Tong Huichun, Gao Xuejun, Dong Xiuzhu
Department of Cariology, Endodontology and Operative Dentistry, School of Stomatology, Peking University, Beijing 100081, P. R. China.
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, P. R. China.
Int J Syst Evol Microbiol. 2003 Jul;53(Pt 4):1101-1104. doi: 10.1099/ijs.0.02493-0.
Five streptococcal strains were isolated from dental plaque and saliva of caries-free humans. The cells were gram-positive, non-spore-forming, non-motile cocci that were arranged in short chains. The strains were catalase-negative, facultatively anaerobic and produced lactic acid exclusively from glucose fermentation. Biochemical analysis that used both conventional methods and the commercial API 20 Strep system showed that the five strains fermented only a few kinds of sugar. The mean DNA G + C content of the five novel strains was 39.5 +/- 0.8 mol%. Phylogenetic analysis based on 16S rDNA sequence homology indicated that the new isolates represented a novel member of the mitis group of the genus Streptococcus, related most closely to the recently described species Streptococcus sinensis. DNA-DNA relatedness between novel strain LMG 21535T and type strains of phylogenetically related species of oral streptococci was 7.1-16.4%. Therefore a novel Streptococcus species, Streptococcus oligofermentans sp. nov., is proposed. The type strain is LMG 21535T=AS 1.3089T.
从无龋人类的牙菌斑和唾液中分离出五株链球菌菌株。这些细胞为革兰氏阳性、不形成芽孢、无运动性的球菌，呈短链排列。这些菌株过氧化氢酶阴性，兼性厌氧，仅通过葡萄糖发酵产生乳酸。使用传统方法和商业API 20 Strep系统进行的生化分析表明，这五株菌株仅发酵少数几种糖类。这五株新菌株的平均DNA G + C含量为39.5 +/- 0.8 mol%。基于16S rDNA序列同源性的系统发育分析表明，这些新分离株代表链球菌属缓症链球菌群的一个新成员，与最近描述的中华链球菌关系最为密切。新菌株LMG 21535T与口腔链球菌系统发育相关物种的模式菌株之间的DNA-DNA相关性为7.1-16.4%。因此，提出了一个新的链球菌物种，少发酵链球菌（Streptococcus oligofermentans sp. nov.）。模式菌株为LMG 21535T = AS 1.3089T。
