Isolation and Description of sp. nov., a Novel Species, Isolated from a Stable Periodontitis Subject.

The genus currently counts a unique species, , isolated from periodontal pockets and associated with periodontitis and endodontic infections. This study contributed to the taxonomical and clinical knowledge of this genus by describing a novel species isolated from a saliva sample from a man in clinical gingival health following successful treatment of periodontitis. Morphological and chemotaxonomic characteristics were investigated using different growth conditions, pH, and temperature. Cellular fatty acid methyl ester (FAME) analysis was conducted by gas chromatography/mass spectrometry (GC/MS). Phylogenetic analysis based on 16S rRNA, orthologous average nucleotide identity (OrthoANI), and digital DNA-DNA hybridization (dDDH) relatedness were performed. Strain Marseille-Q4567 was found to be an anaerobic and non-spore-forming rod-shaped bacterium that grew at 28-41.5 °C (optimum 37 °C), pH 6.5-8.5 (optimum pH 7.5), and 5-10 g/L of NaCl (optimum 5 g/L). The predominant cellular fatty acid was C16:0 (64.2%), followed by unsaturated structures C18:1n9 (12.5%) and C18:2n6 (7.8%). Based on 16S rRNA sequence comparison, the closest phylogenetic neighbor was ATCC 51271 (98.23% similarity). The OrthoANI and dDDH values between strain Q4567 and ATCC 51271 were respectively 79.43% and 23.8%. Therefore, we concluded that strain Marseille-Q4567 represents a novel species of the genus , for which the name sp. nov. is proposed (= CSUR Q4567).