Distribution of Acinetobacter species on skin of healthy humans

The distribution of the 19 currently known genospecies of Acinetobacter on human skin, i.e. forehead, forearm and toe webs, was determined. Three sele ctive media were compared for their specificity for all genospecies of Acin etobacter. A minimal-salts agar supplemented with 1% acetate proved to be m ore efficient than the Leeds medium for the isolation of most genospecies i n mixed culture with other bacterial species. Acinetobacter isolates were p rovisionally identified using biochemical tests and the DNA transformation assay of Juni. Genospecies identification was performed using amplified rib osomal DNA restriction analysis, and duplicate isolates of the same genospe cies from individuals were ruled out by random amplified polymorphic DNA an alysis. Over 40% of 192 healthy volunteers carried Acinetobacter spp. at on e or more body sites, and the frequencies of colonisation were as follows: forearm (51%), forehead (47%) and toe web (34%). Genospecies 8/9 (Acinetoba cter lwoffii) was the most common (61%), followed by genospecies 15BJ and 1 2 (Acinetobacter radioresistens) at 12.5% and 8%, respectively. The Acineto bacter baumannii-Acinetobacter calcoaceticus group (genospecies 1, 2, 3 and 13TU) that predominates in hospital-acquired infections was found in only one individual.