PCR differentiation of seventeen genospecies of Acinetobacter

In the present study, strains of 17 reference Acinetobacter genospecies were investigated by using the polymerase chain reaction (PCR). We used primers to amplify spacer regions between the 16S and 23S genes in the prokaryotic rRNA genetic loci. When the spacer amplification products were resolved by electrophoresis, the resulting patterns could be used to distinguish all of the tested acinetobacters into 15 groups. The genospecies 5 (Acinetobacter junii), 7 (Acinetobacter johnsonii) and 10 produced the same characteristic PCR patterns, suggesting the identity of these three genospecies. A preliminary evaluation of the proposed scheme for PCR diagnostics was carried out. Using the proposed scheme, tested clinical strains were identified correctly to the genospecies level, and the identifications confirmed by conventional biochemical tests. On the basis of our results, PCR amplification of the 16S-23S spacer region shows significant promise as a tool for the simple identification of genospecies belonging to Acinetobacter sp. The nucleotide sequences of our primers are sufficiently highly conserved among these organisms as to permit PCR reactions to be carried out with a single set of reaction conditions and amplification parameters irrespective of species or genus.