Patterns of colonization by Pseudomonas aeruginosa in intubated patients: a 3-year prospective study of 1,607 isolates using pulsed-field gel electrophoresis with implications for prevention of ventilator-associated pneumonia.
Valles, Jordi 1; Mariscal, Dolors 2; Cortes, Pilar 3; Coll, Pere 3,4; Villagra, Ana 1; Diaz, Emili 1; Artigas, Antonio 1; Rello, Jordi 5
[Article]
Intensive Care Medicine.
30(9):1768-1775, September 2004.
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Objective: To identify routes and patterns of colonization with Pseudomonas aeruginosa in intubated patients to design strategies of prevention for respiratory infection.
Design and setting: Prospective and observational study in the 16-bed intensive care unit of a teaching hospital.
Patients and participants: Ninety-eight intubated patients were investigated over a 3-year period. Those ventilated less than 72 h were excluded.
Measurements and results: Samples from the tap water from each patient's room, stomach, oropharynx, subglottic secretions, trachea, and rectum were collected when the patient was intubated, and then three times per week. Pulsed-field gel electrophoresis was performed to type the strains. We identified 1,607 isolates pertaining to 35 different pulsotypes. Overall 54.2% of patients presented colonization, and tracheal colonization was present in 30.5%. Ten patients had colonization at intubation, and four of these developed ventilator-associated pneumonia (VAP) after a mean of 4 /-2 days. ICU-acquired colonization occurred in 31 patients, and 4 of these developed VAP after a median of 10 /-5 days. P. aeruginosa was isolated from the room's tap water in 62.4% of samples. More than 90% of tap water samples had pulsotypes 1 and 2, which were frequently isolated in the stomach (59%) but were only rarely associated with VAP.
Conclusions: Although colonization/infection with P. aeruginosa in intubated patients tends to be endogenous, exogenous sources should not be ruled out. A combination of early identification (and eradication) of airways colonization by P. aeruginosa plus infection control measures targeted to reduce cross-contamination should be the basis to prevent pulmonary infection.
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