Toxoplasmosis and intestinal protozoa
Research Lines
Content with Investigacion .
Research
The Molecular Virology group focuses its research on the study of HIV-1 genetic variation and viral evolution using both in vitro and ex vivo approaches, structured around the following research lines:
- Non-progressor patients. These patients maintain control of the disease in the absence of antiretroviral therapy and have therefore been proposed as a model of functional cure. Our objective is to study the contribution of viral factors to disease control through biological characterization and analysis of viral evolution in individuals with undetectable viral loads (elite controllers, EC), compared with individuals showing other patterns of viral control.
- Viral envelope. This viral protein is key in determining viral fitness. Therefore, its functionality significantly affects infection progression. In collaboration with Dr. Blanco and Dr. Valenzuela, we study which specific events (CD4 binding, fusogenicity, etc.) are associated with envelope functionality. To this end, we have analyzed envelopes from individuals with different patterns of disease progression. Some of these have been contributed to the AIDS Research Network envelope biobank for broader use.
- Dual infection. Infection with more than one viral variant (either through co-infection or superinfection) may have consequences for infection pathogenesis. Within our group, different aspects of DI have been analyzed, including its detection in non-progressor patients, its prevalence and incidence in Spain, and its influence on the neutralizing antibody response.
- Molecular Epidemiology. The group has analyzed viral evolution throughout the epidemic in Spain and in other countries (the Netherlands, Italy, Germany, Uruguay, Panama, Brazil, etc.).
- Role of amino acid residues in reverse transcriptase. We study the role of specific amino acid residues in HIV-1 reverse transcriptase in enzymatic function and replication capacity using an infectious molecular clone previously obtained by the group.
- “In vitro” variability. Serial passage studies have been used to detect the mechanisms responsible for the gain or loss of viral fitness.
- Antiviral studies. We have analyzed the selection of resistance mutations in vitro against different antivirals, as well as the effect of these mutations on viral fitness, and the activity of new antivirals such as ATR inhibitors.
Virological Diagnosis and Reference in HIV and HTLV Infections
The research group provides diagnostic and reference activities through the service portfolio of the National Center for Microbiology to the entire Spanish National Health System.
These services include:
-
Diagnosis and reference of HIV infection (types 1 and 2) through detection of specific antibodies and detection of proviral DNA by PCR.
-
Diagnosis and reference of HTLV-I/II infection through detection of specific antibodies and detection of proviral DNA by PCR. Quantification of HTLV-1 proviral load by real-time PCR.
European Union Reference Laboratory (EURL) in the field of in vitro diagnostic medical devices for microbiological diagnosis (IVD) of HIV and HTLV (Regulation 2023/2713 of December 5th, 2023). Our role is to confirm the reliability and effectiveness of devices for detecting these pathogens and to ensure their specific performance requirements through laboratory testing before they can be marketed within the European Union.
Research projects
Content with Investigacion .
- Towards a functional cure: Implications of early antiretroviral therapy and hormonal changes on the HIV reservoir in perinatally infected adolescents. Health Research Fund (FIS) – Carlos III Health Institute (01/01/2026 – 31/12/2028). €72,000. PI: María Pernas, Concepción Casado.
- Determination of factors associated with protection against Human Immunodeficiency Virus type 1 reinfection: Identification of correlates of protection. 9th Gilead Fellowship Program for Biomedical Research, Gilead Sciences, S.L. (01/07/2023 – 30/06/2025). €16,330. PI: María Pernas.
- Impact of the envelope on HIV viral replication: New avenues for vaccine development. Health Research Fund (FIS) – Carlos III Health Institute (01/01/2020 – 31/12/2023). €53,000. PI: María Pernas, Concepción Casado.
- Study of HIV-1 virulence in recently infected patients and its contribution, together with clinical and epidemiological factors, to disease progression. Ministry of Economy and Competitiveness. State Program for Scientific and Technical Research and Innovation (30/12/2016 – 30/06/2021). €145,000. PI: Concepción Casado, Cecilio López-Galíndez.
-Contribution of HIV-1 dual infection to virological and clinical evolution in homo/bisexual men. Health Research Fund (FIS) – Carlos III Health Institute (01/01/2014 – 31/01/2016). €74,410. PI: Cecilio López-Galíndez.
- Characterization of non-pathogenic HIV variants obtained “ex vivo” and “in vitro” for the study of disease pathogenesis. Ministry of Science and Innovation (01/01/2011 – 31/01/2014). €169,400. PI: Cecilio López-Galíndez.
- Spanish AIDS Research Network (RIS-RETIC). Carlos III Health Institute (02/01/2017 – 02/01/2022). €195,212. PI: Cecilio López-Galíndez, Concepción Casado.
Publications
Biased binding of class IA phosphatidyl inositol 3-kinase subunits to inducible costimulator (CD278)
8. Acosta Y.Y., Zafra M.P., Ojeda G., Bernardone I.S., Dianzani U., Portolés P., Rojo J.M. Biased binding of class IA phosphatidyl inositol 3-kinase subunits to inducible costimulator (CD278). Cell. Mol. Life Sci. 2011 Sep;68(18):3065-79.
