The survival of bacteraemic isolates of viridans streptococci, after the administration to subjects of prophylactic antibiotic cover, has been widely reported in the literature. This study demonstrated that the cause of bacteraemia was as a result of phenotypic tolerance amongst populations of bacteria, and both proposed a mechanism responsible for the appearance of this form of tolerance and the design of a model to evaluate candidate drugs for infective endocarditis (IE) prophylaxis
