During a 12-day period, nine patients developed bacteremia with gentamicin-resistant Serratia marcescens in the surgical intensive care unit (SICU). These bacteremias differed from previous Serratia infections in the SICU in that they occurred in patients without earlier colonization of the organism at other sites. All cases occurred in one area of the SICU. The clinical syndrome suggested direct intravenous (IV) inoculation. Environmental cultures revealed gentamicin-resistant Serratia in pooled handwashings, on the surface of a patient IV bag, and in a bag of heparinized saline solution used for opening blocked IV tubes. All environmental and eight of nine patient isolates were serotype 0 indeterminate: Hl. The organisms were capable of growth in the heparinized saline solution (10/U ml). Within 6 days, colony counts exceeded 106 organisms/ml. Organisms did not grow in a concentrated heparin solution (500 U/ml); however, they were able to survive for a minimum of 3 days. Heparinized saline solution may have acted as a vehicle in this outbreak.
ASJC Scopus subject areas
- Health Policy
- Public Health, Environmental and Occupational Health
- Infectious Diseases