A comparative assay of epidemiological markers for Acinetobacter strains isolated in a hospital.

A comparative assay for epidemiological evaluation of three different Acinetobacter typing procedures, i.e. biotyping, phage-typing, and the analysis of the bacterial envelope protein profiles, was carried out using sixty-four multiresistant Acinetobacter strains isolated from clinical specimens. The antibiotic susceptibility of the strains was also considered. After geno-species identification, biotyping allowed the recognition of a relatively large and long-lasting presence, at an Intensive Therapy Unit, of two A. baumannii biotypes. Phage-typing and the analysis of the susceptibility to antibiotics allowed for the differentiation of strains belonging to different geno-species and biotypes, and in some cases also to the same biotypes. On the contrary, the analysis by polyacrylamide gel electrophoresis of the cell-envelope proteins failed to show any diversity not only within, but also between some of the biotypes of A. baumannii, the most prevalent species of the genus in the hospital environment.