title: Multilocus sequence analysis of the marine bacterial genus Tenacibaculum suggests parallel evolution of fish pathogenicity and endemic colonization of aquaculture systems.
abstract: The genus Tenacibaculum, a member of the family Flavobacteriaceae, is an abundant component of marine bacterial ecosystems that also hosts several fish pathogens, some of which are of serious concern for marine aquaculture. Here, we applied multilocus sequence analysis (MLSA) to 114 representatives of most known species in the genus and of the worldwide diversity of the major fish pathogen Tenacibaculum maritimum. Recombination hampers precise phylogenetic reconstruction, but the data indicate intertwined environmental and pathogenic lineages, which suggests that pathogenicity evolved independently in several species. At lower phylogenetic levels recombination is also important, and the species T. maritimum constitutes a cohesive group of isolates. Importantly, the data reveal no trace of long-distance dissemination that could be linked to international fish movements. Instead, the high number of distinct genotypes suggests an endemic distribution of strains. The MLSA scheme and the data described in this study will help in monitoring Tenacibaculum infections in marine aquaculture; we show, for instance, that isolates from tenacibaculosis outbreaks in Norwegian salmon farms are related to T. dicentrarchi, a recently described species.
authors: Virologie et Immunologie Moléculaires UR892, INRA, Jouy-en-Josas, France Mathémathique Informatique et Génome UR1077, INRA, Jouy-en-Josas, France.
authors: Christophe
authors: C
authors: Habib
authors: Virologie et Immunologie Moléculaires UR892, INRA, Jouy-en-Josas, France.
authors: Armel
authors: A
authors: Houel
authors: Virologie et Immunologie Moléculaires UR892, INRA, Jouy-en-Josas, France.
authors: Aurélie
authors: A
authors: Lunazzi
authors: Virologie et Immunologie Moléculaires UR892, INRA, Jouy-en-Josas, France.
authors: Jean-François
authors: JF
authors: Bernardet
authors: National Veterinary Institute Bergen, Bergen, Norway.
authors: Anne Berit
authors: AB
authors: Olsen
authors: National Veterinary Institute Bergen, Bergen, Norway.
authors: Hanne
authors: H
authors: Nilsen
authors: Departamento de Microbiología y Parasitología, Facultad de Biología and Instituto de Acuicultura, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
authors: Alicia E
authors: AE
authors: Toranzo
authors: Departamento de Microbiología y Parasitología, Facultad de Biología and Instituto de Acuicultura, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
authors: Nuria
authors: N
authors: Castro
authors: Mathémathique Informatique et Génome UR1077, INRA, Jouy-en-Josas, France.
authors: Pierre
authors: P
authors: Nicolas
authors: Virologie et Immunologie Moléculaires UR892, INRA, Jouy-en-Josas, France eric.duchaud@jouy.inra.fr.
authors: Eric
authors: E
authors: Duchaud
mesh_terms: D000818:Animals; D017756:Aquaculture; D016000:Cluster Analysis; D005393:Fish Diseases / Q000382:microbiology*; D045826:Flavobacteriaceae Infections / Q000382:microbiology / Q000662:veterinary*; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D013559:Symbiosis; D060493:Tenacibaculum / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D014774:Virulence