Comparative Genomics of Tenacibaculum dicentrarchi and “Tenacibaculum finnmarkense” Highlights Intricate Evolution of Fish-Pathogenic Species

• Published in: Genome biology and evolution Vol. 10; no. 2; pp. 452 - 457
• Main Authors: Bridel, Sébastien, Olsen, Anne-Berit, Nilsen, Hanne, Bernardet, Jean-François, Achaz, Guillaume, Avendaño-Herrera, Ruben, Duchaud, Eric
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.02.2018; Society for Molecular Biology and Evolution
• Subjects: Animals; Fish Diseases - microbiology; Fishes - microbiology; Flavobacteriaceae Infections - veterinary; Genome Report; Genome, Bacterial; Genomics; Life Sciences; Phylogeny; Tenacibaculum - genetics; genomes; tenacibaculosis; evolution; virulence; fish pathogens; Tenacibaculum
• ISSN: 1759-6653; 1759-6653
• DOI: 10.1093/gbe/evy020

Abstract The genus Tenacibaculum encompasses several species pathogenic for marine fish. Tenacibaculum dicentrarchi and “Tenacibaculum finnmarkense” (Quotation marks denote species that have not been validly named.) were retrieved from skin lesions of farmed fish such as European sea bass or Atlantic salmon. They cause a condition referred to as tenacibaculosis and severe outbreaks and important fish losses have been reported in Spanish, Norwegian, and Chilean marine farms. We report here the draft genomes of the T. dicentrarchi and “T. finnmarkense” type strains. These genomes were compared with draft genomes from field isolates retrieved from Chile and Norway and with previously published Tenacibaculum genomes. We used Average Nucleotide Identity and core genome-based phylogeny as a proxy index for species boundary delineation. This work highlights evolution of closely related fish-pathogenic species and suggests that homologous recombination likely contributes to genome evolution. It also corrects the species affiliation of strain AYD7486TD claimed by Grothusen et al. (2016).