IMPLICACION DE FUNCIONES DEL HUESPED, FACTORES DE VIRULENCIA BACTERIANOS, E INTERFERENCIA TERAPEUTICA EN LA INFECCION POR EL PATOGENO RESPIRATORIO HAEMOPHILUS INFLUENZAE

SAF2012-31166

Nombre agencia financiadora Ministerio de Economía y Competitividad
Acrónimo agencia financiadora MINECO
Programa Programa Nacional de Investigación Fundamental
Subprograma Investigación fundamental no-orientada
Convocatoria Proyectos de Investigación Fundamental No-Orientada
Año convocatoria 2012
Unidad de gestión Dirección General de Investigación Científica y Técnica
Centro beneficiario AGENCIA ESTATAL CONSEJO SUPERIOR DE INVESTIGACIONES CIENTIFICAS (CSIC)
Centro realización INSTITUTO DE AGROBIOTECNOLOGÍA (Centro Mixto GN-UPNA)
Identificador persistente http://dx.doi.org/10.13039/501100003329

Publicaciones

Found(s) 5 result(s)
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Genome expression profiling-based identification and administration efficacy of host-directed antimicrobial drugs against respiratory infection by nontypeable Haemophilus influenzae

Digital.CSIC. Repositorio Institucional del CSIC
  • Euba, Begoña
  • Moleres, Javier
  • Segura, Víctor
  • Viadas, Cristina
  • Morey, Pau
  • Moranta, David
  • Leiva, José
  • de-Torres, Juan Pablo
  • Bengoechea, José Antonio
  • Garmendia, Juncal
Therapies that are safe, effective, and not vulnerable to developing resistance are highly desirable to counteract bacterial infections. Host-directed therapeutics is an antimicrobial approach alternative to conventional antibiotics based on perturbing host pathways subverted by pathogens during their life cycle by using host-directed drugs. In this study, we identified and evaluated the efficacy of a panel of host-directed drugs against respiratory infection by nontypeable Haemophilus influenzae (NTHi). NTHi is an opportunistic pathogen that is an important cause of exacerbation of chronic obstructive pulmonary disease (COPD). We screened for host genes differentially expressed upon infection by the clinical isolate NTHi375 by analyzing cell whole-genome expression profiling and identified a repertoire of host target candidates that were pharmacologically modulated. Based on the proposed relationship between NTHi intracellular location and persistence, we hypothesized that drugs perturbing host pathways used by NTHi to enter epithelial cells could have antimicrobial potential against NTHi infection. Interfering drugs were tested for their effects on bacterial and cellular viability, on NTHi-epithelial cell interplay, and on mouse pulmonary infection. Glucocorticoids and statins lacked in vitro and/or in vivo efficacy. Conversely, the sirtuin-1 activator resveratrol showed a bactericidal effect against NTHi, and the PDE4 inhibitor rolipram showed therapeutic efficacy by lowering NTHi375 counts intracellularly and in the lungs of infected mice. PDE4 inhibition is currently prescribed in COPD, and resveratrol is an attractive geroprotector for COPD treatment. Together, these results expand our knowledge of NTHi-triggered host subversion and frame the antimicrobial potential of rolipram and resveratrol against NTHi respiratory infection., J.M. is funded by Ph.D. studentship BES-2013-062644 from the Ministerio Economía y Competitividad-MINECO, Spain. This study was funded by grants from ISCIII (PS09/00130), the Ministerio Economía y Competitividad (MINECO SAF2012-31166), and the Departamento de Salud Gobierno Navarra (359/2012) to J.G. CIBERES is an initiative from ISCIII, Spain., Peer Reviewed




Modulation of Haemophilus influenzae interaction with hydrophobic molecules by the VacJ/MlaA lipoprotein impacts strongly on its interplay with the airways

