Vagococcus luciliae sp. nov., isolated from the common green bottle fly Lucilia sericata.

Abstract

The genus Vagococcus belongs to the family Enterococcaceae (order Lactobacillales) and is closely related to the genus Enterococcus. Currently, 19 species of the genus have been validly named. In this study, we isolated strain G314FT from the common green bottle fly Lucilia sericata collected in Germany. Sequencing of its almost-complete 16S rRNA gene revealed that the isolate belongs to the genus Vagococcus, being closely related to Vagococcus bubulae SS1994T with high sequence identity (99.50 %), followed by Vagococcus martis D7T301T (98.86 %), Vagococcus vulneris SS1995T (98.71 %), Vagococcus teuberi DSM 21459T (98.64 %), Vagococcus silagei 2B-2T (98.64 %) and Vagococcus penaei CD276T (98.64 %). Genome sequencing of strain G314FT was performed by a combination of Illumina and Oxford Nanopore technology, yielding a circular genome with a size of 2 139 468 bp and an 11 kb plasmid. Average nucleotide identity and digital DNA-DNA hybridization values were calculated between G314FT and its closest-related taxa, and found to be <91 % and <40 %, respectively, thus strongly supporting that strain G314FT represents a novel species of the genus Vagococcus. Phylogenetic and core protein-based phylogenomic trees revealed that G314FT was closely related to a group of three species, V. bubulae SS1994T, V. martis D7T301T and V. teuberi DSM 21459T. Comparatively, the genome of G314FT is the smallest in the group of the four related species, and the biochemical pathway comparison using BlastKOALA revealed that G314FT has lost some amino acid biosynthetic proteins; however, it has gained enzymes for carbohydrate metabolism. Phenotypically, G314FT was consistent with other species of the genus Vagococcus including a negative catalase reaction and non-motility. Using the polyphasic approach, our data supports that the isolate represents a new species, for which we propose the name Vagococcus luciliae G314FT (=DSM 112651T= CCM 9164T).