NOSOCOMIAL COLONIZATION AND INFECTION BY MULTIRESISTANT PSEUDOMONAS-AERUGINOSA STRAINS IN AN INTENSIVE-CARE UNIT

Pseudomonas aeruginosa is often isolated from intensive care patients. During 1993, 1093 P. aeruginosa strains were isolated in our laborato ry and more than 50% (549) were cultured from specimens from the surgi cal intensive care unit. The antibiotic sensitivity varied in differen t wards and the isolates from hospitalised patients were more resistan t than those from outpatients. Between July and November 1993, a P. ae ruginosa strain resistant to acylaminopenicillins, cephalosporins, qui nolones and aminoglycosides and only moderately sensitive to amikacin, spread in the surgical intensive care unit. The multiresistant strain was isolated from 96 specimens including, blood cultures, catheter ti ps, wound swabs, drains, tracheal secretions, bronchial secretions, th roat swabs, nasal swabs, urine and once from the environment. The resu lt of subtyping (Restriction-Fragment-length-Polymorphism and pyocin-t yping) revealed, that in five patients and one environmental isolate, the RFLP- and pyocin-type was identical. Phenotypic and genotypic meth ods were equivalent for the identification. All five patients had a no socomial infection. The riskfactors in infected patients and noninfect ed controls were compared. Infected patients had prolonged intubation and longer hospital stay (11 days).