Type III protein secretion is associated with poor clinical outcomes in patients with ventilator-associated pneumonia caused by

te Objective: Pseudomonas aeruginosa is a frequent cause of ventilator-associated pneumonia. Recent evidence suggests that production of type III secretion proteins is correlated with increased pathogenicity in both cellular and animal models of infection. The objective of this study was to determine whether this system contributes to disease severity in humans with ventilator -associated pneumonia. Design: Retrospective pilot cohort study. Setting: University hospital. Patients: Thirty-five mechanically ventilated patients with bronchoscopically confirmed ventilator-associated pneumonia caused by P. aeruginosa. Measurements and Main Results: Ventilator-associated pneumonia was categorized as severe (patients died or had a recurrence of their pneumonia despite appropriate antibiotic therapy) or mild (patients uneventfully recovered from their pneumonia). The type III secretion genotypes and phenotypes of isolates cultured from the patients with ventilator-associated p