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

Abstract

A Gram-stain-negative or -positive, strictly anaerobic, non-spore-forming and pleomorphic bacterium (designated 14-104T) 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-C15 : 0 and C15 : 0 as the major fatty acids. The genome size of strain 14-104T 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 55929T. Reconstruction of phylogenetic and phylogenomic trees revealed that strain 14-104T and P. abscessus CCUG 55929T 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 14-104T represents a novel species in the genus Phocaeicola , for which the name Phocaeicola oris sp. nov. is proposed. The type strain is 14-104T (=BCRC 81305T= NBRC 115041T).