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Bacterial Genetics

Líneas de investigación

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Bacterial Genetics

Our group has been studying for more than 30 years the mechanisms of antibiotic resistance in Streptococcus pneumoniae (Spn). Our objectives are to understand the molecular basis of antimicrobial action, to search for new targets of action and new compounds. Seconeolitsine (SCN) is one of these new compounds targeting topoisomerase I (Topo I). As for the search for new targets, our research has focused in recent years on the factors that organize the topology of the chromosome, allowing optimal compaction (about 1000-fold) to harmonize its replication, chromosome segregation and gene expression. This compaction is mediated both by the level of DNA supercoiling (Sc) and by association with nucleoid-binding proteins (NAPs). The level of Sc depends mainly on the enzymatic activities of their DNA topoisomerases, reaching a homeostatic equilibrium by the opposite activities of the topoisomerases that relax DNA (Topo I and Topo IV), and of gyrase, which introduces negative Sc. Our group has characterized the three Spn topoisomerases and two NAPs: HU and SatR. In addition, the availability of antimicrobials that inhibit each of the Spn topoisomerases has allowed us to analyze their transcriptome under conditions of local or global change of the Sc level and to define gene domains of coordinated transcription and similar functions. Fluoroquinolones, which inhibit Topo IV and gyrase, produce local changes in Sc that induce alterations in 6% of the transcriptome, altering metabolic pathways that originate an increase in reactive oxygen species (ROS) that contribute to lethality, in accordance with the general mechanism of bactericidal antibiotics. On the other hand, the induction of global changes in Sc by novobiocin (NOV, gyrase inhibitor), or by SCN (Topo I inhibitor), has allowed us to define topological domains. Global changes in Sc include the regulation of topoisomerase genes: its decrease activates the transcription of gyrase genes (gyrA, gyrB) and inhibits those of Topo IV (parEC) and Topo I (topA); the increase in Sc regulates the expression of topA. Decreased Sc affects 37% of the genome, with >68% of genes clustered in 15 domains. Increased Sc affects 10% of the genome, with 25% of the genes clustered in 12 domains. The AT content in the genome correlates with the domains, being higher in UP domains than in DOWN domains. The genes in the different domains have common functional characteristics, indicating that they have been subjected to topological selective pressure to determine the location of genes involved in metabolism, virulence and competition. 

The current objectives of the group are:
1.    Identification of factors that stabilize chromosome topology: NAPs, ncRNAs, intra-chromosomal interactions.
2.    Regulation of transcription in response to topological stress: in vivo localization of DNA topoisomerases, RNA polymerase and NAPs.
3.    Topo I as a new antimicrobial target and action of SCN. 
4.    Design of antisense RNAs and use of the CRISPR system as new antibacterial agents.

Proyectos de investigación

Content with Investigacion Genética Bacteriana .

1) Project Title: Interaction Between DNA Supercoiling and Transcription in the Human Pathogen  Streptococcus pneumoniae

Principal Investigator:   Adela González de la Campa  
Funding Entity:   Ministry of Science and Innovation, State Research Agency (Call for "R&D&I Projects" 2020 – "Research Challenges" and "Knowledge Generation" Modalities).  
Reference:   PID2021-124738OB-100.  
Duration:   2022-2025.  
Funding Amount:   €108,900.
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2) Project Title:   Study of the Factors Organizing the Chromosome of  Streptococcus pneumoniae: New Antibiotic Targets and Resistance Mechanisms.

Principal Investigator:   Adela González de la Campa  
Funding Entity:   Ministry of Economy, Industry, and Competitiveness. State Research Agency.  
Reference:   BIO2017-82951-R.  
Duration:   2018-2020.  
Funding Amount:   €169,400.  

3) Project Title:   Role of DNA Topoisomerases and Nucleoid-Associated Proteins in the Chromosome Organization of  Streptococcus pneumoniae: Response to Antibiotics and Virulence.  

Principal Investigator:   Adela González de la Campa  
Funding Entity:   Ministry of Economy and Competitiveness. Secretariat of State for Research, Development, and Innovation.  
Reference:   BIO2014-55462.  
Duration:   2015-2017.  
Funding Amount:   €193,600.  

4) Project Title:   The Control of Supercoiling Level in  Streptococcus pneumoniae  as an Antimicrobial Target.  

Principal Investigator:   Adela González de la Campa  
Funding Entity:   Ministry of Economy and Competitiveness. Secretariat of State for Research, Development, and Innovation.  
Reference:   BIO2011-25343.  
Duration:   2012-2015.  
Funding Amount:   €209,000.  

5) Project Title:   Role of Small Non-Coding RNAs in the Pathogenicity of  Streptococcus pneumoniae.   

Principal Investigator:   Mónica Amblar Esteban  
Funding Entity:   Ministry of Economy and Competitiveness. Strategic Health Action (AES).  
Reference:   PI11/00656.  
Duration:   2012-2015.  
Funding Amount:   €198,714.
 

Publicaciones destacadas

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Obesity-related SNPs and weight gain following first-line antiretroviral therapy.

