INCIDENCE OF UREASE PRODUCING BACTERIA IN SALIVA'

The use of carbamide (synthetic urea) in a mouth rinse has been suggested be-cause in the mouth the carbamide is converted into ammonium carbonate which acts as an efficient buffer for acids. The combination of carbamide and quinine has been recommended as an antiseptic for oral use; the alkalinity resulting from the conversion of carbamide makes the quinine much more germicidal (2). Other therapeutic properties of carbamide such as ability to increase capillary proliferation, stimulate tissue granulations and dissolve necrotic tissue are prob-ably of minor importance in the use of carbamide as an oral rinse. Carbamide is converted into ammonium carbonate by heat or by the action of an enzyme called urease, which is found in saliva in minute quantities and also is produced by many species of proteolytic bacteria. No investigations of the urease-producing bacteria of the mouth could be found in the literature, so this study was undertaken to determine their incidence in the oral flora. Shulte and Thompson (3) studied the urea-splitting bacteria in urine and found potent urea-splitting organisms as part of the normal urethral flora in fifteen o