Streptococcus cristatus isolated from a resected heart valve and blood cultures: case reports and application of phenotypic and genotypic techniques for identification.

BACKGROUND: Viridans streptococci are known as an important cause of endocarditis, but at present no cases of endocarditis caused by Streptococcus cristatus have been published, probably because phenotypic identification of viridans streptococci is tedious. Using tDNA-PCR, it is possible to identify to species level and to differentiate between species of the viridans group.