Streptococcus Himalayensis Sp Nov., Isolated From The Respiratory Tract Of Marmota Himalayana

Five strains of Gram-positive-staining, catalase-negative, coccus-shaped, chain-forming organisms isolated separately from the respiratory tracts of five Marmota himalayana animals in the Qinghai-Tibet Plateau of China were subjected to phenotypic and molecular taxonomic analyses. Comparative analysis of the 16S rRNA gene indicated that these singular organisms represent a new member of the genus Streptococcus, being phylogenetically closest to Streptococcus marmotae DSM 101995(T) (98.4% similarity). The groEL, sodA and rpoB sequence analysis showed interspecies similarity values between HTS2(T) and Streptococcus. marmotae DSM 101995(T), its closest phylogenetic relative based on 16S rRNA gene sequences, of 98.2, 78.8 and 93.7 %, respectively. A whole-genome phylogenetic tree built from 82 core genes of genomes from 16 species of the genus Streptococcus validated that HTS2(T) forms a distinct subline and exhibits specific phylogenetic affinity with S. marmotae. In silico DNA-DNA hybridization of HTS2(T) showed an estimated DNA reassociation value of 40.5% with Streptococcus. marmotae DSM 101995(T). On the basis of their phenotypic characteristics and phylogenetic findings, it is proposed that the five isolates be classified as representatives of a novel species of the genus Streptococcus, Streptococcus himalayensis sp. nov. The type strain is HTS2(T) (=DSM 101997(T) = CGMCC 1.15533(T)). The genome of Streptococcus himalayensis sp. nov. strain HTS2(T) contains 2195 genes with a size of 2 275 471 bp and a mean DNA G+C content of 41.3 mol%.