Biotypes of group A streptococci isolated from children.

Thirty-eight isolates of group A streptococci from patients with pharyngitis, 13 isolates from patients with pyoderma and 28 carrier strains were subjected to biotyping by carbohydrate fermentation tests and production of beta-glucuronidase. Biotype 10 was observed most frequently among clinical isolates and biotypes 3 and 4 were most common among carrier isolates.