PUBMED DOIStructure and Immunogenicity of the Human Metapneumovirus F Protein in the Postfusion Conformation.
5. Mas V, Rodriguez L, Olmedillas E, Cano O, Palomo C, Terron MC, et al. Engineering, Structure and Immunogenicity of the Human Metapneumovirus F Protein in the Postfusion Conformation. PLoS Pathog. 2016;12(9):e1005859.
PUBMED DOIEssential in vitro diagnostics for advanced HIV and serious fungal diseases: international experts' consensus recommendations. Eur J Clin Microbiol Infect Dis. 2019 Sep
Bongomin F, Govender NP, Chakrabarti A, Robert-Gangneux F, Boulware DR, Zafar A, Oladele RO, Richardson MD, Gangneux JP, Alastruey-Izquierdo A, Bazira J, Boyles TH, Sarcarlal J, Nacher M, Obayashi T, Worodria W, Pasqualotto AC, Meya DB, Cheng B, Sriruttan C, Muzoora C, Kambugu A, Rodriguez Tudela JL, Jordan A, Chiller TM, Denning DW. Essential in vitro diagnostics for advanced HIV and serious fungal diseases: international experts' consensus recommendations. Eur J Clin Microbiol Infect Dis. 2019 Sep;38(9):1581-1584. doi: 10.1007/s10096-019-03600-4. PMID: 31175479.
PUBMED DOIGodet C, Alastruey-Izquierdo A, Flick H, Hennequin C, Mikilps-Mikgelbs R, Munteanu O, Page I, Seidel D, Salzer HJF. A CPAnet consensus statement on research priorities for chronic pulmonary aspergillosis: a neglected fungal infection that requires attention. J Antimicrob Chemother. 2018
Godet C, Alastruey-Izquierdo A, Flick H, Hennequin C, Mikilps-Mikgelbs R, Munteanu O, Page I, Seidel D, Salzer HJF. A CPAnet consensus statement on research priorities for chronic pulmonary aspergillosis: a neglected fungal infection that requires attention. J Antimicrob Chemother. 2018 Feb 1;73(2):280-286. doi: 10.1093/jac/dkx390. PMID: 29126309.
PUBMED DOIContent with Investigacion .
-
-
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
Our group carries out research studies in the diagnosis, reference and epidemiology of zoonoses and emerging diseases, both indigenous and imported, caused by protozoa. Coordinates the study in the human field with the relevance of the animal field and the environment (One Health initiative), with special interest in Toxoplasmosis, a highly prevalent zoonosis (WHO lists it as the 3rd food-borne zoonosis in Europe), presents a complex epidemiological cycle and causes neurological, ocular and systemic symptoms. We carry out diagnostic and characterization studies of Toxoplasma gondii from human and animal cases, to obtain greater epidemiological information and analyze the possible relationship with virulence and pathology.
Cryptosporidium, Giardia, Blastocystis and Entamoeba histolytica cause gastrointestinal diseases, affecting children, immunosuppressed people and travelers. They can cause outbreaks. We develop diagnostic and characterization studies of isolates from humans and animals, from different areas and countries, to establish the presence of the main species and genotypes and the epidemiological situation. We are beginning the study of associations between these parasites and the intestinal microbiota.
The pathogenic Free-Living Amoebas, Acanthamoeba, Naegleria fowleri and Balamuthia mandrillaris, cause emerging diseases, highlighting the importance of the environment in transmission. They cause underdiagnosed neurological and ocular cases. The diagnostic and genotyping study of human and animal isolates that we are carrying out aims to establish the real prevalence, transmission routes and epidemiology.
Our group carries out research studies in the diagnosis, reference and epidemiology of zoonoses and emerging diseases, both indigenous and imported, caused by protozoa. Coordinates the study in the human field with the relevance of the animal field and the environment (One Health initiative), with special interest in Toxoplasmosis, a highly prevalent zoonosis (WHO lists it as the 3rd food-borne zoonosis in Europe), presents a complex epidemiological cycle and causes neurological, ocular and systemic symptoms. We carry out diagnostic and characterization studies of Toxoplasma gondii from human and animal cases, to obtain greater epidemiological information and analyze the possible relationship with virulence and pathology.
Cryptosporidium, Giardia, Blastocystis and Entamoeba histolytica cause gastrointestinal diseases, affecting children, immunosuppressed people and travelers. They can cause outbreaks. We develop diagnostic and characterization studies of isolates from humans and animals, from different areas and countries, to establish the presence of the main species and genotypes and the epidemiological situation. We are beginning the study of associations between these parasites and the intestinal microbiota.
The pathogenic Free-Living Amoebas, Acanthamoeba, Naegleria fowleri and Balamuthia mandrillaris, cause emerging diseases, highlighting the importance of the environment in transmission. They cause underdiagnosed neurological and ocular cases. The diagnostic and genotyping study of human and animal isolates that we are carrying out aims to establish the real prevalence, transmission routes and epidemiology.