Pan genome and CRISPR analyses of the bacterial fish pathogen Moritella viscosa

BMC Genomics

Research Article

Erik Hjerde¹  Terje Klemetsen¹  Nils Peder Willassen²  Christian Karlsen³ 

[1] Department of Chemistry, Faculty of Science and Technology, University of Tromsø, N-9037, Tromsø, Norway;Department of Chemistry, Faculty of Science and Technology, University of Tromsø, N-9037, Tromsø, Norway;The Norwegian Structural Biology Centre, University of Tromsø, N-9037, Tromsø, Norway;Department of Food Safety and Infection Biology, Norwegian University of Life Sciences (NMBU), Pb 8146 Dep., 0033, Oslo, Norway;Present address: Nofima AS, Division of Aquaculture, PO Box 210, N-1431, Ås, Norway;

关键词: Moritella viscosa;    CRISPR-Cas;    Mobile genetic element;    Atlantic salmon pathogen;   

DOI  :  10.1186/s12864-017-3693-7

 received in 2017-02-02, accepted in 2017-04-06,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundWinter-ulcer Moritella viscosa infections continue to be a significant burden in Atlantic salmon (Salmo salar L.) farming. M. viscosa comprises two main clusters that differ in genetic variation and phenotypes including virulence. Horizontal gene transfer through acquisition and loss of mobile genetic elements (MGEs) is a major driving force of bacterial diversification. To gain insight into genomic traits that could affect sublineage evolution within this bacterium we examined the genome sequences of twelve M. viscosa strains. Matches between M. viscosa clustered, regularly interspaced, short palindromic, repeats and associated cas genes (CRISPR-Cas) were analysed to correlate CRISPR-Cas with adaptive immunity against MGEs.ResultsThe comparative genomic analysis of M. viscosa isolates from across the North Atlantic region and from different fish species support delineation of M. viscosa into four phylogenetic lineages. The results showed that M. viscosa carries two distinct variants of the CRISPR-Cas subtype I-F systems and that CRISPR features follow the phylogenetic lineages. A subset of the spacer content match prophage and plasmid genes dispersed among the M. viscosa strains. Further analysis revealed that prophage and plasmid-like element distribution were reflected in the content of the CRISPR-spacer profiles.ConclusionsOur data suggests that CRISPR-Cas mediated interactions with MGEs impact genome properties among M. viscosa, and that patterns in spacer and MGE distributions are linked to strain relationships.

【 授权许可】

CC BY   
© The Author(s). 2017