Dadun. Depósito Académico Digital de la Universidad de Navarra
  • Fernández-Calvet, A. (Ariadna)
  • Rodríguez-Arce, I. (Irene)
  • Almagro, G. (Goizeder)
  • Moleres, J. (Javier)
  • Euba, B. (Begoña)
  • Caballero, L. (Lucía)
  • Martí, S. (Sara)
  • Ramos-Vivas, J. (Jose)
  • Leigh-Bartholomew, T. (Toby)
  • Morales-Urteaga, X. (Xabier)
  • Ortiz-de-Solorzano, C. (Carlos)
  • Yuste, J.E. (José Enrique)
  • Bengoechea, J.A. (José A.)
  • Conde-Alvarez, R. (Raquel)
  • Garmendia, J. (Junkal)
Airway infection by nontypeable Haemophilus influenzae (NTHi) associates to chronic obstructive pulmonary disease (COPD) exacerbation and asthma neutrophilic airway inflammation. Lipids are key inflammatory mediators in these disease conditions and consequently, NTHi may encounter free fatty acids during airway persistence. However, molecular information on the interplay NTHi-free fatty acids is limited, and we lack evidence on the importance of such interaction to infection. Maintenance of the outer membrane lipid asymmetry may play an essential role in NTHi barrier function and interaction with hydrophobic molecules. VacJ/MlaA-MlaBCDEF prevents phospholipid accumulation at the bacterial surface, being the only system involved in maintaining membrane asymmetry identified in NTHi. We assessed the relationship among the NTHi VacJ/MlaA outer membrane lipoprotein, bacterial and exogenous fatty acids, and respiratory infection. The vacJ/mlaA gene inactivation increased NTHi fatty acid and phospholipid global content and fatty acyl specific species, which in turn increased bacterial susceptibility to hydrophobic antimicrobials, decreased NTHi epithelial infection, and increased clearance during pulmonary infection in mice with both normal lung function and emphysema, maybe related to their shared lung fatty acid profiles. Altogether, we provide evidence for VacJ/MlaA as a key bacterial factor modulating NTHi survival at the human airway upon exposure to hydrophobic molecules.




Relationship between azithromycin susceptibility and administration efficacy for nontypeable Haemophilus influenzae respiratory infection

Zaguán. Repositorio Digital de la Universidad de Zaragoza
  • Euba, B.
  • Moleres, J.
  • Viadas, C.
  • Barberán, M.
  • Caballero, L.
  • Grilló, M.J
  • Bengoechea, J.A.
  • De-Torres, J.
  • Liñares, J.
  • Leiva, J.
  • Garmendia, J.
Nontypeable Haemophilus influenzae (NTHI) is an opportunistic pathogen that is an important cause of acute exacerbations of chronic obstructive pulmonary disease (AECOPD). COPD is an inflammatory disease of the airways, and exacerbations are acute inflammatory events superimposed on this background of chronic inflammation. Azithromycin (AZM) is a macrolide antibiotic with antibacterial and anti-inflammatory properties and a clinically proven potential for AECOPD prevention and management. Relationships between AZM efficacy and resistance by NTHI and between bactericidal and immunomodulatory effects on NTHI respiratory infection have not been addressed. In this study, we employed two pathogenic NTHI strains with different AZM sus- ceptibilities (NTHI 375 [AZM susceptible] and NTHI 353 [AZM resistant]) to evaluate the prophylactic and therapeutic effects of AZM on the NTHI-host interplay. At the cellular level, AZM was bactericidal toward intracellular NTHI inside alveolar and bronchial epithelia and alveolar macrophages, and it enhanced NTHI phagocytosis by the latter cell type. These effects correlated with the strain MIC of AZM and the antibiotic dose. Additionally, the effect of AZM on NTHI infection was assessed in a mouse model of pulmonary infection. AZM showed both preventive and therapeutic efficacies by lowering NTHI 375 bacterial counts in lungs and bronchoalveolar lavage fluid (BALF) and by reducing histopathological inflammatory lesions in the upper and lower airways of mice. Conversely, AZM did not reduce bacterial loads in animals infected with NTHI 353, in which case a milder anti- inflammatory effect was also observed. Together, the results of this work link the bactericidal and anti-inflammatory effects of AZM and frame the efficacy of this antibiotic against NTHI respiratory infection.




