Influence of Virulence Genotype and Resistance Profile in the Mortality of Pseudomonas aeruginosa Bloodstream Infections

Background. The type III secretion system (TTSS) is a major virulence determinant of Pseudomonas aeruginosa. The objective of this study was to determine whether the TTSS genotype is a useful prognostic marker of P. aeruginosa bacteremia mortality. We also studied the potential association between T...

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Detalles Bibliográficos
Autores: Pena, C, Cabot, G, Gomez-Zorrilla, S, Zamorano, L, Ocampo-Sosa, A, Murillas, J, Almirante, B, Pomar, V, Aguilar, M, Granados, A, Calbo, E, Rodriguez-Bano, J, Rodriguez-Lopez, F, Tubau, F, Martinez-Martinez, L, Oliver, A
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2015
País:España
Institución:Institut d’Investigació Biomèdica Sant Pau (IIB Sant Pau)
Repositorio:r-IIB SANT PAU. Repositorio Institucional de Producción Científica del Instituto de Investigación Biomédica Sant Pau
OAI Identifier:oai:iibsantpau.fundanetsuite.com:p14614
Acceso en línea:https://iibsantpau.fundanetsuite.com/Publicaciones/ProdCientif/PublicacionFrw.aspx?id=14614
Access Level:acceso abierto
Palabra clave:type III secretion system
multidrug resistance
virulence
bloodstream infections
Pseudomonas aeruginosa
Descripción
Sumario:Background. The type III secretion system (TTSS) is a major virulence determinant of Pseudomonas aeruginosa. The objective of this study was to determine whether the TTSS genotype is a useful prognostic marker of P. aeruginosa bacteremia mortality. We also studied the potential association between TTSS genotypes and multidrugresistant (MDR) profiles, and how this interaction impacts the outcome of bloodstream infections. Methods. We performed a post hoc analysis of a published prospective multicenter cohort of P. aeruginosa bloodstream infections. The impact in mortality of TTSS genotypes (exoS, exoT, exoU, and exoY genes) and resistance profiles was investigated. Cox regression analysis was used to control for confounding variables. Results. Among 590 patients, the 30-day mortality rate was 30% (175 patients), and 53% of them died in the first 5 days (early mortality). The unadjusted probabilities of survival until 5 days was 31.4% (95% confidence interval [CI], 17.4%-49.4%) for the patients with exoU-positive isolates and 53.2% (95% CI, 44.6%-61.5%) for exoU-negative isolates (log rank P = .005). After adjustment for confounders, exoU genotype (adjusted hazard ratio [aHR], 1.90 [95% CI, 1.15-3.14]; P = .01) showed association with early mortality. In contrast, late (30-day) mortality was not influenced by TTSS genotype but was independently associated with MDR profiles (aHR, 1.40 [95% CI, 1.01-1.94]; P = .04). Moreover, the exoU genotype (21% of all isolates) was significantly less frequent (13%) among MDR strains (particularly among extensively drug-resistant isolates, 5%), but was positively linked to moderately resistant (1-2 antipseudomonals) phenotypes (34%). Conclusions. Our results indicate that the exoU genotype, which is associated with specific susceptibility profiles, is a relevant independent marker of early mortality in P. aeruginosa bacteremia.