Genome-based identification of three strains of Capnocytophaga ochracea isolated from the oral cavities of Koreans

Abstract

Three strains (KCOM 2191, KCOM 2668, and KCOM 2812) of Capnocytophaga sp. isolated from a Korean population were initially classified by 16S rDNA sequence comparison. This study aimed to classify these strains at the species level using whole genome sequencing (WGS) analysis and determine their taxonomical characteristics. WGSs of the three strains were determined using PacBio RSII and/or Illumina platforms. Average nucleotide identity (ANI) and genome-to-genome distance calculator (GGDC) analyses were used to classify them at the species level. Cellular fatty acid (CFA) compositions of the three strains were determined using the MIDI/Hewlett Packard Microbial Identification System. The results of average nucleotide identity (ANI) analysis revealed that the KCOM 2191, KCOM 2668, and KCOM 2812 strains exhibited ANI values of 96.43%, 96.33%, and 96.33%, respectively, when compared with the type strain Capnocytophaga ochracea DSM 7271T. CFA profiling revealed predominance of iso-C15:0 (57.9%, 67.2%, and 64.9%, respectively), consistent with C. ochracea DSM 7271T (51.5%). Results indicate that KCOM 2191, KCOM 2668, and KCOM 2812 strains belong to C. ochracea. These strains could be used to study the pathogenesis of oral as well as systemic diseases dependent on C. ochracea.