title: Host and Pathogen Biomarkers for Severe Pseudomonas aeruginosa Infections.
abstract: Pseudomonas aeruginosa is among the leading causes of severe nosocomial infections, particularly affecting critically ill and immunocompromised patients. Here we review the current knowledge on the factors underlying the outcome of P. aeruginosa nosocomial infections, including aspects related to the pathogen, the host, and treatment. Intestinal colonization and previous use of antibiotics are key risk factors for P. aeruginosa infections, whereas underlying disease, source of infection, and severity of acute presentation are key host factors modulating outcome; delayed adequate antimicrobial therapy is also independently associated with increased mortality. Among pathogen-related factors influencing the outcome of P. aeruginosa infections, antibiotic resistance, and particularly multidrug-resistant profiles, is certainly of paramount relevance, given its obvious effect on the chances of appropriate empirical therapy. However, the direct impact of antibiotic resistance in the severity and outcomes of P. aeruginosa infections is not yet well established. The interplay between antibiotic resistance, virulence, and the concerning international high-risk clones (such as ST111, ST175, and ST235) still needs to be further analyzed. On the other hand, differential presence or expression of virulence factors has been shown to significantly impact disease severity and mortality. The likely more deeply studied P. aeruginosa virulence determinant is the type III secretion system (T3SS); the production of T3SS cytotoxins, and particularly ExoU, has been well established to determine a worse outcome both in respiratory and bloodstream infections. Other relevant pathogen-related biomarkers of severe infections include the involvement of specific clones or O-antigen serotypes, the presence of certain horizontally acquired genomic islands, or the expression of other virulence traits, such as the elastase. Finally, recent data suggest that host genetic factors may also modulate the severity of P. aeruginosa infections.
authors.affiliation: Servicio de Microbiología and Unidad de Investigación, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria de Palma, Palma de Mallorca, and.
authors.forename: Carlos
authors.initials: C
authors.lastname: Juan
authors.affiliation: Servicio de Medicina Interna, Hospital Virgen de los Lirios, Alcoy, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Peña
authors.affiliation: Servicio de Microbiología and Unidad de Investigación, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria de Palma, Palma de Mallorca, and.
authors.forename: Antonio
authors.initials: A
authors.lastname: Oliver
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015415:Biomarkers / Q000097:blood; D003001:Cloning, Molecular; D003428:Cross Infection / Q000097:blood* / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D005819:Genetic Markers; D006801:Humans; D019081:O Antigens / Q000097:blood; D011552:Pseudomonas Infections / Q000097:blood*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity*; D012307:Risk Factors; D000069296:Type III Secretion Systems / Q000097:blood; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D015415:Biomarkers; D005819:Genetic Markers; D019081:O Antigens; D000069296:Type III Secretion Systems; D037521:Virulence Factors
keywords: Pseudomonas aeruginosa; antibiotic resistance; biomarkers; high-risk clones; nosocomial infections; virulence