1Institut Pasteur in New Caledonia, Institut Pasteur International Network, Leptospirosis Research and Expertise Unit, Noumea, New Caledonia.
2Institut Pasteur Montevideo, Bioinformatics Unit, Uruguay.
Microb Genom. 2018 Jan;4(1). doi: 10.1099/mgen.0.000144. Epub 2018 Jan 3.
Despite recent advances in our understanding of the genomics of members of the genus Leptospira, little is known on how virulence has emerged in this heterogeneous bacterial genus as well as on the lifestyle of pathogenic members of the genus Leptospira outside animal hosts. Here, we isolated 12 novel species of the genus Leptospira from tropical soils, significantly increasing the number of known species to 35 and finding evidence of highly unexplored biodiversity in the genus. Extended comparative phylogenomics and pan-genome analyses at the genus level by incorporating 26 novel genomes, revealed that, the traditional leptospiral 'pathogens' cluster, as defined by their phylogenetic position, can be split in two groups with distinct virulence potential and accessory gene patterns. These genomic distinctions are strongly linked to the ability to cause or not severe infections in animal models and humans. Our results not only provide new insights into virulence evolution in the members of the genus Leptospira, but also lay the foundations for refining the classification of the pathogenic species.
尽管我们最近对钩端螺旋体属成员的基因组学有了更多的了解，但对于毒力是如何在这个异质的细菌属中出现的，以及致病性钩端螺旋体属成员在动物宿主之外的生活方式，我们知之甚少。在这里，我们从热带土壤中分离出 12 种新型钩端螺旋体属，使已知物种的数量显著增加到 35 种，并发现该属中存在高度未开发的生物多样性的证据。通过整合 26 个新基因组，在属水平上进行扩展的比较系统发生基因组学和泛基因组分析表明，传统上根据其系统发育位置定义的“病原体”钩端螺旋体属聚类，可以分为两组，具有不同的毒力潜力和辅助基因模式。这些基因组差异与在动物模型和人类中引起或不引起严重感染的能力密切相关。我们的研究结果不仅为钩端螺旋体属成员的毒力进化提供了新的见解，而且为完善致病性物种的分类奠定了基础。