Inactivation of the thymidylate synthase thyA in non-typeable Haemophilus influenzae modulates antibiotic resistance and has a strong impact on its interplay with the host airways

Zaguán. Repositorio Digital de la Universidad de Zaragoza
  • Rodríguez-Arce, I.
  • Martí, S.
  • Euba, B.
  • Fernández-Calvet, A.
  • Moleres, J.
  • López-López, N.
  • Barberán, M.
  • Ramos-Vivas, J.
  • Tubau, F.
  • Losa, C.
  • Ardanuy, C.
  • Leiva, J.
  • Yuste, J.E.
  • Garmendia, J.
Antibacterial treatment with cotrimoxazol (TxS), a combination of trimethoprim and sulfamethoxazole, generates resistance by, among others, acquisition of thymidine auxotrophy associated with mutations in the thymidylate synthase gene thyA, which can modify the biology of infection. The opportunistic pathogen non-typeable Haemophilus influenzae (NTHi) is frequently encountered in the lower airways of chronic obstructive pulmonary disease (COPD) patients, and associated with acute exacerbation of COPD symptoms. Increasing resistance of NTHi to TxS limits its suitability as initial antibacterial against COPD exacerbation, although its relationship with thymidine auxotrophy is unknown. In this study, the analysis of 2, 542 NTHi isolates recovered at Bellvitge University Hospital (Spain) in the period 2010–2014 revealed 119 strains forming slow-growing colonies on the thymidine low concentration medium Mueller Hinton Fastidious, including one strain isolated from a COPD patient undergoing TxS therapy that was a reversible thymidine auxotroph. To assess the impact of thymidine auxotrophy in the NTHi-host interplay during respiratory infection, thyA mutants were generated in both the clinical isolate NTHi375 and the reference strain RdKW20. Inactivation of the thyA gene increased TxS resistance, but also promoted morphological changes consistent with elongation and impaired bacterial division, which altered H. influenzae self-aggregation, phosphorylcholine level, C3b deposition, and airway epithelial infection patterns. Availability of external thymidine contributed to overcome such auxotrophy and TxS effect, potentially facilitated by the nucleoside transporter nupC. Although, thyA inactivation resulted in bacterial attenuation in a lung infection mouse model, it also rendered a lower clearance upon a TxS challenge in vivo. Thus, our results show that thymidine auxotrophy modulates both the NTHi host airway interplay and antibiotic resistance, which should be considered at the clinical setting for the consequences of TxS administration.




Resveratrol therapeutics combines both antimicrobial and immunomodulatory properties against respiratory infection by nontypeable Haemophilus influenzae

Zaguán. Repositorio Digital de la Universidad de Zaragoza
  • Euba, B.
  • López-López, N.
  • Rodríguez-Arce, I.
  • Fernández-Calvet, A.
  • Barberán, M.
  • Caturla, N.
  • Martí, S.
  • Díez-Martínez, R.
  • Garmendia, J.
The respiratory pathogen nontypeable Haemophilus influenzae (NTHi) is an important cause of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) that requires efficient treatments. A previous screening for host genes differentially expressed upon NTHi infection identified sirtuin-1, which encodes a NAD-dependent deacetylase protective against emphysema and is activated by resveratrol. This polyphenol concomitantly reduces NTHi viability, therefore highlighting its therapeutic potential against NTHi infection at the COPD airway. In this study, resveratrol antimicrobial effect on NTHi was shown to be bacteriostatic and did not induce resistance development in vitro. Analysis of modulatory properties on the NTHi-host airway epithelial interplay showed that resveratrol modulates bacterial invasion but not subcellular location, reduces inflammation without targeting phosphodiesterase 4B gene expression, and dampens ß defensin-2 gene expression in infected cells. Moreover, resveratrol therapeutics against NTHi was evaluated in vivo on mouse respiratory and zebrafish septicemia infection model systems, showing to decrease NTHi viability in a dose-dependent manner and reduce airway inflammation upon infection, and to have a significant bacterial clearing effect without signs of host toxicity, respectively. This study presents resveratrol as a therapeutic of particular translational significance due to the attractiveness of targeting both infection and overactive inflammation at the COPD airway.