ABSTRACT
BACKGROUND: The glucose -acidifying genomic species 1, 2, 3 and 13 of the genus Acinetobacter are highly related genetically and may be difficult to differentiate by phenotypic identification schemes using biochemical tests. The aim of this study was to explore the brief restriction enzyme profiles of amplified ribosomal DNA restriction analysis (ARDRA) to identify medically important species of Acinetobacter. Using ARDRA analysis, we evaluated the ID 32 GN system (bioMerieux, Lyon, France) for the identification of A. baumannii (genospecies 2). METHODS: A collection of 78 A. baumannii stains initially identified by the ID 32 GN system was used to determine its accuracy by ARDRA analysis. ARDRA was performed with 10 different restriction enzymes, AluI (AGCT), CfoI (GCGC), HaeIII (GGCC), HinfI (GANTC), MboI (GATC), MspI (CCGG), NciI (CCGG), RsaI (GTAC), ScrFI (CCNGG) and TaqI (TCGA). RESULTS: The combination of restriction patterns obtained with respective enzymes AluI, CfoI and MboI allowed for the discriminatory value for the identification of medically important genospecies such as genospecies 2 (A. baumannii), 3 and 13. By comparing ARDRA results of the 78 strains previously identified by ID 32 GN system, we found the correlation rate between the two systems to be 88.5% (69/78). Nine strains were identified as Acinetobacter genospecies 13 by ARDRA. CONCLUSIONS: This result suggests that the ID 32 GN system may have difficulty in discriminating A. baumannii from genospecies 13. This revised ARDRA method gives a relatively rapid and definitive result for the identification of medically important genospecies of Acinetobacter.