title: 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.
abstract: OBJECTIVE
  To identify routes and patterns of colonization with Pseudomonas aeruginosa in intubated patients to design strategies of prevention for respiratory infection.
  
  
  METHODS
  Prospective and observational study in the 16-bed intensive care unit of a teaching hospital.
  
  
  METHODS
  Ninety-eight intubated patients were investigated over a 3-year period. Those ventilated less than 72 h were excluded.
  
  
  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.
authors.affiliation: Critical Care Center, Hospital Sabadell and UDIAT Diagnostic Center, Institut Universitari, Universitat Autónoma Barcelona, Parc Tauli s/n, 08208 Sabadell, Spain. jvalles@cspt.es
authors.forename: Jordi
authors.initials: J
authors.lastname: Vallés
authors.forename: Dolors
authors.initials: D
authors.lastname: Mariscal
authors.forename: Pilar
authors.initials: P
authors.lastname: Cortés
authors.forename: Pere
authors.initials: P
authors.lastname: Coll
authors.forename: Ana
authors.initials: A
authors.lastname: Villagrá
authors.forename: Emili
authors.initials: E
authors.lastname: Díaz
authors.forename: Antonio
authors.initials: A
authors.lastname: Artigas
authors.forename: Jordi
authors.initials: J
authors.lastname: Rello
mesh_terms: D000368:Aged; D003428:Cross Infection / Q000382:microbiology / Q000517:prevention & control; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006761:Hospitals; D006801:Humans; D007362:Intensive Care Units; D007440:Intubation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000175:diagnosis / Q000209:etiology* / Q000382:microbiology; D011446:Prospective Studies; D011552:Pseudomonas Infections / Q000175:diagnosis / Q000209:etiology* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification*; D012121:Respiration, Artificial / Q000009:adverse effects