A novel technique to evaluate the adhesion of Candida species to gingival epithelial cells

We developed an in vitro ATP assay technique to extract cellular and fungal ATP separately, which allowed to evaluate quantitatively the adhesion of the yeasts to monolayers of human gingival epithelial cells. Thirteen isolates of Candida spp. representing three species (i.e. Candida albicans, C. tropicalis and C. glabrata) were used in the present study. When the adherent capacity of the Candida species was compared, C. albicans exhibited highest capacity of adherence to gingival epithelial cells, followed by C. tropicalis, and C. glabrata was the lowest [analysis of variance (ANOVA), P < 0.01]. The germ tubes of C. albicans exhibited significantly higher adherence capacity than their blastoconidia cells (ANOVA, P < 0.01), which was not observed with a C. albicans isolate, defect of germ tube formation. Our results suggested that the adherence of C. albicans is promoted by germ tube formation and may play an important role in the pathogenesis of the fungus.