Usefulness of the hsp60 gene for the identification and classification of Gram-negative anaerobic rods

Abstract

Thehsp60gene sequences were determined for 121 strains of Gram-negative anaerobic rods, including the generaBacteroides,Barnesiella,Butyricimonas,Odoribacter,Parabacteroides,Paraprevotella,Porphyromonas,PrevotellaandTannerella. The mean pairwisehsp60gene sequence similarity (73.8–97.1 %) between species in each genus, except for the genusTannerellathat comprises one species, was significantly less than that of the 16S rRNA gene sequence (88.3–96.3 %). Only pairwisehsp60gene sequence similarity (97.1 %) of the genusParaprevotellawas higher than that of the 16S rRNA gene sequence (93.8 %). Each genus formed a distinct clade in the phylogenetic analysis of thehsp60gene sequence as well as the 16S rRNA gene sequence. The phylogenetic analysis indicated a higher evolutionary rate for thehsp60gene sequence than the 16S rRNA gene sequence, especially in the generaPorphyromonasandPrevotella. This study suggests that thehsp60gene is a useful alternative phylogenetic marker for the identification and classification of a broad range of Gram-negative anaerobic rods.