Penicillin-Resistant Streptococci from the Saliva

¹ Department of Pedodontics and Department of Microbiology, Dental School, Northwestern University, Chicago, Illinois

An investigation was performed to study the occurrence of penicillin-resistant streptococci in the saliva of 58 rheumatic patients treated with daily oral penicillin, as compared to 58 control patients not on penicillin therapy.

Forty-five of the 58 rheumatic patients (77.6 per cent) had penicillin-resistant isolates of streptococci, as compared to only seven of the 58 control patients (12.0 per cent).

The degree of penicillin-resistance of the streptococci in the control group was not as high as that of the rheumatic group. All 7 streptococcal isolates from the control group failed to grow in the presence of greater than 1 unit of penicillin. The rheumatic group had penicillin resistance to 10 units or more.

Streptococcus mitis and Str. salivarius were the most prevalent microorganisms recovered in the rheumatic group. There were 26 isolates of Str. mitis and 19 isolates of the inulin and noninulin fermenting Sir. salivarius.