title: Complete genome sequence of the fish pathogen Flavobacterium branchiophilum.
abstract: Members of the genus Flavobacterium occur in a variety of ecological niches and represent an interesting diversity of lifestyles. Flavobacterium branchiophilum is the main causative agent of bacterial gill disease, a severe condition affecting various cultured freshwater fish species worldwide, in particular salmonids in Canada and Japan. We report here the complete genome sequence of strain FL-15 isolated from a diseased sheatfish (Silurus glanis) in Hungary. The analysis of the F. branchiophilum genome revealed putative mechanisms of pathogenicity strikingly different from those of the other, closely related fish pathogen Flavobacterium psychrophilum, including the first cholera-like toxin in a non-Proteobacteria and a wealth of adhesins. The comparison with available genomes of other Flavobacterium species revealed a small genome size, large differences in chromosome organization, and fewer rRNA and tRNA genes, in line with its more fastidious growth. In addition, horizontal gene transfer shaped the evolution of F. branchiophilum, as evidenced by its virulence factors, genomic islands, and CRISPR (clustered regularly interspaced short palindromic repeats) systems. Further functional analysis should help in the understanding of host-pathogen interactions and in the development of rational diagnostic tools and control strategies in fish farms.
authors.affiliation: Institut Pasteur, Microbial Evolutionary Genomics, Département Génomes et Génétique, F-75015 Paris, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Touchon
authors.forename: Paul
authors.initials: P
authors.lastname: Barbier
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Bernardet
authors.forename: Valentin
authors.initials: V
authors.lastname: Loux
authors.forename: Benoit
authors.initials: B
authors.lastname: Vacherie
authors.forename: Valérie
authors.initials: V
authors.lastname: Barbe
authors.forename: Eduardo P C
authors.initials: EP
authors.lastname: Rocha
authors.forename: Eric
authors.initials: E
authors.lastname: Duchaud
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics; D000818:Animals; D001427:Bacterial Toxins / Q000235:genetics; D002397:Catfishes / Q000382:microbiology; D004269:DNA, Bacterial / Q000737:chemistry* / Q000235:genetics*; D005393:Fish Diseases / Q000382:microbiology; D005417:Flavobacterium / Q000235:genetics* / Q000302:isolation & purification; D023061:Gene Order; D022761:Gene Transfer, Horizontal; D016680:Genome, Bacterial; D006814:Hungary; D008969:Molecular Sequence Data; D012329:RNA, Bacterial / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D012343:RNA, Transfer / Q000235:genetics; D017422:Sequence Analysis, DNA; D037521:Virulence Factors / Q000235:genetics
chemical_list: D018829:Adhesins, Bacterial; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D012329:RNA, Bacterial; D012335:RNA, Ribosomal; D037521:Virulence Factors; D012343:RNA, Transfer