISCIII. She has collaborated with multiple hospitals through research projects and clinical trials applying these technologies, as well as with the ISCIII spin-off company Micomol S.L.
Dr. Bernal-Martínez has supervised several Master’s and Undergraduate Final Degree Projects from students at the Complutense University of Madrid and the University of Alcalá. She is a member of the teaching staff of the UNED-ISCIII PhD Program in Biomedical Sciences and Public Health and serves as lecturer in the Master’s Program in Public Health and Research in Infectious Diseases at the University of Alcalá. -
Laura Alcázar Fuoli
Research Scientist
Graduated in Biochemistry from the Autonomous University of Madrid and PhD in Biology from the Complutense University of Madrid in 2006. She completed her doctoral thesis at the National Center of Microbiology (CNM) under the direction of Dr. Emilia Mellado, in the study of the synthesis of Ergosterol in Aspergillus fumigatus. In 2012 Laura joined the reference laboratory in mycology with a researcher contract for the “Miguel Servet” program after having worked for three years as an associate researcher at Imperial College London. During that period his research focused on host adaptation mechanisms and virulence factors of A. fumigatus. In 2014 he obtained the position of Senior Scientist of Public Research Organizations carrying out his research work at the CNM.
List of staff
Additional Information
Streptococcus pneumoniae is a human pathogen that, despite the development of vaccines, continues to be an important cause of mortality and morbidity. We investigate the mechanisms of antibiotic resistance in this bacterium. On the one hand by identifying new therapeutic targets and on the other hand by investigating the molecular basis of the action of antibiotics already used in clinical practice (the fluoroquinolones levofloxacin and moxifloxacin) or not yet used (seconeolitsine). For this purpose, we used a multidisciplinary analysis involving genomics, transcriptomics and proteomics to understand the organization of the S. pneumoniae chromosome and the identification of the factors that stabilize this organization, including ncRNAs. Changes in the level of global supercoiling, either by inhibition of gyrase (decrease) or by inhibition of topoisomerase I (increase) alter the transcriptome. The modulated genes are located in domains, whose genes show specific functional characteristics. The aim is to identify new factors essential for S. pneumoniae physiology and to characterize transcriptional regulation in response to topological stress. In addition, RNA interference technology and CRISPR systems will be used as novel antibacterials. These studies will establish the bases for translational research aimed at the development of new therapeutic targets for the treatment of pneumococcal diseases.
Streptococcus pneumoniae is a human pathogen that, despite the development of vaccines, continues to be an important cause of mortality and morbidity. We investigate the mechanisms of antibiotic resistance in this bacterium. On the one hand by identifying new therapeutic targets and on the other hand by investigating the molecular basis of the action of antibiotics already used in clinical practice (the fluoroquinolones levofloxacin and moxifloxacin) or not yet used (seconeolitsine). For this purpose, we used a multidisciplinary analysis involving genomics, transcriptomics and proteomics to understand the organization of the S. pneumoniae chromosome and the identification of the factors that stabilize this organization, including ncRNAs. Changes in the level of global supercoiling, either by inhibition of gyrase (decrease) or by inhibition of topoisomerase I (increase) alter the transcriptome. The modulated genes are located in domains, whose genes show specific functional characteristics. The aim is to identify new factors essential for S. pneumoniae physiology and to characterize transcriptional regulation in response to topological stress. In addition, RNA interference technology and CRISPR systems will be used as novel antibacterials. These studies will establish the bases for translational research aimed at the development of new therapeutic targets for the treatment of pneumococcal diseases.