hsp60 and 16S rRNA gene sequence relationships among species of the genus Bacteroides with the finding that Bacteroides suis and Bacteroides tectus are heterotypic synonyms of Bacteroides pyogenes.

hsp60 gene sequences were determined for members of the genus Bacteroides and sequence similarities were compared with those obtained for the 16S rRNA gene. Among the 29 Bacteroides type strains, the mean sequence similarity of the hsp60 gene (84.5 %) was significantly less than that of the 16S rRNA gene (90.7 %), indicating a high discriminatory power of the hsp60 gene. Species of the genus Bacteroides were differentiated well by hsp60 gene sequence analysis, except for Bacteroides pyogenes JCM 6294(T), Bacteroides suis JCM 6292(T) and Bacteroides tectus JCM 10003(T). The hsp60 gene sequence analysis and the levels of DNA-DNA relatedness observed demonstrated that these three type strains are a single species. Consequently, B. suis and B. tectus are heterotypic synonyms of B. pyogenes. This study suggests that the hsp60 gene is an alternative phylogenetic marker for the classification of species of the genus Bacteroides.