Department of Epidemiology, School of Public Health, Shanxi Medical University, Taiyuan 030001, PR China.
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, PR China.
Int J Syst Evol Microbiol. 2024 Oct;74(10). doi: 10.1099/ijsem.0.006531.
Four anaerobic, Gram-stain-positive, non-motile, non-sporulating rod-shaped bacterial strains (R7, R21, R22 and R25) were isolated from the intestinal contents of plateau pika () collected from the Qinghai-Tibet Plateau, PR China. The four isolates grew at between 25 and 42 °C (optimally at 35-37 °C), and with 0.3-3.3% NaCl (w/v) [optimum, 1.3% (w/v)]. Adding l-arginine to the medium could promote their growth. Strains R7 and R21 were most closely related to B7 (97.48% 16S rRNA gene sequence similarity). Strains R25 and R22 were most closely related to e DSM 19450 (98.25% 16S rRNA gene sequence similarity). The genome sequences of R7 and R25 were 2.89 and 2.90 Mb in size with 63.6 and 62.8 mol% DNA G+C contents, respectively. Phylogenetic analysis based on 16S rRNA gene sequences and core genes revealed that R7 and R21 were most closely related to B7 and DSM 19490, whereas R25 and R22 were most closely related to DSM 19450 and ResAG-91. R7, R25 and the closely related species had average nucleotide identity (ANI) values of 81.9-83.2% as well as digital DNA-DNA hybridisation (dDDH) values between 27.3 and 27.9%, which clearly indicated that they represent two novel species within the genus . For R7 and R25, meso-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan, and the whole cell sugars included galactose, glucose and ribose. On the basis of these results, we propose that strains R7 and R25 represent two novel species of the genus namely sp. nov. and sp. nov., respectively. The type strains are R7 (=GDMCC 1.4459=KCTC 25860) and R25 (=GDMCC 1.4458=KCTC 25861).
从中国青藏高原采集的高原兔肠道内容物中分离到四株厌氧、革兰氏阳性、非运动、非孢子形成的杆状细菌菌株（R7、R21、R22 和 R25）。这四株菌在 25 到 42°C 之间生长（最佳温度为 35-37°C），并在 0.3-3.3% NaCl（w/v）[最佳，1.3%（w/v）]下生长。在培养基中添加 l-精氨酸可以促进它们的生长。菌株 R7 和 R21 与 B7（97.48% 16S rRNA 基因序列相似性）最为密切相关。菌株 R25 和 R22 与 e DSM 19450（98.25% 16S rRNA 基因序列相似性）最为密切相关。R7 和 R25 的基因组序列大小分别为 2.89 和 2.90 Mb，DNA G+C 含量分别为 63.6 和 62.8 mol%。基于 16S rRNA 基因序列和核心基因的系统发育分析表明，R7 和 R21 与 B7 和 DSM 19490 最为密切相关，而 R25 和 R22 与 DSM 19450 和 ResAG-91 最为密切相关。R7、R25 及其密切相关的种属的平均核苷酸同一性（ANI）值为 81.9-83.2%，数字 DNA-DNA 杂交（dDDH）值在 27.3-27.9%之间，这清楚地表明它们代表了属内的两个新种 。对于 R7 和 R25，meso-二氨基庚二酸是细胞壁肽聚糖中的诊断二氨基氨基酸，全细胞糖包括半乳糖、葡萄糖和核糖。基于这些结果，我们提出菌株 R7 和 R25 代表 属的两个新种，分别命名为 sp. nov. 和 sp. nov.。模式菌株为 R7（=GDMCC 1.4459=KCTC 25860）和 R25（=GDMCC 1.4458=KCTC 25861）。
