A large outbreak of multiresistant Pseudomonas aeruginosa strains in north-eastern Germany

Multiply-resistant Pseudomonas aeruginosa were first detected in north-east ern Germany at the end of 1996; since then they have been isolated predomin antly from patients in intensive care units. Colonization/infection, especi ally of the respiratory tract, has been demonstrated in 80 patients, with s trains resistant to beta-lactams, carbapenems, aminoglycosides and quinolon es. Amikacin showed in-vitro synergy with cefepime, ceftazidime or piperaci llin/tazobactam. Horizontal transfer of strains was followed by PFGE and id entical strains were detected in the environment, but the source of infecti on was not established. Rigorous infection control and restricted clinical use of carbapenems limited further dissemination of this outbreak.