Population genomics of Streptococcus mitis in UK and Ireland bloodstream infection and infective endocarditis cases

• Published in: Nature communications Vol. 15; no. 1; pp. 7812 - 15
• Main Authors: Kalizang’oma, Akuzike, Richard, Damien, Kwambana-Adams, Brenda, Coelho, Juliana, Broughton, Karen, Pichon, Bruno, Hopkins, Katie L., Chalker, Victoria, Beleza, Sandra, Bentley, Stephen D., Chaguza, Chrispin, Heyderman, Robert S.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 06.09.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 45; 45/22; 45/23; 45/43; 631/326/22/1290; 631/326/325/2482; 631/326/41/2530; 692/699/255/1318; Adult; Aged; Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - therapeutic use; Antimicrobial agents; Antimicrobial resistance; Bacteremia - epidemiology; Bacteremia - microbiology; Bacteria; Drug Resistance, Bacterial - genetics; Endocarditis; Endocarditis - epidemiology; Endocarditis - microbiology; Endocarditis, Bacterial - epidemiology; Endocarditis, Bacterial - microbiology; Epidemiology; Female; Gene sequencing; Genetic analysis; Genetic diversity; Genetic Variation; Genome, Bacterial - genetics; Genomic analysis; Genomics; Humanities and Social Sciences; Humans; Ireland - epidemiology; Male; Middle Aged; multidisciplinary; Pathogenicity; Pathogens; Phylogeny; Science; Science (multidisciplinary); Streptococcal Infections - epidemiology; Streptococcal Infections - microbiology; Streptococcus infections; Streptococcus mitis; Streptococcus mitis - genetics; Streptococcus mitis - isolation & purification; United Kingdom - epidemiology; Virulence; Virulence - genetics; Virulence Factors - genetics; Whole Genome Sequencing; United Kingdom; Ireland; United Kingdom > UK
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-52120-z

Streptococcus mitis is a leading cause of infective endocarditis (IE). However, our understanding of the genomic epidemiology and pathogenicity of IE-associated S. mitis is hampered by low IE incidence. Here we use whole genome sequencing of 129 S. mitis bloodstream infection (BSI) isolates collected between 2001–2016 from clinically diagnosed IE cases in the UK to investigate genetic diversity, antimicrobial resistance, and pathogenicity. We show high genetic diversity of IE-associated S. mitis with virtually all isolates belonging to distinct lineages indicating no predominance of specific lineages. Additionally, we find a highly variable distribution of known pneumococcal virulence genes among the isolates, some of which are overrepresented in disease when compared to carriage strains. Our findings suggest that S. mitis in patients with clinically diagnosed IE is not primarily caused by specific hypervirulent or antimicrobial resistant lineages, highlighting the accidental pathogenic nature of S. mitis in patients with clinically diagnosed IE. In this genomic analysis, authors observe high genetic diversity among Streptococcus mitis isolates obtained from infective endocarditis cases over 16 years in the United Kingdom and Ireland.