A note on a code for the identification of the 'viridans' streptococci

A simple numerical code for the identification of 'viridans' streptococci was devised with Facklam's system of classification. This is based on biochemical criteria and consists of nine tests, with an additional five for the identification of closely related species and the subspecies or biotype of Streptococcus mutans. The 'viridans' streptococci can be divided into 10 species with the aid of this scheme while five subspecies and an additional biotype of Streptococcus mutans can be recognized. Advantages of this scheme are that the numerical code differentiates between isolates of the same species, distinguishes between biochemically active and non-active species and indicates similarities between species.