dnaJ gene sequence-based assay for species identification and phylogenetic grouping in the genus Staphylococcus

Abstract

In the last few years, many attempts have been made to use conserved gene sequences for identification and for phylogenetic studies ofStaphylococcusspecies. In an effort to identify a more reliable approach, adnaJgene sequence-based database was created. In this study, an approximately 883 bp portion of thednaJgene sequence from 45 staphylococcal type strains was compared with 16S rRNA and other conserved gene (hsp60,sodAandrpoB) sequences available in public databases. Nucleotide sequence comparisons revealed that the staphylococcaldnaJgene showed higher discrimination (mean similarity 77.6 %) than the 16S rRNA (mean similarity 97.4 %),rpoB(mean similarity 86 %),hsp60(mean similarity 82 %) andsodA(mean similarity 81.5 %) genes. Analysis of thednaJgene sequence from 20Staphylococcusisolates representing two clinically important species showed <1 % sequence divergence. Phylogenetic data obtained from thednaJgene sequence were in general agreement with those of 16S rRNA gene sequence analysis and DNA–DNA reassociation studies. In conclusion, thednaJgene sequence-based assay is an effective alternative to currently used methods, including 16S rRNA gene sequencing, for identification and taxonomical analysis ofStaphylococcusspecies.