Novel Multilocus Sequence Typing and Global Sequence Clustering Schemes for Characterizing the Population Diversity of Streptococcus mitis

Abstract

Streptococcus mitis is a common oral commensal and an opportunistic pathogen that causes bacteremia and infective endocarditis; however, the species has received little attention compared to other pathogenic streptococcal species. Effective and easy-to-use molecular typing tools are essential for understanding bacterial population diversity and biology, but schemes specific for S. mitis are not currently available.

Population genomics of an accidental pathogen Streptococcus mitis from patients with bloodstream infection and infective endocarditis in the UK and Ireland

“…Population genetic diversity of IE-associated S. mitis S. mitis strains are known to be highly diverse 16,25,32,[35][36][37][38] , but accurately assessing S. mitis population structure has been a challenge due to limited S. mitis genome sequences and species speci c molecular genotyping tools. Because of this, it remains unclear whether speci c lineages predominantly cause BSIs associated with S. mitis in localised populations and over time.…”

“…The plot shows that the UK IE S. mitis belonged to unique GSCs, however, two isolates isolated in 2014 and 2016 belonged to GSC27, and another two isolates collected in 2007 and 2015 were assigned to lineage GSC28. Multiple carriage isolates belonging to the same GSC were largely from a previous study that sampled multiple isolates from individuals 32 . GSC1 had the highest frequency of 23 isolates and was also likely due to sampling from the same individual.…”