SRUC Veterinary Services, An Lochran, 10 Inverness Campus, Inverness IV2 5NA, UK.
Department of Bacteriology, Animal and Plant Health Agency, Addlestone, KT15 3NB, UK.
Int J Syst Evol Microbiol. 2020 Apr;70(4):2611-2615. doi: 10.1099/ijsem.0.004081. Epub 2020 Mar 11.
Five strains of an unidentified Gram-positive, catalase-negative, chain-forming coccus-shaped organism recovered from sheep in Scotland were characterized using phenotypic and molecular taxonomic methods. Based on morphological and biochemical criteria, the strains were tentatively identified as streptococci but they did not appear to correspond to any recognised species of the genus. Comparative 16S rRNA gene sequencing showed the strains were highly related to each other and confirmed their placement in the genus , with a maximum nucleotide identity of around 97 % to extant species. Best matches were with followed by . Average nucleotide identity and DNA-DNA hybridization values determined from whole-genome sequence were also consistent with the group representing a novel species. Best matches, again seen to , followed by and , were below accepted cut-off values for species delineation. Based on biochemical criteria and molecular genetic evidence, it is proposed that the unknown isolates from sheep be assigned to a new species of the genus as sp. nov. The type strain of is S784/96/1=CCUG 73951=NCTC 14363.
从苏格兰绵羊中分离到的五株未鉴定的革兰阳性、过氧化氢酶阴性、链状球菌状微生物，使用表型和分子分类学方法进行了特征描述。根据形态学和生化标准，这些菌株被初步鉴定为链球菌，但它们似乎与该属的任何已知种都不对应。比较 16S rRNA 基因测序表明，这些菌株彼此高度相关，并且证实它们在属内的位置，与现存物种的核苷酸同一性最高约为 97%。最佳匹配是 ，其次是 。从全基因组序列确定的平均核苷酸同一性和 DNA-DNA 杂交值也与代表新种的组一致。最佳匹配，同样是 ，其次是 和 ，低于种划分的可接受截止值。基于生化标准和分子遗传学证据，建议将绵羊中未知的分离株分配到该属的一个新种 中，即 sp. nov. 。 的模式株为 S784/96/1=CCUG 73951=NCTC 14363。
