Department of Oral Microbiology, Nihon University School of Dentistry at Matsudo, Chiba 271-8587, Japan.
Int J Syst Evol Microbiol. 2014 Sep;64(Pt 9):3288-3292. doi: 10.1099/ijs.0.063263-0. Epub 2014 Jul 3.
Four Gram-stain-positive, catalase-negative, coccoid-shaped organisms were isolated from elephant oral cavities. The isolates were tentatively identified as streptococcal species based on the results of biochemical tests. Comparative 16S rRNA gene sequencing studies confirmed the organisms to be members of the genus Streptococcus. Two isolates (NUM 6304(T) and NUM 6312) were related most closely to Streptococcus salivarius with 96.8 % and 93.1 % similarity based on the 16S rRNA gene and the RNA polymerase β subunit encoding gene (rpoB), respectively, and to Streptococcus vestibularis with 83.7 % similarity based on the 60 kDa heat-shock protein gene (groEL). The other two isolates (NUM 6306(T) and NUM 6318) were related most closely to S. vestibularis with 97.0 % and 82.9 % similarity based on the 16S rRNA and groEL genes, respectively, and to S. salivarius with 93.5 % similarity based on the rpoB gene. Based on phylogenetic and phenotypic evidence, these isolates are suggested to represent novel species of the genus Streptococcus, for which the names Streptococcus loxodontisalivarius sp. nov. (type strain NUM 6304(T) = JCM 19287(T) = DSM 27382(T)) and Streptococcus saliviloxodontae sp. nov. (type strain NUM 6306(T) = JCM 19288(T) = DSM 27513(T)) are proposed.
从大象口腔中分离到四株革兰氏阳性、触酶阴性、球形的细菌。根据生化试验结果，这些分离株被初步鉴定为链球菌属的种。比较 16S rRNA 基因测序研究证实这些菌为链球菌属的成员。两个分离株（NUM 6304(T)和 NUM 6312）与唾液链球菌（Streptococcus salivarius）的 16S rRNA 基因和 RNA 聚合酶β亚基编码基因（rpoB）的相似度最高，分别为 96.8%和 93.1%，与前庭链球菌（Streptococcus vestibularis）的相似度为 83.7%，基于 60 kDa 热休克蛋白基因（groEL）。另外两个分离株（NUM 6306(T)和 NUM 6318）与前庭链球菌的相似度最高，基于 16S rRNA 和 groEL 基因的相似度分别为 97.0%和 82.9%，基于 rpoB 基因与唾液链球菌的相似度为 93.5%。基于系统发育和表型证据，这些分离株被建议代表链球菌属的新种，分别命名为唾液链球菌亚种（loxodontalisalivarius）（模式株 NUM 6304(T) = JCM 19287(T) = DSM 27382(T)）和洛氏链球菌亚种（saliviloxodontae）（模式株 NUM 6306(T) = JCM 19288(T) = DSM 27513(T)）。
