Phocaeicola oris sp. nov., an anaerobic bacterium isolated from the saliva of a patient with oral squamous cell carcinoma

A Gram-stain-negative or-positive, strictly anaerobic, non-spore-forming and pleomorphic bacterium (designated 14-104^T) was isolated from the saliva sample of a patient with oral squamous cell carcinoma. It was an acid-tolerant neutralophilic mesophile, growing at between 20 and 40 °C (with optimum growth at 30 °C) and pH between pH 3.0 and 7.0 (with optimum growth at pH 6.0–7.0). It contained anteiso-C_15:0 and C_15:0 as the major fatty acids. The genome size of strain 14-104^T was 2.98 Mbp, and the G+C content was 39.6 mol%. It shared <87% 16S rRNA sequence similarity, <71% orthologous average nucleotide identity, <76% average amino acid identity and <68%% of conserved proteins with its closest relative, Phocaeicola abscessus CCUG 55929^T. Reconstruction of phylogenetic and phylogenomic trees revealed that strain 14-104^T and P. abscessus CCUG 55929^T were clustered as a distinct clade without any other terminal node. The phylogenetic and phylogenomic analyses along with physiological and chemotaxonomic data indicated that strain 14-104^T represents a novel species in the genus Phocaeicola, for which the name Phocaeicola oris sp. nov. is proposed. The type strain is 14-104^T (=BCRC 81305^T= NBRC 115041^T).