ENDEMIC ACINETOBACTER IN INTENSIVE-CARE UNITS - EPIDEMIOLOGY AND CLINICAL IMPACT

Aims-To assess whether Acinetobacter isolates obtained over 20 months in a tertiary care hospital were epidemiologically related; to establi sh the clinical importance of the organisms; and to identify the isola tes according to the recent taxonomy. Methods-Fifty eight Acinetobacte r isolates from 49 patients collected during 1984 and 1985 were invest igated. Most isolates were from respiratory tract specimens from inten sive care patients. The organisms were typed by cell envelope protein electrophoresis and by a quantitative carbon source growth assay; pati ents' charts were reviewed to differentiate between colonisation and i nfection; representative isolates were identified to species level by DNA-DNA hybridisation. Results-Twelve protein profiles were distinguis hed in the isolates. Forty two isolates were of the same protein profi le (profile I); other profiles were observed in a few or single isolat es. Cluster analysis of carbon source growth divided profile I isolate s into two groups-one of isolates from 1984 and one from 1985. They we re identified as A baumannii and associated with infections in eight p atients. Four other infections were caused by acinetobacters with othe r protein profiles (three of A baumannii; one of the unnamed DNA group 3). Conclusions-Apart from sporadic strains, two strains of the same protein profile, but distinguishable by carbon source growth, were suc cessively endemic. Cluster analysis was a valuable tool in the interpr etation of typing and epidemiological data. The 12 (28%) infections of Acinetobacter in 43 patients in intensive care suggest that the prese nce of these organisms in wards of severely ill patients should be a c ause of concern.