Umbribacter vaginalis gen. nov., sp. nov.: novel bacterium isolated from the human vagina.

Gram-variable obligately anaerobic novel bacteria DNF00809 and PR-HUZ-602407-17 were isolated from vaginal fluid samples from women with bacterial vaginosis (BV) in two independent studies conducted in different laboratories. They each displayed ≥99.9% 16S rRNA gene sequence identity to the uncultured bacterial clone sequence AY738656 designated as Eggerthella-like vaginal bacterium (ELVB) and shared 100% 16S rRNA gene sequence identity with each other. Studies using molecular bacterial identification have associated ELVB sequences with BV, higher risk for human immunodeficiency virus acquisition and development of pelvic inflammatory disease in women. Given the clinical significance of this bacterium, we characterized the novel bacterium designated DNF00809T using biochemical, genotypic and phylogenetic analyses. DNF00809T was a coccobacillus that was non-motile, non-spore forming, asaccharolytic, proteolytic and indole negative. Fatty acid methyl ester analysis for DNF00809T indicated C14 : 0, C16 : 0, C16 : 0 dimethyl acetal and C18 : 1 cis9 to be the major fatty acids. Whole genomic DNA G+C content was 46.1 mol%. Phylogenetic and phylogenomic analyses indicate that DNF00809T represents a novel genus and novel species within the Eggerthellaceae family. We propose the name Umbribacter vaginalis gen. nov., sp. nov. with DNF00809T representing the type strain of this species (=DSM 118866T=CCUG77988T).