Berenguer J (*), Jarrín I, Bellón JM, Díez C, Jiménez-Sousa MA, Roca C, González-García J, Dalmau D, Olalla J, Herrero C, Villarroya F, Domingo P, Resino S. Obesity-related SNPs and weight gain following first-line antiretroviral therapy. Clin Inf Dis. 2023; In press. (A; FI= 20.99; D1, Infectious Diseases; JCR 2021).

PUBMED DOI

Mild profile improvement of immune biomarkers in HIV/HCV-coinfected patients who removed hepatitis C after HCV treatment: a prospective study.

García-Broncano P, Medrano LM, Berenguer J, Brochado O, González-García J, Jiménez-Sousa MA, Quereda C, Sanz J, Téllez MJ, Díaz L, Jiménez JL, Muñoz-Fernández MA, Resino S (*). Mild profile improvement of immune biomarkers in HIV/HCV-coinfected patients who removed hepatitis C after HCV treatment: a prospective study. J Infect 2020; 80(1):99-110. (A; FI= 6.07; Q1, Infectious Diseases; JCR 2020). PMID: 31585189. DOI: 10.1016/j.jinf.2019.09.020.

PUBMED

Evaluation of the possible influence of trailing and paradoxical effects on the clinical outcome of patients with candidemia

Rueda C, Puig-Asensio M, Guinea J, Almirante B, Cuenca-Estrella M, Zaragoza O; CANDIPOP Project from GEIH-GEMICOMED (SEIMC) and REIPI. Evaluation of the possible influence of trailing and paradoxical effects on the clinical outcome of patients with candidemia. Clin Microbiol Infect. 2017 Jan;23(1):49.e1-49.e8.

PUBMED DOI

Identification of Off-Patent Drugs That Show Synergism with Amphotericin B or That Present Antifungal Action against Cryptococcus neoformans and Candida spp

Rossi SA, de Oliveira HC, Agreda-Mellon D, Lucio J, Mendes-Giannini MJS, García-Cambero JP, Zaragoza O. Identification of Off-Patent Drugs That Show Synergism with Amphotericin B or That Present Antifungal Action against Cryptococcus neoformans and Candida spp. Antimicrob Agents Chemother. 2020 Mar 24;64(4):e01921-19. PMCID: PMC7179310.

PUBMED DOI

Content with Investigacion Genética Bacteriana .

List of staff

Información adicional

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.

The current director of CNM is Dr. José Miguel Rubio Muñoz.

Dr. José Miguel Rubio has a degree in Biological Sciences from the Universidad Autónoma de Madrid (1986) and a PhD in Biological Sciences from the same university (1992). He carried out his doctoral thesis at the Department of Genetics of the Universidad Autónoma de Madrid, as Associate Professor (1988-1989), and at the School of Biology of the University of East Anglia in Norwich, UK, as Senior Research Assistant (1989-1992).

During his postdoctoral period he obtained a grant from the European Commission within the Human Capital and Mobility Program to be carried out at the University of “La Sapienza” in Rome, Italy and the Institute of Molecular Biology and Biotechnology in Crete, Greece (1993-1994). Subsequently, he made a further stay funded by the WHO and the university itself at the Department of Entomology, Wageningen University, The Netherlands (1994-1996).

Since 1997 he has been a member of the Instituto de Salud Carlos III (ISCIII), where he joined the Department of Parasitology of the National Center of Microbiology, as an EU-INCO postdoctoral fellow and later with a grant from the Autonomous Community of Madrid (CAM). She was part of the founding group of the National Center for Tropical Medicine (2003-2006) and of the 24/7 Alerts and Emergencies Unit (2006-2018) and is currently Head of the Malaria and Emerging Parasitosis Unit of the National Microbiology Center and is part, as research staff, of the Center for Biomedical Research Network on Infectious Diseases (CIBERINFEC/ISCIII).

During his scientific career he has been Visiting Scientist at the Leonidas e Marie Dean Center (FIOCRUZ-AMAZONAS, Manaus, Brazil) and is an External Consultant of the Parasitology Departments of Cairo University (Egypt) and the Medical Research Center (MRC) of Kuala Lumpur (Malaysia).  He also belongs or has belonged to different national and international committees:  Member of the expert group for malaria control of the European Centre for Disease Control (ECDC) since 2011; Expert-Evaluator for health programs of the European Commission since 2004; Spanish Representative (commissioned by ISCIII and MSC) in the Technical Scientific Committee of the TDR (WHO) 2007-2008; Spanish Deputy Focal Point for microbiology at the European Centre for Disease Control (ECDC) from 2012 to 2020; and, member of the Research Ethics Committee of ISCIII until 2019.

