Search

A strain, S-1T was isolated from rainbow trout (Oncorhynchus mykiss) exhibiting clinical symptoms of lens atrophy, inappetence, visual impairment and growth retardation. The strain was identified as representing a member of the genus Shewanella on the basis of the results of 16S rRNA gene sequence analysis. The neighbor-joining phylogenetic tree based on 16S rRNA gene sequences indicated that S-1T clustered with Shewanella putrefaciens JCM 20190T, Shewanella profunda DSM 15900T, and Shewanella hafniensis P010T, sharing 99.3, 98.8 and 87.7% 16S rRNA gene similarities, respectively. A polyphasic taxonomic approach including phenotypic, chemotaxonomic, and genomic characterization was employed to ascertain the taxonomic position of S-1T within the genus Shewanella . The overall genome relatedness indices (OGRI) for S-1T compared with the most closely related type strains S. hafniensis ATCC BAA-1207T, Shewanella baltica NCTC 10735T, S. putrefaciens ATCC 8071T and S. profunda DSM 15900T were calculated as 40.8, 40.1, 28.5 and 27.3% for digital DNA–DNA hybridization (dDDH), and 91.6, 91.0, 86.3 and 85.1% for average nucleotide identity (ANI), respectively. OGRI values between S-1T and its close neighbours confirmed that the strain represents a novel species in the genus Shewanella .The DNA G+C content of the strain is 45.2%. Major fatty acids were C17 : 1ω8c, C15 : 0iso, and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c). The predominant polar lipids were phosphatidylethanolamine, phospholipid, amino-phospholipid and unidentified lipids. The major respiratory quinones were ubiquinone-8, ubiquinone-7 and menaquinone-7. Chemotaxonomic and phylogenomic analyses of this isolate confirmed that the strain represents a novel species for which the name Shewanella oncorhynchi sp. nov. is proposed, with S-1T as the type strain (JCM 34183T= KCTC 82249T).

Two yellow-pigmented isolates, F-60Tand F-392, were isolated from the internal organs of an apparently healthy rainbow trout (Oncorhynchus mykiss). The strains were identified as members of the genusFlavobacteriumbased on the results of 16S rRNA gene sequence analysis. Strains F-60Tand F-392 had the highest 16S rRNA gene sequence identity level of 97.4 % to the type strain ofFlavobacterium crassostreaeLPB0076T. A polyphasic taxonomic approach including phenotypic, chemotaxonomic and genomic characterization was employed to ascertain the taxonomic position of the strains within the genusFlavobacterium. Digital DNA–DNA hybridization (dDDH) and average nucleotide identity based onblast(ANIb) values for strains F-60Tand F-392 were calculated as 100 %. However, dDDH and ANI analyses between the strains and their close neighbours confirmed that both strains represent a novel species in the genusFlavobacterium. The strains shared the highest dDDH and ANIb levels of 23.3 and 77.9%, respectively, with the type strain ofFlavobacterium frigidariumDSM 17623Twhile those values forF. crassostreaeLPB0076Twere obtained as 21.4–21.5 % and 76.3 %. The DNA G+C content of the strains was 34.5 mol%. Chemotaxonomic and phylogenomic analyses of these isolates confirmed that both strains are representatives of a novel species for which the nameFlavobacterium muglaensesp. nov. is proposed, with F-60Tas the type strain (=JCM 34196T=KCTC 82256T).