Study on genotyping in clinical Acinetobacter calcoaceticus-Acinetobacter baumannii complex

Objective To investigate the effective methods for identification of all the genotypes of Acinetobacter speciese, including Acinetobacter calcoaceticus-Acinetobacter baumannii (ACB) complex.

Methods For all ACB complex strains, bacterial identification was carried out using automatic bacteria identification system.Additionally, for more accurate discrimination between ACB complex species, Molecular Biology methods has been combined? with, all ACB complex strains were further subjected to polymerase chain reaction (PCR) amplification to detect the A.baumannii-specific expression of the class D carbapenemase gene OXA-51, 16S rRNA gene and ACB complex gyrB genes, which specifically expressed in each species.

Results Totally all 20 ACB complex strains were identified as ACB complex by automatic bacteria identification system; which were identified by the method in Molecular Biology by PCR, of them 3 A.calcoaceticus strains and 1 A.nosocomialis strain were detected in ACB complex, together with 16 Acinetobacter baumannii strains.

Conclusions The combination of automatic bacteria identification system and Molecular Biology methods can provide more accurate genospecies identification in ACB complex.gyrB gene might be a more effective marker in the identification of highly phylogenetic related species.