Department of Microbiology and Immunology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba 271-8587, Japan.
Int J Syst Evol Microbiol. 2011 Jan;61(Pt 1):40-44. doi: 10.1099/ijs.0.019638-0. Epub 2010 Feb 5.
Three Gram-positive, catalase-negative, coccus-shaped organisms were isolated from the oral cavities of bears. The isolates were tentatively identified as a streptococcal species based on the results of biochemical tests. Comparative 16S rRNA gene sequencing studies confirmed that the organisms were members of the genus Streptococcus, but they did not correspond to any recognized species of the genus. The nearest phylogenetic relative of the new isolates was Streptococcus ratti ATCC 19645(T) (98.6 %), however, DNA-DNA hybridization analysis showed that the isolates displayed less than 15 % DNA-DNA relatedness with the type strain of S. ratti. Colonies of the novel strains grown on mitis salivarius agar showed an extracellular polysaccharide-producing colony morphology. Based on phenotypic and phylogenetic evidence, it is proposed that the novel isolates are classified in the genus Streptococcus as Streptococcus ursoris sp. nov. The type strain of S. ursoris is NUM 1615(T) (=JCM 16316(T)=DSM 22768(T)).
从熊的口腔中分离出三株革兰氏阳性、触酶阴性、球菌状的微生物。根据生化试验的结果，这些分离物被初步鉴定为链球菌属的一种。比较 16S rRNA 基因测序研究证实，这些生物体是链球菌属的成员，但它们与该属的任何公认种都不对应。新分离株的最近亲缘关系是屎肠球菌 ATCC 19645(T)(98.6%)，然而，DNA-DNA 杂交分析表明，分离株与屎肠球菌的模式株的 DNA-DNA 同源性小于 15%。在含唾液链球菌的琼脂上生长的新型菌株的菌落显示出一种产生细胞外多糖的菌落形态。基于表型和系统发育证据，建议将新型分离株归类为链球菌属中的松鼠链球菌。松鼠链球菌的模式株为 NUM 1615(T)(=JCM 16316(T)=DSM 22768(T))。