In this period he has published more than 100 articles in international indexed journals, 10 book chapters and has been co-editor of two books in the area of malaria, tropical medicine and neglected diseases. He has participated in 58 competitively funded research projects, 20 of them international, having been the principal investigator in 8 national and 11 international projects as PI of the project or WP leader. In addition, he has led five agreements with companies. Currently he has been awarded four sexenios of research, being presented this year 2025 to the fifth. In the teaching field, he participates in different postgraduate programs in the areas of microbiology and parasitology, having directed seven doctoral theses and more than 20 Master's or Degree final projects, both nationally and internationally. ​​​​​

El laboratorio de Referencia e Investigación en Resistencia a Antibióticos ofrece una amplia cartera de servicios al Sistema Nacional de Salud, las cuales pueden solicitarse en cnm-laboratorios.isciii.es. Jefe del Laboratorio: Jesús Oteo Iglesias (Punto focal Nacional de Resistencia antibiótica).

Dispone de dos programas de Vigilancia oficiales y gratuitos que engloban los ensayos ofertados ya sea como aislamientos individuales o mediante estudio de brotes. El Laboratorio utiliza asimismo técnicas de PCR en tiempo real para la detección de genes de resistencia, estas técnicas se han adaptado a un formato multiplex que permite detectar varios genes en la misma reacción. En los últimos años se han incluido metodologías basadas en la secuenciación de genomas completos para el análisis de bacterias multiresistentes (WGS).

Programa de vigilancia de Haemophilus influenzae. Responsables: María Pérez Vázquez (Punto focal Nacional de Haemophilus influenzae) y Belén Aracil. Laboratorio encargado de la identificación, estudio de sensibilidad y análisis genotípico de aislados de Haemophilus influenzae, centrándose esencialmente en la patología invasiva debida este patógeno. 

Programa de vigilancia de Resistencia a Antibióticos. Responsables: María Pérez Vázquez  y Belén Aracil (Punto focal Nacional de Resistencia antibiótica). Laboratorio encargado de la identificación, el estudio de sensibilidad antibiótica, y el diagnóstico fenotípico y genotípico de los diferentes mecanismos de resistencia a antibióticos fundamentalmente en enterobacterias y gram-negativos no fermentadores y Enterococcus spp.

Estudio de brotes. Responsables: Belén Aracil y María Pérez Vázquez. El programa incluye la caracterización de brotes nosocomiales y clones emergentes de alto riesgo mediante diferentes técnicas moleculares (tabla resumen). Éstas, nos permiten realizar estudios filogenéticos con el fin de obtener una información detallada acerca la relación entre los diferentes aislados y su trazabilidad. El objetivo final es generar datos que se transfieren a los hospitales como ayuda para la prevención o control de la propagación del brote.

Acreditación y Calidad. Responsable: Belén Aracil. El laboratorio Referencia e Investigación en Resistencia a Antibióticos ha sido de los primeros en el ISCIII en la utilización de técnicas acreditadas por la Entidad Nacional de Acreditaciones (ENAC). Este laboratorio consiguió la primera acreditación homologada de técnicas diagnósticas en 2012, programa que ha sido ampliado, de manera que en la actualidad más de la mitad de las técnicas ofrecidas al Sistema Nacional de Salud están debidamente acreditadas por ENAC.

Técnicos responsables de las técnicas realizadas en el Laboratorio: Noelia Lara Fuella y Verónica Bautista Sánchez.

En la siguiente imagen se resumen las técnicas ofrecidas al Sistema Nacional de Salud.

PROGRAMAS NOMBRE CARTERA SERVICIO PATÓGENO DETERMINACIÓN, DETECCIÓN, ANÁLISIS MÉTODOS

Programa de vigilancia de Haemophilus

Programa de vigilancia de resistencia a antibióticos.

Identificación bacteriana

Haemophilus sp.

Enterobacterias, gram-negativos no fermentadores, Enterococcus spp

Identificación bacteriana

Bioquímicos

MALDI TOF

Secuenciación de RNAr

Identificación capsular

Haemophilus influenzae

 

Identificación capsular fenotípica y genotípica

Aglutinación serológica en latex

PCR ind/multiplex

Determinación de Sensibilidad

Haemophilus sp.

Enterobacterias, gram-negativos no fermentadores, Enterococcus

 

Determinación de Sensibilidad

Microdilución                

Tiras epsilon               

Kirby Bauer

Métodos fenotípicos de detección de mecanismos de resistencia

Enterobacterias, gram-negativos no fermentadores,

 

Métodos fenotípicos de detección de mecanismos de resistencia

Discos y tabletas combinados con inhibidores                

Tiras combinadas     

Test de Hodge modificado

CabaNP                               

Inmunocromatografía CBP

Métodos genotípicos de detección de mecanismos de resistencia

Haemophilus sp.

Enterobacterias, gram-negativos no fermentadores, Enterococcus

 

ADN, PCR y secuenciación

PCR ind/multiplex

Análisis comparativo de las secuencias

Tipificación molecular/análisis filogenéticos

Haemophilus sp.

Enterobacterias, gram-negativos no fermentadores, Enterococcus

 

Corte enzimas de restricción, electroforesis

ADN, PCR y secuenciación

Preparación de librerías y secuenciación y análisis de genomas completos

 

PFGE

 

MLST

 

WGS