Complete genome sequence of Streptococcus sp. strain KHUD₀13 isolated from the human buccal mucosa

OBJECTIVE: The genus Streptococcus constitutes a major component of the human oral microbiome and exhibits substantial genomic diversity at the species level. However, complete and high-quality reference genomes remain limited for many closely related oral streptococci, constraining accurate comparative and taxonomic analyses. The objective of this Data Note was to generate and report a complete genome sequence of Streptococcus sp. strain KHUD₀13, isolated from the human buccal mucosa, and to provide a genomic context for comparison with closely related species. DATA DESCRIPTION: Long-read sequencing using the PacBio Revio platform generated 89, 500 high-fidelity (HiFi) reads with a mean read length of 6, 960 bp. Genome assembly produced a single circular chromosome of 1, 988, 919 bp with a G + C content of 42. 5%. Genome annotation identified 1, 827 protein-coding genes, four ribosomal RNA operons (5 S, 16 S, and 23 S), and 62 transfer RNA genes, with an estimated completeness of 98. 8%. Average Nucleotide Identity (ANI) analysis indicated that strain KHUD₀13 is most closely related to the Streptococcus ilei type strain (GCA₀00479335. 1), with a value of 94. 39% and an alignment coverage of 86. 55%, consistent with genomic divergence at the species boundary. Comparative genomic analysis with four publicly available S. ilei genomes identified 179 gene clusters unique to KHUD₀13, predominantly associated with replication, recombination, and repair, as well as cell wall and membrane biogenesis and transcription. This genome sequence provides a valuable resource for strain-level comparative and taxonomic studies of oral streptococci.