Flavobacterium turcicum sp. nov. and Flavobacterium kayseriense sp. nov. isolated from farmed rainbow trout in Turkey

Abstract

During a study on culturable microorganisms from fish farms, four yellow-pigmented gram negative, rod shaped isolates, F-47(T), F-339(T), F-380 and F-400, were recovered from rainbow trout samples exhibiting clinical signs. Based on 16S rRNA gene sequence analysis, the strains were identified as members of the genus Flavobacterium. Strains F-47(T) and F-380 shared the highest 16S rRNA gene sequence identity level of 97.6% with the type strain of Flavobacterium frigoris DSM 15719(T) while strains F-339(T) and F-400 shared the highest identity level of 97.6% with the type strain of F. caseinilyticum AT-3-2(T). A polyphasic taxonomic approach including phenotypic and genomic characterization as well as whole-cell MALDI-TOF mass spectrometry analyses was employed to ascertain the taxonomic position of the strains within the genus Flavobacterium. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) analyses between strains F-47(T), F-339(T) and their close neighbours F. frigoris DSM 15719(T) and F. caseinilyticum AT-3-2(T), respectively, confirmed that both strains represent novel species in the genus Flavobacterium. The DNA G+C contents of the strains F-47(T) and F-339(T) are 34.3% and 35.3%, respectively. It can be concluded on the basis of polyphasic characterization as well as pairwise genome comparisons that the strains F-47(T) and F-339(T) represent two novel species within the genus Flavobacterium, for which Flavobacterium kayseriense sp. nov. F-47(T) (=JCM 34195(T)=KCTC 82255(T)) and Flavobacterium turcicum sp. nov. F-339(T) (=JCM 34202(T)=KCTC 82262(T)) are proposed, respectively.