NCIt definition : A non-taxonomic grouping of Streptococcal bacteria that are either alpha-hemolytic,
producing a green coloration on blood agar plates, or nonhemolytic. Within this heterogeneous
group, some species are commensal flora while others are human pathogens.;
Alternative definition : CDISC: Any bacterial organism that can be assigned to the species Streptococcus viridans.;