NON-HEMOLYTIC STREPTOCOCCI AND ACUTE RHEUMATIC FEVER.

1. Blood cultures from 25 cases of acute rheumatic fever were negative for non-hemolytic streptococci of both the alpha and gamma types. 2. Non-hemolytic (gamma type) streptococci were frequently recovered from the throats of patients with this disease. 3. Similar organisms were recovered just as frequently from the throats of normal individuals. 4. Although these non-hemolytic streptococci were morphologically and culturally identical, not only amongst themselves, but also when compared with stock Small and Birkhaug strains, all, including the latter, have failed to show any noteworthy degree of homogeneity. 5. Representative strains of these streptococci have proved to be relatively non-pathogenic for rabbits following intravenous injection. 6. These organisms, with a few exceptions, have failed to produce soluble skin-reacting toxins comparable to Birkhaug's standard test toxin. 7. The foregoing facts seem to invalidate the assumption that any of these non-hemolytic streptococci play a specific rôle in the etiology of acute rheumatic fever.