Anaerococcus ihuae sp. nov. and Mediannikoviicoccus vaginalis gen. nov., sp. nov., two new bacteria isolated from human vaginal samples

Abstract

Strains Marseille-Q5893 (= CSUR Q5893 = CECT 30496) and Marseille-Q5883 (= CSUR Q5883 = CECT 30497) were isolated from vaginal samples using the culturomics approach. The 16S rRNA gene sequences of each strain were sequenced and then compared by BLASTn to the NCBI database. Strains Marseille-Q5893 and Marseille-Q5883 were most closely related to Anaerococcus obesiensis and Finegoldia magna, with identities of 98.5% and 90.0%, respectively. Strain Marseille-Q5893 is strictly anaerobic, while strain Marseille-Q5883 is facultative anaerobic. Both strains are Gram-positive, coccus-shaped, oxidase- and catalase-negative. The most abundant fatty acid for both strains is hexadecanoic acid, followed by 9-octadecenoic acid and tetradecanoic acid. Strain Marseille-Q5893 has a genome size of 1,831,271 bp with a G+C content of 29.4 mol%, whereas strain Marseille-Q5883 has a genome of 1,997,945 bp with a 33.6 mol% G+C content. The genomic comparison of closely related species with strains Marseille-Q5893 and Marseille-Q5883 showed that all digital DNA–DNA hybridization (dDDH) and orthologous average nucleotide identity (OrthoANI) values were lower than the published species thresholds (70% and 95–96%, respectively). Based on these data, we conclude that strain Marseille-Q5893 belongs to a new species in the family Peptoniphilaceae and strain Marseille-Q5883 belongs to a new genus in the family Peptostreptococcaceae. For these two new bacterial species, the names Anaerococcus ihuae sp. nov. and Mediannikoviicoccus vaginalis gen. nov., sp. nov., were proposed.