Survey of the Yeast Population in Saliva and an Evaluation of Some Procedures for Identification of Candida albicans

Abstract

320 samples of saliva (stimulated and unstimulated) were collected from 160 apparently normal individuals between 20 and 30 years of age. One tenth milliliter aliquots of each saliva specimen were streaked on Littman''s medium containing bacitracin, 2 units per ml and chloromyce-tin, 20ug/ml. The plates were incubated at room temperature (20-25[degree]C) and observed at intervals of 2,5 and 14 days. An occasional strain belonging to the genus Pseudomonas was not inhibited. Of the salivary specimens 68% contained less than 200 "yeasts " and 55% less than 100 "yeasts" per ml saliva. In 73% of instances, one type of "yeast" colony was isolated. Twenty percent showed 2 types; 5% three types and the remainder 4 types. Among the 128(40.2%) salivary specimens from which "yeasts" were isolated, 97 (75.8%) could be classified as Candida species and approximately 60% were characterized as C. albicans on the basis of fermentation reactions, chlamydospore production, agglutination tests and the color reactions on Pagano-Levin medium. The superiorty of the corn meal agar and the cream of rice agar over other media for chlamydospore production is confirmed. The Pagano- Levin medium was a useful adjunct in confirming the presence of C. albicans. Although molds were isolated in approximately 9% of the specimens studied, it is the opinion of the authors that the isolates are primarily contaminants since morphologically similar isolates were obtained with little difficulty from the laboratory environment.