Streptococcus mitis is a viridans streptococcus and a normal commensal of the human
oropharynx. However, S. mitis can escape from this niche and cause a variety of infectious
complications including infective endocarditis, bacteraemia and septicaemia. It uses a
variety of strategies to effectively colonize the human oropharynx. These include expression
of adhesins, immunoglobulin A proteases and toxins, and modulation of the host immune
system. These various colonization factors allow S. mitis to compete for space and nutrients …