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Mycobacteria

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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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Role of Neutralizing Antibodies in CMV Infection: Implications for New Therapeutic Approaches

Role of Neutralizing Antibodies in CMV Infection: Implications for New Therapeutic Approaches. Sandonís V, García-Ríos E, McConnell MJ, Pérez-Romero P.Sandonís V, et al. Trends Microbiol. 2020 Nov;28(11):900-912. doi: 10.1016/j.tim.2020.04.003. PMID: 32448762 Review.

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Pre-existing Hemagglutinin Stalk Antibodies Correlate with Protection of Lower Respiratory Symptoms in Flu-Infected Transplant Patients

Pre-existing Hemagglutinin Stalk Antibodies Correlate with Protection of Lower Respiratory Symptoms in Flu-Infected Transplant Patients. Aydillo T, Escalera A, Strohmeier S, Aslam S, Sanchez-Cespedes J, Ayllon J, Roca-Oporto C, Pérez-Romero P, Montejo M, Gavalda J, Munoz P, Lopez-Medrano F, Carratala J, Krammer F, García-Sastre A, Cordero E. Cell Rep Med. 2020 Nov 3;1(8):100130. doi: 10.1016/j.xcrm.2020.100130. PMID: 33294855

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Effect of Influenza Vaccination Inducing Antibody Mediated Rejection in Solid Organ Transplant Recipients. Cordero E, Bulnes-Ramos A, Aguilar-Guisado M, González Escribano F, Olivas I, Torre-Cisneros J, Gavaldá J, Aydillo T, Moreno A, Montejo M, Fariñas MC, Carratalá J, Muñoz P, Blanes M, Fortún J, Suárez-Benjumea A, López-Medrano F, Roca C, Lara R, Pérez-Romero P. Front Immunol. 2020 Oct 6;11:1917. doi: 10.3389/fimmu.2020.01917. PMID: 33123119

Effect of Influenza Vaccination Inducing Antibody Mediated Rejection in Solid Organ Transplant Recipients. Cordero E, Bulnes-Ramos A, Aguilar-Guisado M, González Escribano F, Olivas I, Torre-Cisneros J, Gavaldá J, Aydillo T, Moreno A, Montejo M, Fariñas MC, Carratalá J, Muñoz P, Blanes M, Fortún J, Suárez-Benjumea A, López-Medrano F, Roca C, Lara R, Pérez-Romero P. Front Immunol. 2020 Oct 6;11:1917. doi: 10.3389/fimmu.2020.01917. PMID: 33123119

Humoral response to natural influenza infection in solid organ transplant recipients

Humoral response to natural influenza infection in solid organ transplant recipients. Hirzel C, Ferreira VH, L'Huillier AG, Hoschler K, Cordero E, Limaye AP, Englund JA, Reid G, Humar A, Kumar D; Influenza in Transplant Study Group.Hirzel C, et al. Am J Transplant. 2019 Aug;19(8):2318-2328. doi: 10.1111/ajt.15296. Epub 2019 Mar 18.Am J Transplant. 2019. PMID: 30748090 Clinical Trial.

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A 5-Year Prospective Multicenter Evaluation of Influenza Infection in Transplant Recipients

A 5-Year Prospective Multicenter Evaluation of Influenza Infection in Transplant Recipients. Kumar D, Ferreira VH, Blumberg E, Silveira F, Cordero E, Perez-Romero P, Aydillo T, Danziger-Isakov L, Limaye AP, Carratala J, Munoz P, Montejo M, Lopez-Medrano F, Farinas MC, Gavalda J, Moreno A, Levi M, Fortun J, Torre-Cisneros J, Englund JA, Natori Y, Husain S, Reid G, Sharma TS, Humar A.Kumar D, et al. Clin Infect Dis. 2018 Oct 15;67(9):1322-1329. doi: 10.1093/cid/ciy294.Clin Infect Dis. 2018. PMID: 29635437 Clinical Trial.

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Impact of pretransplant CMV-specific T-cell immune response in the control of CMV infection after solid organ transplantation: a prospective cohort study

Impact of pretransplant CMV-specific T-cell immune response in the control of CMV infection after solid organ transplantation: a prospective cohort study. Molina-Ortega A, Martín-Gandul C, Mena-Romo JD, Rodríguez-Hernández MJ, Suñer M, Bernal C, Sánchez M, Sánchez-Céspedes J, Pérez Romero P, Cordero E.Molina-Ortega A, et al. Clin Microbiol Infect. 2019 Jun;25(6):753-758. doi: 10.1016/j.cmi.2018.09.019. PMID: 30292792 Clinical Trial.

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Two Doses of Inactivated Influenza Vaccine Improve Immune Response in Solid Organ Transplant Recipients: Results of TRANSGRIPE 1-2, a Randomized Controlled Clinical Trial.

Two Doses of Inactivated Influenza Vaccine Improve Immune Response in Solid Organ Transplant Recipients: Results of TRANSGRIPE 1-2, a Randomized Controlled Clinical Trial. Cordero E, Roca-Oporto C, Bulnes-Ramos A, Aydillo T, Gavaldà J, Moreno A, Torre-Cisneros J, Montejo JM, Fortun J, Muñoz P, Sabé N, Fariñas MC, Blanes-Julia M, López-Medrano F, Suárez-Benjumea A, Martinez-Atienza J, Rosso-Fernández C, Pérez-Romero P. Clin Infect Dis. 2017 Apr 1;64(7):829-838. doi: 10.1093/cid/ciw855.Clin Infect Dis. 2017. PMID: 28362949 Clinical Trial.

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Use of antibodies neutralizing epithelial cell infection to diagnose patients at risk for CMV Disease after transplantation

Use of antibodies neutralizing epithelial cell infection to diagnose patients at risk for CMV Disease after transplantation. Blanco-Lobo P, Cordero E, Martín-Gandul C, Gentil MA, Suárez-Artacho G, Sobrino M, Aznar J, Pérez-Romero P.Blanco-Lobo P, et al. J Infect. 2016 May;72(5):597-607. doi: 10.1016/j.jinf.2016.02.008. Epub 2016 Feb 24.J Infect. 2016. PMID: 26920791 Clinical Trial.

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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 .