Fayad Nancy, Koné Klèma Marcel, Gillis Annika, Mahillon Jacques
Laboratory of Food and Environmental Microbiology, Earth and Life Institute, Louvain-la-Neuve, Belgium.
School of Pharmacy, Lebanese American University, Byblos, Lebanon.
Front Microbiol. 2021 Dec 9;12:789929. doi: 10.3389/fmicb.2021.789929. eCollection 2021.
is the thermotolerant representative of the group. This group, also known as , comprises both beneficial and pathogenic members and includes psychrotolerant and thermotolerant species. was originally recovered from a fatal outbreak in France in 1998. This species forms a remote cluster from the group members and reliably contains the gene, coding for a cytotoxic variant of cytotoxin K. Although this species was originally thought to be homogenous, intra-species diversity has been recently described with four clades, six random amplified polymorphic DNA (RAPD) patterns, and 11 plasmids profiles. This study aimed to get new insights into the genomic diversity of and to decipher the underlying chromosomal and plasmidial variations among six representative isolates through whole genome sequencing (WGS). Among the six sequenced strains, four fitted the previously described genomic clades A and D, while the remaining two constituted new distinct branches. As for the plasmid content of these strains, three large plasmids were putatively conjugative and three small ones potentially mobilizable, harboring coding genes for putative leaderless bacteriocins. Mobile genetic elements, such as prophages, Insertion Sequences (IS), and repeats () greatly contributed to the diversity. As for IS elements and , IS and were the most abundant elements and, along with the group II intron , were found in all analyzed . strains. When compared to other strains, the type-strain NVH 391-98 displayed a relatively low number of IS. Our results shed new light on the contribution of mobile genetic elements to the genome plasticity of and their potential role in horizontal gene transfer.
是该菌群的耐热代表菌。这个菌群，也被称为 ，包含有益菌和致病菌成员，包括耐冷菌和耐热菌物种。 最初是从1998年法国的一次致命疫情中分离出来的。该物种与 菌群成员形成一个较远的聚类，并且可靠地含有 基因，该基因编码细胞毒素K的细胞毒性变体。尽管该物种最初被认为是同质的，但最近已描述了其种内多样性，包括四个进化枝、六种随机扩增多态性DNA（RAPD）模式和11种质粒图谱。本研究旨在深入了解 的基因组多样性，并通过全基因组测序（WGS）来解读六个代表性分离株之间潜在的染色体和质粒变异。在六个测序菌株中，四个符合先前描述的基因组进化枝A和D，而其余两个构成新的独特分支。至于这些菌株的质粒含量，三个大质粒被推测为可接合的，三个小质粒可能是可移动的，携带假定的无信号肽细菌素的编码基因。移动遗传元件，如前噬菌体、插入序列（IS）和 重复序列（ ）对 的多样性有很大贡献。至于IS元件和 ，IS 和 是最丰富的元件，并且与II类内含子 一起，在所有分析的 菌株中都有发现。与其他 菌株相比，模式菌株NVH 391-98显示出相对较少的IS。我们的结果为移动遗传元件对 的基因组可塑性的贡献及其在水平基因转移中的潜在作用提供了新的见解。
