THE INHIBITORY ACTION OF SALIVA ON THE IN VITRO GROWTH OF BETA HEMOLYTIC STREPTOCOCCI

¹ Department of Microbiology and The Murry and Leonie Guggenheim Foundation, Institute for Dental Research, College of Dentistry, New York University, New York, N. Y.

Freshly stimulated saliva exhibits an inhibitory action toward the hemolytic streptococci under the stated in vitro experimental conditions. The factor is distinct from lysozyme, not filterable through the Seitz sterilizing filter; it may be associated with the oral microbial flora, and is effective in inhibiting growth of both stock and recent beta hemolytic streptococcal isolates. Since the factor inhibits the growth of hemolytic streptococci in the presence of laked blood, potato juice, or lyophilized catalase and is active under anaerobic conditions, we conclude it is distinct from hydrogen peroxide production in vitro.