Tenacibaculum finnmarkense sp. nov., a fish pathogenic bacterium of the family Flavobacteriaceae isolated from Atlantic salmon

Abstract

A novel Gram-stain negative, aerobic, non-flagellated, rod-shaped gliding bacterial strain, designated HFJT, was isolated from a skin lesion of a diseased Atlantic salmon (Salmo salar L.) in Finnmark, Norway. Colonies were observed to be yellow pigmented with entire and/or undulating margins and did not adhere to the agar. The 16S rRNA gene sequence showed that the strain belongs to the genus Tenacibaculum (family Flavobacteriaceae, phylum ‘Bacteroidetes’). Strain HFJT exhibits high 16S rRNA gene sequence similarity values to Tenacibaculum dicentrarchi NCIMB 14598T (97.2 %). The strain was found to grow at 2–20 °C and only in the presence of sea salts. The respiratory quinone was identified as menaquinone 6 and the major fatty acids were identified as summed feature 3 (comprising C16:1 ω7c and/or iso-C15:0 2-OH), iso-C15:0, anteiso-C15:0, iso-C15:1 and iso-C15:0 3-OH. The DNA G+C content was determined to be 34.1 mol%. DNA–DNA hybridization and comparative phenotypic and genetic tests were performed with the phylogenetically closely related type strains, T. dicentrarchi NCIMB 14598T and Tenacibaculumovolyticum NCIMB 13127T. These data, as well as phylogenetic analyses, suggest that strain HFJT should be classified as a representative of a novel species in the genus Tenacibaculum, for which the name Tenacibaculum finnmarkense sp. nov. is proposed; the type strain is HFJ T = (DSM 28541T = NCIMB 42386T).

The environmental and host‐associated bacterial microbiota of Arctic seawater‐farmed Atlantic salmon with ulcerative disorders

“…That Tenacibaculum isolates from Atlantic salmon do not grow on blood agar supplemented with NaCl is recently demonstrated by Småge et al . (). The representative colonies sequenced represented Moritella , Photobacterium and two Aliivibrio phenotypes.…”

“…Tenacibaculum finnmarkense is a recently suggested novel fish pathogenic species in which strain Tsp.5 belong (Småge et al . ). The study of Småge et al .…”

“…The study of Småge et al . () indicates that multiple species of the Tenacibaculum genus are isolated from Atlantic salmon, similar to Vibrio and Aliivibrio ( Benediktsdottir et al . , ; Lunder et al .…”

“…Tenacibaculum produce skin ulcers in scarified areas and co-infect ulcers already induced by M. viscosa (Olsen et al 2011). A recent study showed a phylogenetic diversity within Tenacibaculum isolated from Norwegian Atlantic salmon and Atlantic cod, and that isolates clustering to the Tenacibaculum finnmarkense clade were pathogenic to Atlantic salmon (Sm age et al 2015). Cutaneous mucus is the first physical and chemical barrier of fish that is protective against pathogenic microorganisms (Shephard 1994).…”

Repeated evolutionary transitions of flavobacteria from marine to non‐marine habitats

“…Likewise, non-marine flavobacteria are ubiquitous in soil and often strongly enriched in the rhizosphere (Bodenhausen et al, 2013) and freshwater lakes and streams (Kim et al, 2009;Shin et al, 2017). Moreover, several flavobacterial lineages are known pathogens, such as the non-marine species Elizabethkingia meningosepticum causing meningitis in neonates (Ceyhan and Celik, 2011) and Flavobacterium psychrophilum threatening freshwater fishes (Duchaud et al, 2007), and the marine species Tenacibaculum maritimum causing marine fish diseases (Småge et al, 2016). Adaptation to such diverse ecological niches indicates high genomic plasticity in Flavobacteriaceae.…”