Department of Oral Microbiology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba 271-8587, Japan.
Laboratory Medicine for Dentistry, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba 271-8587, Japan.
Int J Syst Evol Microbiol. 2013 Aug;63(Pt 8):2782-2786. doi: 10.1099/ijs.0.047142-0. Epub 2013 Jan 4.
Four Gram-positive, catalase-negative, coccoid isolates that were obtained from donkey oral cavities formed two distinct clonal groups when characterized by phenotypic and phylogenetic studies. From the results of biochemical tests, the organisms were tentatively identified as a streptococcal species. Comparative 16S rRNA gene sequencing studies confirmed the organisms to be members of the genus Streptococcus. Two of the isolates were related most closely to Streptococcus ursoris with 95.6 % similarity based on the 16S rRNA gene and to Streptococcus ratti with 92.0 % similarity based on the 60 kDa heat-shock protein gene (groEL). The other two isolates, however, were related to Streptococcus criceti with 95.0 and 89.0 % similarities based on the 16S rRNA and groEL genes, respectively. From both phylogenetic and phenotypic evidence, the four isolates formed two distinct clonal groups and are suggested to represent novel species of the genus Streptococcus. The names proposed for these organisms are Streptococcus orisasini sp. nov. (type strain NUM 1801(T) = JCM 17942(T) = DSM 25193(T)) and Streptococcus dentasini sp. nov. (type strain NUM 1808(T) = JCM 17943(T) = DSM 25137(T)).
从驴口腔中分离得到的四株革兰氏阳性、触酶阴性、球形的分离株，通过表型和系统发育研究，可分为两个不同的克隆群。根据生化试验结果，这些生物体被初步鉴定为链球菌属的一个种。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。其中两个分离株与 Streptococcus ursoris 的相似度最高，基于 16S rRNA 基因相似度为 95.6%，基于 60 kDa 热休克蛋白基因（groEL）相似度为 92.0%。然而，另外两个分离株与 Streptococcus criceti 的相似度分别为 95.0%和 89.0%，基于 16S rRNA 和 groEL 基因。从系统发育和表型证据来看，这四个分离株形成了两个不同的克隆群，建议它们代表链球菌属的新种。这些生物体的名称分别为 Orisasini 链球菌（NUM 1801(T) = JCM 17942(T) = DSM 25193(T)，模式株）和 Dentasini 链球菌（NUM 1808(T) = JCM 17943(T) = DSM 25137(T)，模式株）。
