Ongoing diversification of the global fish pathogen Piscirickettsia salmonis through genetic isolation and transposition bursts

  • The management of bacterial pathogens remains a key challenge of aquaculture. The marine gammaproteobacterium Piscirickettsia salmonis is the etiological agent of piscirickettsiosis and causes multi-systemic infections in different salmon species, resulting in considerable mortality and substantial commercial losses. Here, we elucidate its global diversity, evolution, and selection during human interventions. Our comprehensive analysis of 73 closed, high quality genome sequences covered strains from major outbreaks and was supplemented by an analysis of all P. salmonis 16S rRNA gene sequences and metagenomic reads available in public databases. Genome comparison showed that Piscirickettsia comprises at least three distinct, genetically isolated species of which two showed evidence for continuing speciation. However, at least twice the number of species exist in marine fish or seawater. A hallmark of Piscirickettsia diversification is the unprecedented amount and diversity ofThe management of bacterial pathogens remains a key challenge of aquaculture. The marine gammaproteobacterium Piscirickettsia salmonis is the etiological agent of piscirickettsiosis and causes multi-systemic infections in different salmon species, resulting in considerable mortality and substantial commercial losses. Here, we elucidate its global diversity, evolution, and selection during human interventions. Our comprehensive analysis of 73 closed, high quality genome sequences covered strains from major outbreaks and was supplemented by an analysis of all P. salmonis 16S rRNA gene sequences and metagenomic reads available in public databases. Genome comparison showed that Piscirickettsia comprises at least three distinct, genetically isolated species of which two showed evidence for continuing speciation. However, at least twice the number of species exist in marine fish or seawater. A hallmark of Piscirickettsia diversification is the unprecedented amount and diversity of transposases which are particularly active in subgroups undergoing rapid speciation and are key to the acquisition of novel genes and to pseudogenization. Several group-specific genes are involved in surface antigen synthesis and may explain the differences in virulence between strains. However, the frequent failure of antibiotic treatment of piscirickettsiosis outbreaks cannot be explained by horizontal acquisition of resistance genes which so far occurred only very rarely. Besides revealing a dynamic diversification of an important pathogen, our study also provides the data for improving its surveillance, predicting the emergence of novel lineages, and adapting aquaculture management, and thereby contributes towards the sustainability of salmon farming.show moreshow less

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Author:Isabel Schober, Boyke Bunk, Gabriela Carril, Heike M. Freese, Nicolás Ojeda, Thomas Riedel, Jan P. Meier-KolthoffORCiDGND, Markus Göker, Cathrin Spröer, Patricio A. Flores-Herrera, Guillermo Nourdin-Galindo, Fernando Gómez, Constanza Cárdenas, Felipe Vásquez-Ponce, Alvaro Labra, Jaime Figueroa, Jorge Olivares-Pacheco, Ulrich Nübel, Johannes Sikorski, Sergio H. Marshall, Jörg Overmann
URN:urn:nbn:de:bvb:384-opus4-1124008
Frontdoor URLhttps://opus.bibliothek.uni-augsburg.de/opus4/112400
ISSN:1751-7362OPAC
ISSN:1751-7370OPAC
Parent Title (English):The ISME Journal
Publisher:Oxford University Press (OUP)
Place of publication:Oxford
Type:Article
Language:English
Year of first Publication:2023
Publishing Institution:Universität Augsburg
Release Date:2024/03/28
Volume:17
Issue:12
First Page:2247
Last Page:2258
DOI:https://doi.org/10.1038/s41396-023-01531-9
Institutes:Fakultät für Angewandte Informatik
Fakultät für Angewandte Informatik / Institut für Informatik
Fakultät für Angewandte Informatik / Institut für Informatik / Lehrstuhl für Biomedizinische Informatik, Data Mining und Data Analytics
Dewey Decimal Classification:0 Informatik, Informationswissenschaft, allgemeine Werke / 00 Informatik, Wissen, Systeme / 004 Datenverarbeitung; Informatik
Licence (German):CC-BY 4.0: Creative Commons: Namensnennung (mit Print on Demand)