Fig. 1: Schematic of the study design and analysis workflow.

The S. mitis BSI isolates analysed were collected from clinically diagnosed IE cases, between 2001 and 2016, submitted to BSAC and UKHSA. The analysis involved WGS, population structure analysis, AMR genotyping and phenotyping, and identification of virulence genes using genotyping and bacterial genome-wide association analysis approaches to identify hypervirulent and dominant S. mitis lineages. The map of the UK and Ireland was generated by the authors in R software using the maps v4.0.0 package (https://cran.r-project.org/web/packages/maps/). The confirmed S. mitis isolates are described in Supplementary Data 1 and 2.