A Serum Depressor of the Human Salivary Antilactobacillus Factor

¹ School of Dentistry, University of Washington, Seattle, Washington

A substance which depresses the salivary antilactobacillus system was demonstrated in some mammalian sera. Sera from the rabbit and human produced the greatest depression of the antilactobacillus activity of saliva, whereas guinea pig, sheep, and rat sera showed a lesser effect. Thiocyanate, the lactobacillus bactericidin cofactor, neither formed a non-dialyzable complex with the depressor nor was inactivated by it. The non-dialyzable component of the antilactobacillus system was not irreversibly inactivated by the serum depressor when pre-incubated with it for 24 hours. The serum depressor was non-dialyzable and was absorbed on Bentonite.