Tjernberg, I. & Ursing. J. Clinical strains of ,lcinewhartrr classified by DNA-DNA hybridization. APMIS A collection of .-lcincrohn~tcr strains consisting of I68 consecutive clinical strains and 30 type and reference strains was studied by DNA-DNA hybridization and a few phenotypic tests. The field strains could be allotted to 13 DNA groups. By means of reference strains ten of these could be identified with groups described by Boiriw & Grirnonr (1986). while three groups were new: they were given the numbers 13-1 5. The type strain of .4. ruclior~~.~i.s,m.~recently described by Ni. rhimuru et al. ( 1988) was shown to be a member of DNA group 12. which comprised 3 1 clinical isolates. Of the 19 strains of A . ,jrinii. eight showed hemolytic activity on sheep and human blood agar and an additional four strains on human blood agar only.Strains of this species have previously been regarded as non-hemolytic. Reciprocal DNA pairing data for the reference strains of the DNA groups were treated by UPGMA clustering. The reference strains for .4. c~~~l~~o u r c~~i c~i r .~..4. haiiriiannii and for DNA groups 3 and 13 formed a cluster with about 70% relatedness within the cluster. Other DNA groups joined at levels below 6OYn.

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hydrolysis, and assimilation of 14 carbon sources. Of the strains tested, 181 represented 12 DNA groups in the matrix; at a probability level of .0.95, 78% of them were correctly identified, 2.2% were misidentified, and 19.8% were not identified. Seventeen strains represented two DNA groups not included in the matrix; nine of them were incorrectly assigned to a DNA group by these phenotypic tests. Because of problems of separating strains belonging to DNA groups 1, 2, 3, and 13 by using the phenotypic tests proposed by Bouvet and Grimont (Ann. Inst. Pasteur/Microbiol.), we suggest that these groups should be referred to as the Acinetobacter calcoaceticus-A. baumannii complex.

At least 19 genomic species are recognized as constituting the genus Acinetobacter. However, little is known about the natural reservoirs of the various members of the genus. An epidemiological study was therefore performed to investigate the colonization with Acinetobacter spp. of the skin and mucous membranes of 40 patients hospitalized in a cardiology ward and 40 healthy controls. Single samples were obtained once from each of nine different body sites, i.e., forehead, ear, nose, throat, axilla, hand, groin, perineum, and toe web. Identification of Acinetobacter isolates was achieved by using phenotypic properties and was compared to identification by amplified ribosomal DNA restriction analysis. Selected isolates were further investigated with sodium dodecyl sulfate-polyacrylamide gel electrophoresis, ribotyping, and DNA-DNA hybridization. Plasmid profile analysis was used for epidemiological typing. Thirty patients (75%) and 17 controls (42.5%) were found to be colonized with Acinetobacter spp., and the colonization rates of patients increased during their hospital stay. The most frequently isolated species were Acinetobacter lwoffii (47%), A. johnsonii (21%), A. radioresistens (12%), and DNA group 3 (11%). In contrast, A. baumannii and DNA group 13TU, the most important nosocomial Acinetobacter spp., were found only rarely on human skin (0.5 and 1%, respectively) and their natural habitat remains to be defined. A good correlation between phenotypic and genotypic methods for identification of Acinetobacter spp. was observed, and only two isolates could not be assigned to any of the known DNA groups.