Evaluation of amplified ribosomal DNA restriction analysis for identification of Acinetobacter genomic species

Further to a previous study, the usefulness of amplified ribosomal DNA restriction analysis (ARDRA) for identification of Acinetobacter genomic species (DNA groups) was tested. A set of 202 Acinetobacter strains of 18 described genomic species and 17 unclassified strains were used. Restriction patterns obtained with a standard panel of restriction enzymes CfoI, AluI, MboI, RsaI and MspI allowed for separation of 11 DNA groups. With the additional use of restriction enzymes BfaI and BsmAI, five other (genomic) species could be differentiated, leaving only A. haemolyticus and DNA group 13BJ/14TU unseparated. With the standard panel of enzymes, ten new ARDRA profiles were noted in 14 unclassified strains. Two other unclassified strains had a profile in common with DNA group 15BJ, but were differentiated from this DNA group by restriction with bfaI. One remaining unclassified strain could not be differentiated from DNA group 17 by the standard panel of enzymes or by the enzymes BfaI and BsmAI. Results demonstrate the utility of ARDRA for identification of most genomic species of Acinetobacter. Furthermore, new ARDRA profiles that were shared by several unclassified strains may indicate so far undescribed genomic species in the genus.