Zhou Ye, Zhao Jianxin, Ross Paul, Stanton Catherine, Chen Wei, Yang Bo
State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu, PR China.
School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, PR China.
Int J Syst Evol Microbiol. 2025 Feb;75(2). doi: 10.1099/ijsem.0.006674.
Three novel coccoid-shaped strains, designated 21WXBC0057M1, 21WXBC0044M1 and BJSWXB5TM5, were isolated from human breast milk in Wuxi, Jiangsu Province, China. These strains were facultative anaerobes, catalase-negative and Gram-positive. Through a comprehensive analysis of rRNA genes, protein-coding housekeeping genes and genomic phylogeny, we identified these strains as belonging to the genus . Specifically, strain 21WXBC0057M1 was phylogenetically most closely related to strain 21WXBC0044M1 was most closely related to and strain BJSWXB5TM5 displayed similarities to and . The pairwise average nucleotide identity and digital DNA-DNA hybridization values for these three strains were below 95 and 70%, respectively, indicating that they occupied evolutionary branches distinct from all previously validly published species. Distinctive phenotypic characteristics discriminated these novel species from the type strains of their most closely related species. The major cellular fatty acids in the three strains were C and C. Genome annotation and a thorough examination of carbohydrate-active enzyme distribution highlighted the observation that all strains possessed extensive capabilities for carbohydrate metabolism, particularly human milk oligosaccharides utilization. Thus, based on these findings, we proposed the classification of the strains as representing three novel species within the genus sp. nov. (type strain 21WXBC0057M1=GDMCC 1.4126=KCTC 25760), sp. nov. (type strain 21WXBC0044M1= GDMCC 1.4127=KCTC 25762) and sp. nov. (type strain BJSWXB5TM5=GDMCC 1.4130=KCTC 25759).
从中国江苏省无锡市的人母乳中分离出三株新型球状菌株，分别命名为21WXBC0057M1、21WXBC0044M1和BJSWXB5TM5。这些菌株为兼性厌氧菌，过氧化氢酶阴性，革兰氏阳性。通过对rRNA基因、蛋白质编码管家基因和基因组系统发育的综合分析，我们将这些菌株鉴定为属于 属。具体而言，菌株21WXBC0057M1在系统发育上与 菌株关系最为密切，菌株21WXBC0044M1与 关系最为密切，菌株BJSWXB5TM5与 和 显示出相似性。这三株菌株的成对平均核苷酸同一性和数字DNA-DNA杂交值分别低于95%和70%，表明它们占据了与所有先前有效发表的 物种不同的进化分支。独特的表型特征将这些新物种与其最密切相关物种的模式菌株区分开来。这三株菌株中的主要细胞脂肪酸为C 和C。基因组注释和对碳水化合物活性酶分布的全面检查突出了所有菌株都具有广泛的碳水化合物代谢能力，特别是对人乳寡糖的利用这一观察结果。因此，基于这些发现，我们提议将这些菌株分类为代表 属内的三个新物种，即 新种（模式菌株21WXBC0057M1 = GDMCC 1.4126 = KCTC 25760）、 新种（模式菌株21WXBC0044M1 = GDMCC 1.4127 = KCTC 25762）和 新种（模式菌株BJSWXB5TM5 = GDMCC 1.4130 = KCTC 25759）。
