Growth and acid production of Candida species in human saliva supplemented with glucose


Dr. L. P. Samaranayake, Microbiology Unit, Department of Oral Medicine and Pathology, Glasgow Dental Hospital and School, 378 Sauchiehall Street, Glasgow, G2 3JZ, Scotland.


Growth characteristics and acid production of oral isolates of Candida albicans and Candida glabrata in glucose supplemented and glucose-free, pooled, human whole saliva were examined. Both Candida species exhibited sigmoidal growth curves in hatch cultures of mixed saliva, supplemented with glucose. The growth of Candida in saliva was accompanied by a rapid decline in pH from 7.5 to 3.2 over 48 h and the major acidic components initiating and sustaining this pH drop were pyruvates and acetates. These acidic metabolites may play an important role in the pathogenesis of oral Candida infections.