An outbreak of Klebsiella oxytoca septicemias associated with the use of invasive blood pressure monitoring equipment.

Seven cases of septicemia with piperacillin-resistant Klebsiella oxytoca (PRKO) occurred at 2-monthly intervals in a thoracic surgery intensive care unit. All PRKO isolates were serotyped, and phenotyped with a biochemical typing system. Only one patient in the unit was found to be colonized in stool or respiratory tract with PRKO, and this strain was different from the septicemia strains in phenotype though not in serotype. Environmental cultures, from humidifiers, oxygenators, pressure transducers, etc. were negative. PRKO of the epidemic phenotype was recovered from several non-patient transducer domes. The outbreak ended when transducer heads were disinfected and the use of non-patient domes was abolished.