Chryseobacterium piscicola sp. nov., isolated from diseased salmonid fish

Eight bacterial strains isolated from diseased rainbow trout (n=5) and Atlantic salmon (n=3) were characterized by phenotypic and molecular taxonomic methods. The isolates were negative for the Gram-reaction, non-motile, rod-shaped and catalase- and oxidase-positive. Colonies on solid media were yellow, smooth, shiny and circular with regular edges. Growth occurred at 4-28 degrees C (optimum, 15 degrees C) and with 0-3 % NaCl (optimum, 0.5 %). Analysis of the 16S rRNA gene sequence allocated the micro-organisms to the genus Chryseobacterium, with Chryseobacterium soldanellicola PSD1-4(T) and Chryseobacterium soli JS6-6(T) as their closest relatives (96.9 and 97.1 % sequence similarity, respectively). The levels of DNA-DNA hybridization towards these nearest phylogenetic neighbours were below 17.1 %. The DNA G+C contents of strains VQ-6316s(T) and VQ-4836s were 32.5 and 32.3 mol%, respectively. The predominant menaquinone was MK-6 and the major fatty acids were iso-C(15 : 0), anteiso-C(15 : 0), iso-C(17 : 1)omega9c, iso-C(17 : 0) 3-OH and summed feature 3 (comprising C(16 : 1)omega7c and/or C(16 : 1)omega7t and/or iso-C(15 : 0) 2-OH). The eight isolates were classified as representatives of a novel species, Chryseobacterium piscicola sp. nov., with strain VQ-6316s(T) (=CECT 7357(T)=DSM 21068(T)) as the type strain.