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Mycobacteria

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.

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Publicaciones destacadas

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Carbapenemase-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 DOI

Balancing selection and the evolution of functional polymorphism in Old World monkey TRIM5alpha

Newman RM, Hall L, Connole M, Chen GL, Sato S, Yuste E, Diehl W, Hunter E, Kaur A, Miller GM, Johnson WE; Proc Natl Acad Sci U S A. 2006 Dec 12;103(50):19134-9

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High susceptibility to zoliflodacin and conserved target (GyrB) for zoliflodacin among 1209 consecutive clinical Neisseria gonorrhoeae isolates from 25 European countries, 2018.

Unemo M, Ahlstrand J, Sánchez-Busó L, Day M, Aanensen D, Golparian D, Jacobsson S, Cole MJ, Torreblanca RA, Ásmundsdóttir LR, Balla E, De Baetselier I, Bercot B, Carannante A, Caugant D, Borrego MJ, Buder S, Cassar R, Cole M, Dam A, Eder C, Hoffmann S, Hunjak B, Jeverica S, Kirjavainen V, Maikanti-Charalambous P, Miriagou V, Mlynarczyk-Bonikowska B, Pakarna G, Patterson L, Pavlik P, Perrin M, Shepherd J, Stefanelli P, Unemo M, Jelena V, Zákoucká H. J Antimicrob Chemother. 2021 Feb 10:dkab024

PUBMED DOI

Fluoroquinolone-resistant pneumococci: dynamics of serotypes and clones in Spain in 2012 compared with those from 2002 and 2006

Domenech A, Tirado-Vélez JM, Fenoll A, Ardanuy C, Yuste J, Liñares J, de la Campa AG. Antimicrob Agents Chemother. 58:2393-2399 (2014).

PUBMED DOI

DNGR-1+ dendritic cells are located in meningeal and choroid plexus membranes of the non-injured brain.

Quintana, E., Fernández. A, de Andrés, B., Liste, I., Sancho, D., Gaspar, ML. and Cano, E. Glia (2015) 62 (12):2231-2248

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Dissemination 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.

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Virion envelope content, infectivity, and neutralization sensitivity of simian immunodeficiency virus

Yuste E, Johnson W, Pavlakis GN, Desrosiers RC; J Virol. 2005 Oct;79(19):12455-63.

PUBMED DOI

Meningococcal Serogroup B Disease in Vaccinated Children

Soler-Garcia A, Fernández de Sevilla M, Abad R, Esteva C, Alsina L, Vázquez J, Muñoz-Almagro C, Noguera-Julian A. J Pediatric Infect Dis Soc. 2020 Sep 17;9(4):454-459

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Content with Investigacion Genética Bacteriana .

List of staff

Información adicional

• Taxonomic study. Objective: Association of already described species to new clinical processes. Description of new bacterial species. 

• Sensitivity studies against new antituberculous drugs: Objective: To evaluate the antimicrobial activity of new compounds for human use in clinical strains of Mycobacterium tuberculosis and in other species of non-tuberculous mycobacteria, for subsequent application in the treatment of these infections. 

• Molecular epidemiology of tuberculosis. Objectives: Molecular characterization of the members of the M. tuberculosis complex. Transmission studies with special surveillance of MDR/XDR tuberculosis. 

• Development of new methods of identification and detection of resistance in mycobacteria. Objectives: Optimization and development of molecular techniques for the diagnosis and detection of resistance.

Content with Investigacion Genética Bacteriana .