Bacterial Genetics
Research Lines
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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:
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Diagnosis and reference of HIV infection (types 1 and 2) through detection of specific antibodies and detection of proviral DNA by PCR.
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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
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- 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
Where are we with monoclonal antibodies for multidrug-resistant infections?
Where are we with monoclonal antibodies for multidrug-resistant infections? McConnell MJ. Drug Discov Today. 2019 May;24(5):1132-1138. doi: 10.1016/j.drudis.2019.03.002.
PUBMEDPeptidoglycan recycling contributes to intrinsic resistance to fosfomycin in Acinetobacter baumannii
Peptidoglycan recycling contributes to intrinsic resistance to fosfomycin in Acinetobacter baumannii. Gil-Marqués ML, Moreno-Martínez P, Costas C, Pachón J, Blázquez J, McConnell MJ. J Antimicrob Chemother. 2018 Nov 1;73(11):2960-2968. doi: 10.1093/jac/dky289.
PUBMEDImmunization with lipopolysaccharide-free outer membrane complexes protects against Acinetobacter baumannii infection
Immunization with lipopolysaccharide-free outer membrane complexes protects against Acinetobacter baumannii infection. Pulido MR, García-Quintanilla M, Pachón J, McConnell MJ. Vaccine. 2018 Jul 5;36(29):4153-4156. doi: 10.1016/j.vaccine.2018.05.113.
PUBMEDPhenotypic changes associated with Colistin resistance due to Lipopolysaccharide loss in Acinetobacter baumannii
Phenotypic changes associated with Colistin resistance due to Lipopolysaccharide loss in Acinetobacter baumannii. Carretero-Ledesma M, García-Quintanilla M, Martín-Peña R, Pulido MR, Pachón J, McConnell MJ. Virulence. 2018 Dec 31;9(1):930-942. doi: 10.1080/21505594.2018.1460187.
PUBMEDContent with Investigacion .
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Concepción Casado Herrero
Tenure Scientist of Public Research Organizations (OPIs)
ORCID code: 0000-0003-3412-2877
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María Pernas Escario
Senior Specialized Technician of Public Research Organizations (OPIs)
ORCID code: 0000-0003-2966-0160
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Virginia Sandonís Martín
Senior Specialized Technician of Public Research Organizations (OPIs)
ORCID code: 0000-0001-5762-7531
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Rosa Fuentes Fernández
Laboratory Technician
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.