THE CLASSIFICATION OF NONHEMOLYTIC STREPTOCOCCI RECOVERED FROM BACTEREMIA OF DENTAL ORIGIN

¹ Tufts College Dental School, Boston, Mass.

One hundred sixty strains of aerobic nonhemolytic streptococci, isolated from the blood of patients after dental extractions, were classified by serologic and physiologic tests. Forty-seven strains were members of Lancefield Groups A, C, F, K, and L. Of the remaining strains, 94 were identified as viridans and 19 could not be classified.

There is little doubt that all of the species recovered occur in the oral cavity. The present knowledge of their proportional distribution in the mouth is too scanty to attempt a comparison with their representation in blood cultures. Although Streptococcus saltivarius is one of the more common members of the oral flora, we found only a small number in our collection. Streptococcus sanguis has been isolated from a high percentage of cases of subacute bacterial endocarditis, yet we have identified few in our bacteremia studies. On the strength of the data available we may conclude that a few of the streptococci recovered from bacteremia of dental origin are potential producers of subacute bacterial endocarditis.

Streptococcemia was frequently caused by 2 or more different strains of organisms. When streptococci were recovered repeatedly from blood samples of the same patient, the strains were rarely identical. The species of streptococci recovered did not show any relationship to the medical history of the patient.