S. sanguinis may gain entrance to the bloodstream when opportunity presents (dental cleanings and surgeries) and colonize the heart valves, particularly the mitral and aortic valves, where it is the most common cause of subacute bacterial endocarditis.

Once an infection has occurred, treatment is much more complicated and generally involves the administration of several weeks of penicillin and aminoglycoside antibiotics.

[citation needed] The complete genomic sequence of S. sanguinis was determined in 2007 by laboratories at Virginia Commonwealth University.

[3] Natural genetic transformation is a sexual process involving DNA transfer from one bacterial cell to another through the intervening medium, and the integration of the donor sequence into the recipient genome by homologous recombination.

[4] An essential genes database (ePath) for >4000 bacterial species is developed based on this finding.