Evaluation of the ability of a commercial system to identifyAcinetobacter genomic species

Abstract

A collection of 130Acinetobacter strains identified by DNA hybridization to 18 different genomic species was used to assess the ability of the API 20NE system (bioMérieux, France) to identifyAcinetobacter genomic species and to determine its accuracy. Fiftyeight (87%) of the 67 strains of genomic species defined in the database (version 5.1) were identified to the appropriate genomic species. TheAcinetobacter baumannii strains and theAcinetobacter haemolyticus strains were all identified correctly. Three of fiveAcinetobacter junii strains, three of eightAcinetobacter johnsonii strains, and 11 of 13Acinetobacter Iwoffii strains were also identified correctly. The 58 correctly identified strains represented 45% of the total 130 strains. Thirty-six of the 72 inappropriately identified strains were designatedAcinetobacter baumannii. Thirty-one of these 36 strains belonged to genomic species 1 (Acinetobacter calcoaceticus), 3, or 13TU. Analysis of the profiles showed that the API system does not discriminate between genomic species 1, 2, 3, and 13TU. Lumping of these groups into theAcinetobacter calcoaceticus-Acinetobacter baumannii complex in the API 20NE database would make the system considerably more accurate. Incorporation of these data into the database may improve identification of the remaining genomic species, including some that are not defined. However, the discriminative power of the tests in the API galleries is insufficient for correct identification of allAcinetobacter genomic species.