Department of Pediatrics, Taoyuan General Hospital, Ministry of Health and Welfare, No. 1492, Zhongshan Rd., Taoyuan District, Taoyuan, 330, Taiwan (R.O.C.).
Department of Biotechnology, Ming Chuan University, No. 5, De-Ming Rd., Guishan District, Taoyuan, 330, Taiwan, R.O.C.
Curr Microbiol. 2024 Jul 29;81(9):286. doi: 10.1007/s00284-024-03806-6.
Streptococcus spp. are important opportunistic pathogen of bacteremia in both immunocompetent and immunosuppressed patients. A streptococcal strain, designated ST2, was isolated from the blood specimen of a bacteremic patient. Comparative analyses of 16S rRNA, rpoB and groEL gene sequences demonstrated that the novel strain ST2 is a member of the genus Streptococcus. Based on of 16S rRNA gene sequence similarities, the type strains of Streptococcus (S.) parasanguinis (99.2%), S. ilei (98.8%), S. oralis subsp. oralis (97.6%), S. australis (97.5%) and S. sanguinis (97.5%) were the closest neighbours to strain ST2. The housekeeping gene sequences (rpoB and groEL) similarities of strain ST2 to these closely related type strains were 80.4-97.4%, respectively. The complete draft genome of strain ST2 consisted of 2,155,906 bp with a G + C content of 42.0%. Strain ST2 has an average nucleotide identity (ANI) value of 94.1 and 81.3% with S. parasanguinis ATCC 15912 and S. ilei I-G2, respectively. The highest in silico DNA-DNA hybridization value with respect to the closest species S. parasanguinis was 55.6%, below the species cut-off of 70% hybridization. The primary cellular fatty acids of strain ST2 were C, C ω9c, C and C. Based on biochemical criteria and molecular genetic evidence, it is proposed that strain ST2 be assigned to a new species of the genus Streptococcus as Streptococcus taoyuanensis sp. nov. The type strain of Streptococcus taoyuanensis is ST2 (=NBRC 115928 = BCRC 81374) as the type strain.
链球菌属是免疫功能正常和免疫抑制患者菌血症的重要机会性病原体。从一名菌血症患者的血液标本中分离到一株链球菌菌株，命名为 ST2。16S rRNA、rpoB 和 groEL 基因序列的比较分析表明，新型 ST2 菌株是链球菌属的一个成员。根据 16S rRNA 基因序列相似性，副血链球菌（S. parasanguinis）（99.2%）、S. ilei（98.8%）、口腔链球菌口腔亚种（S. oralis subsp. oralis）（97.6%）、澳大利亚链球菌（S. australis）（97.5%）和 S. sanguinis（97.5%）的模式菌株与 ST2 菌株最为接近。ST2 菌株与这些密切相关的模式菌株的看家基因序列（rpoB 和 groEL）相似性分别为 80.4-97.4%。ST2 菌株的全基因组草图由 2155906bp 组成，G+C 含量为 42.0%。ST2 菌株与副血链球菌 ATCC 15912 和 S. ilei I-G2 的平均核苷酸同一性（ANI）值分别为 94.1%和 81.3%。与最接近的种副血链球菌的最高体外 DNA-DNA 杂交值为 55.6%，低于 70%杂交的种切值。ST2 菌株的主要细胞脂肪酸为 C、C ω9c、C 和 C。基于生化标准和分子遗传学证据，建议将 ST2 菌株归为链球菌属的一个新种，命名为桃园链球菌（Streptococcus taoyuanensis）sp. nov.。桃园链球菌的模式菌株为 ST2（=NBRC 115928=BCRC 81374）。
