Bacteroides stercorirosoris sp. nov. and Bacteroides faecichinchillae sp. nov., isolated from chinchilla (Chinchilla lanigera) faeces

Abstract

Strains of Gram-negative anaerobic rods were isolated from chinchilla (Chinchilla lanigera) faeces, and three strains, ST161T, ST33 and ST37T, were investigated taxonomically. Based on phylogenetic analyses and specific phenotypic characteristics, the three strains were allocated to the genus Bacteroides . Phylogenetic analyses of their 16S rRNA gene sequences revealed that strain ST161T formed a distinct line of descent, with highest sequence similarity to strain ST33 (98.7 %) and Bacteroides oleiciplenus JCM 16102T (97.7 %). High levels of DNA–DNA relatedness (79–89 %) were found between strains ST161T and ST33, but low levels were found between strain ST161T and B. oleiciplenus JCM 16102T (33–37 %) and between strain ST33 and B. oleiciplenus JCM 16102T (33–37 %). These data clearly indicated that strains ST161T and ST33 represent a single novel species. 16S rRNA gene sequence analyses showed that strain ST37T also formed a distinct line of descent, with highest sequence similarity to Bacteroides acidifaciens JCM 10556T (96.5 %) and Bacteroides caccae JCM 9498T (95.6 %). Analysis of hsp60 gene sequences also supported these relationships. Based on phenotypic and phylogenetic characteristics, two novel species, Bacteroides stercorirosoris sp. nov. and Bacteroides faecichinchillae sp. nov., are thus proposed. The type strains of B. stercorirosoris and B. faecichinchillae are ST161T ( = JCM 17103T = CCUG 60872T) and ST37T ( = JCM 17102T = CCUG 60873T), respectively. The DNA G+C contents of strains ST161T and ST37T were 45.7 and 41.0 mol%, respectively.