RESUMO
The taxonomic position of four phenotypically closely related strains isolated from faecal samples of yaks (Bos grunniens) collected from the Qinghai-Tibetan plateau, China, was determined by a polyphasic approach. The strains were non-spore-forming, non-motile Gram-stain-positive, ovoid cocci, occurring predominantly in pairs and short chains or in irregular clusters. The 16S rRNA gene of strain MN05T was related phylogenetically to those of Enterococcushaemoperoxidus, Enterococcusrotai, Enterococcusquebecensis, Enterococcusplantarum, Enterococcuscrotali, Enterococcusmoraviensis, Enterococcussilesiacus, Enterococcuscaccae, Enterococcustermitis, Enterococcusureasiticus and Enterococcusureilyticus, all belonging to the Enterococcusfaecalis species group. The sequence similarities of three selected genes of MN05T to those of the type strains of phylogenetically related species were measured, with values within the range of 99.2-99.5â% (16S rRNA gene), 90.0-97.3â% (rpoA) and 80.0-85.3â% (pheS), respectively. The genome of MN05T (3â842â361 bp) contained 4299 genes with a DNA G+C content of 37.5 mol%. A whole-genome phylogenetic tree based on 808 core genes confirmed that MN05T belongs to a distinct lineage, well separated from all recognized species of the Enterococcusfaecalis species group. DNA-DNA hybridization in silico showed that MN05T displayed less than 70â% DNA-DNA relatedness with the other 13 species of the Enterococcusfaecalis species group. Moreover, their phenotypic features distinguished the four strains from the other species of the Enterococcusfaecalis species group. Based upon these data obtained from the polyphasic characterization performed in the present study, a novel species of the genus Enterococcus, Enterococcus wangshanyuanii sp. nov., is proposed, with the type strain MN05T (=DSM 104047T=CGMCC 1.15942T).