Molecular characterization of disease-associated streptococci of the mitis group that are optochin susceptible.

Eight optochin-susceptible (Opt(s)) alpha-hemolytic (viridans) streptococcus isolates were characterized at the molecular level. These isolates showed phenotypic characteristics typical of both viridans streptococci and Streptococcus pneumoniae. Comparison of the sequence of housekeeping genes from these isolates with those of S.