{
  "abstract": "Background: The Streptococcus anginosus group (SAG) (S. anginosus, S. intermedius, and S. constellatus) causes serious, potentially life-threatening, invasive infections, often in otherwise healthy individuals. However, the group's diversity is still poorly understood, and with it, the ability to identify prognostic markers of severe disease. Methods: Long-read sequencing produced closed genomes for 29 isolates from 25 patients hospitalised primarily for invasive SAG infections, and 21 isolates from 20 non-hospitalised controls. Genomes were classified with GTDB-Tk and combined with 211 reference genomes. After dereplication, 207 SAG genomes (38 isolate, 169 reference) representing 206 strains were analysed using: GTDB classification, average nucleotide identity, multi-marker and core-genome SNP phylogenies, recombination-aware analyses, mobilome, CAZyme and gapseq metabolic profiling, and lineage-aware genome-wide association testing for invasive phenotype. Results: Agreement between GTDB-Tk and MALDI-TOF taxonomic classifications was low (42.8%), including two S. massiliensis cases mis-identified by MALDI-TOF as SAG. S. anginosus resolved into four taxa (S. anginosus, S. hominis, S. whileyi and S. vaginalis). Phylogenies based on core genome single-nucleotide polymorphisms resolved these species into distinct clades, whereas 16S rRNA gene and multilocus sequence analysis phylogenies did not. The four ex-S. anginosus taxa showed a gradient of genomic cohesion, with S. vaginalis being near-clonal, in contrast to S. anginosus, which shared high levels of sequence ancestry with other neighbouring taxa. Carbohydrate utilisation was strongly lineage-associated, as was propensity for invasive disease. A ~15Kbp glycosaminoglycan utilisation locus was found in the three taxa of highest disease severity propensity (S. intermedius, S. constellatus, S. whileyi) which predicts a direct host glycosaminoglycan feeding mechanism that may contribute to invasive disease. No single functional feature, gene or core-genome SNP was associated with invasiveness however after lineage-adjustment. Combined feature analysis suggests S. vaginalis has undergone a niche restriction and has evolved for a primary existence in the female urogenital tract. Conclusions: Under-reported species may be mis-diagnosed as SAG invasive infections. SAG is more diverse than its current three-species definition, with the conventional S. anginosus species proposed to be classed into a complex of four distinct taxa. Invasive capacity appears to be an emergent system-level property rather than from individual features.",
  "abstract_shown": true,
  "affiliations": [
    "Australian Centre for Ecogenomics, University of Queensland, St Lucia, Queensland, Australia"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 9,
  "authors": [
    {
      "name": "A. Coleman"
    },
    {
      "name": "J. Liaw"
    },
    {
      "name": "D. Maresco-Pennisi"
    },
    {
      "name": "R. Deehan"
    },
    {
      "name": "P. N. A. Harris"
    },
    {
      "name": "A. Cervin"
    },
    {
      "name": "O. Edkins"
    },
    {
      "name": "J. Zaugg"
    },
    {
      "affs": [
        0
      ],
      "name": "S. Bialasiewicz"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/acfm7fbb20e7q.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.11.04.764143",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.11.04.764143v1.full",
  "id": "acfm7fbb20e7q",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.11.04.764143v1",
  "language": null,
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "microbiology"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.11.04.764143v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/acfm7fbb20e7q.ris",
  "sources": [
    {
      "first_seen": "2026-11-07T00:21:24Z",
      "native_id": "10.64898/2026.11.04.764143",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.11.04.764143v1"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "biorxiv:microbiology",
      "subfield": "microbiology"
    }
  ],
  "title": "Genomic analysis of the Streptococcus anginosus group; taxonomic implications, evolutionary insights and clinical considerations",
  "title_text": "Genomic analysis of the Streptococcus anginosus group; taxonomic implications, evolutionary insights and clinical considerations",
  "type": "preprint",
  "updated_at": "2026-11-08T00:21:09Z",
  "url": "https://research.draconitic.com/paper/acfm7fbb20e7q",
  "venue": "bioRxiv",
  "versions": []
}