Multilocus sequence analysis reveals extensive genetic variety within Tenacibaculum spp. associated with ulcers in sea-farmed fish in Norway

• Published in: Veterinary Microbiology
• Main Authors: Olsen, Anne Berit, Gulla, Snorre, Steinum, Terje, Colquhoun, Duncan J., Nilsen, Hanne K., Duchaud, Éric
• Other Authors: Norwegian Veterinary Institute Oslo ( NVI), Istanbul University, Unité de recherche Virologie et Immunologie Moléculaires (VIM (UR 0892)), Institut National de la Recherche Agronomique (INRA), EU EMIDA ERA-NET project "Control Flavobacteriaceae Infections in European Fish farms" RCN 202834/F40
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: Tenacibaculum; Tenacibaculum dicentrarchi; Atlantic salmon; Wrasse; Skin ulcers; MLSA; [SDV]Life Sciences [q-bio]; Norway
• Online Access: https://hal.inrae.fr/hal-02622553; https://doi.org/10.1016/j.vetmic.2017.04.028

International audience Skin ulcer development in sea-reared salmonids, commonly associated with Tenacibaculum spp., is a significant fish welfare- and economical problem in Norwegian aquaculture. A collection of 89 Tenacibaculum isolates was. subjected to multilocus sequence analysis (MLSA). The isolates were retrieved from outbreaks of clinical disease in farms spread along the Norwegian coast line from seven different fish species over a period of 19 years. MLSA analysis reveals considerable genetic diversity, but allows identification of four main clades. One Glade encompasses isolates belonging to the species T. dicentrarchi, whereas three clades encompass bacteria that likely represent novel, as yet undescribed species. The study identified T. maritimum in lumpsucker, T. ovolyticum in halibut, and has extended the host and geographic range for T. soleae, isolated from wrasse. The overall lack of clonality and host specificity, with some indication of geographical range restriction argue for local epidemics involving multiple strains. The diversity of Tenacibaculum isolates from fish displaying ulcerative disease may complicate vaccine development.