Transmission of a multiresistant Pseudomonas aeruginosa strain at a Germanuniversity hospital

Over 15 months, 60 patients at a German University Hospital became infected or colonized by a multiresistant Pseudomonas aeruginosa strain, which was isolated from tracheal secretions, blood, urine, venous catheters, ascites and several wounds. Most patients had undergone invasive treatment (surgery , cancer therapy). The genetic relationship of the isolates was investigated by pulsed field g el electrophoresis. The isolates were resistant to beta -lactam antibiotics , including carbapenems and aztreonam, to aminoglycosides and quinolones. T he only in vitro susceptibility was to polymyxin B. Extensive sampling was carried out to identify contaminated medical devices , surfaces or media (water, food). Samples were taken from doctors and nurs ing staff and various treatment procedures were observed for several weeks. The handling of respirators, resuscitation tubes, urine bottles, and bedpa ns resulted in the contamination of the patients' environment, although mos t devices were cleaned and disinfected with automatic washer/disinfectors. Several wash basins on the intensive care unit were contaminated, but none of the drinking water samples showed any growth of P. aeruginosa. We recommend the strict use of gloves and strict application of alcoholic h and disinfectants immediately after discarding the gloves. The chain of inf ection ceased after strict cohort isolation and the subsequent introduction of the specific hygiene regime. (C) 2001 The Hospital Infection Society.