Castillo Daniel, Donati Valentina L, Jørgensen Jóhanna, Sundell Krister, Dalsgaard Inger, Madsen Lone, Wiklund Tom, Middelboe Mathias
Marine Biological Section, Department of Biology, University of Copenhagen, 3000 Helsingør, Denmark.
Instituto de Investigación Interdisciplinar en Ciencias Biomédicas SEK (I3CBSEK), Universidad SEK, Santiago 7520317, Chile.
Microorganisms. 2021 Aug 3;9(8):1658. doi: 10.3390/microorganisms9081658.
The fish pathogen is currently one of the main pathogenic bacteria hampering the productivity of salmonid farming worldwide. Although putative virulence determinants have been identified, the genetic basis for variation in virulence of is not fully understood. In this study, we analyzed whole-genome sequences of a collection of 25 isolates from Baltic Sea countries and compared genomic information with a previous determination of their virulence in juvenile rainbow trout. The results revealed a conserved population of that were consistently present across the Baltic Sea countries, with no clear association between genomic repertoire, phylogenomic, or gene distribution and virulence traits. However, analysis of the entire genome of four isolates by hybrid assembly provided an unprecedented resolution for discriminating even highly related isolates. The results showed that isolates with different virulence phenotypes harbored genetic variances on a number of consecutive leucine-rich repeat (LRR) proteins, repetitive motifs in gliding motility-associated protein, and the insertion of transposable elements into intergenic and genic regions. Thus, these findings provide novel insights into the genetic variation of these elements and their putative role in the modulation of virulence.
这种鱼类病原体是目前阻碍全球鲑鱼养殖生产力的主要病原菌之一。尽管已经确定了假定的毒力决定因素，但对于其毒力变异的遗传基础尚未完全了解。在本研究中，我们分析了来自波罗的海国家的25株该病原菌分离株的全基因组序列，并将基因组信息与之前对它们在幼年虹鳟鱼中毒力的测定结果进行了比较。结果显示，在波罗的海国家中存在一个保守的该病原菌群体，其基因组组成、系统基因组学或基因分布与毒力特征之间没有明显关联。然而，通过混合组装对4株该病原菌分离株的全基因组进行分析，为区分甚至高度相关的分离株提供了前所未有的分辨率。结果表明，具有不同毒力表型的分离株在多个连续的富含亮氨酸重复（LRR）蛋白、滑行运动相关蛋白中的重复基序以及转座元件插入基因间和基因区域方面存在遗传差异。因此，这些发现为这些元件的遗传变异及其在调节该病原菌毒力中的假定作用提供了新的见解。
