Typing of Pseudomonas aeruginosa isolated from patients with VAP in an intensive care unit

Aim of this study was to characterize isolates of Pseudomonas aeruginosa responsible for ventilator-associated pneumonia (VAP) in patients admitted to an ICU in order to evaluate a possible strain clonality. The study was performed from October 2004 to June 2005 in one Southern Italy ICU and 29 patients suspected of having VAP were enrolled. The etiology of VAP was established by quantitative cultures of endotracheal aspirations. Molecular characterization was carried out by PFGE. P. aeruginosa was responsible for 51% of all cases of VAP (15/29) and 12/15 strains were multi-drug resistant. High mortality (44.8%) was connected to this pathogen and evidence of strain clonality was found. The early identification of strain clonality and the application of infection control procedures are necessary to avoid the spread of pathogens such as P. aeruginosa involved in nosocomial infections.