THE ESTABLISHMENT OF A COMMUNITY OF ORAL BACTERIA THAT CONTROLS THE GROWTH OF CANDIDA-ALBICANS IN A CHEMOSTAT

The purpose of this study was to establish and identify a community of oral bacteria that controls the growth of Candida albicans in the che mostat. The chemostat was operated under glucose-limiting conditions a t a dilution rate of 0.05 h(-1) and inoculated with a yeast-free suspe nsion of a tongue scraping. After a steady state had been reached, it was inoculated with C. albicans to establish the yeast and determine w hether its growth could be contained. The steady-state community compr ised the species Streptococcus sanguis, Streptococcus sobrinus, Strept ococcus mitis, Lactobacillus casei, Eubacterium saburreum, Veillonella dispar and Fusobacterium nucleatum. Bacteroides gracilus and Haemophi lus segnis were also detected but infrequently. Yeast growth was suppr essed and yeast cells were lost at the same rate as the theoretical wa shout rate. It is concluded that this mixed community of oral bacteria can be used to identify the parameters that maintain the equilibrium between oral bacteria and C. albicans in the oral cavity.