Oceanivirga miroungae sp. nov., isolated from oral cavity of northern elephant seal (Mirounga angustirostris)

Two independent strains of a Leptotrichia species (ES3154-GLU^T and ES2714_GLU) were isolated from the oral cavity of northern elephant seals (Mirounga angustirostris) that were admitted to The Marine Mammal Centre facilities in California, USA. The strains were isolated from oral swabs by cultivation in PPLO broth supplemented with serum, penicillin and colistin in anaerobic conditions. The strains were Gram-negative, pleomorphic, indole-, oxidase- and catalase-negative, non-spore-forming, non-motile rods/coccobacilli in short chains. The 16S rRNA gene sequence of these strains shared 94.42 % nucleotide similarity with Oceanivirga salmonicida AVG 2115^T but demonstrated ≤86.00-92.50 % nucleotide similarity to the 16S rRNA genes of other species of the family Leptotrichiaceae. The genome was sequenced for strain ES3154-GLU^T. Average nucleotide identity values between strain ES3154-GLU^T and 15 type strain genomes from the family Leptotrichiaceae ranged from 66.74 % vs. Sebaldella termitidis to 73.35 % vs. O. salmonicida. The whole genome phylogeny revealed that the novel species was most closely related to O. salmonicida AVG 2115^T. This relationship was also confirmed by nucleotide similarity and multilocus phylogenetic analyses employing various housekeeping genes (partial 23S rRNA, rpoB, rpoC, rpoD, polC, adh, gyrA and gyrB genes). Chemotaxonomic and phenotypical features of strain ES3154-GLU^T were in congruence with closely related members of the family Leptotrichiaceae, represented by similar enzyme profiles and fatty acid patterns. MALDI-TOF MS analysis was capable to clearly discriminate strain ES3154-GLU^T from all currently described taxa of the family Leptotrichiaceae. Based on these data, we propose a novel species of the genus Oceanivirga, for which the name Oceanivirga miroungae sp. nov. is proposed with the type strain ES3154-GLU^T (=DSM 109740^T=CCUG 73653^T=ATCC TSD-189^T=NCTC 14411^T) and one representative strain ES2714_GLU. The G+C content is 26.82 %, genome size is 1 356 983 bp.