Effect of substrate surface hydrophobicity on the adherence of yeast and hyphal Candida

P>A biofilm composed of various microorganisms including Candida is found on denture surfaces and is likely to be involved in the etiology of denture-induced stomatitis. The purpose of this study was to examine the role of hydrophobic interactions in candidal adherence to acrylic surfaces, particularly that of the hyphal form of Candida albicans. Candida clinical isolates were used. Acrylic plates coated with carrageenan and hydrocolloid (Hitachi chemical, Tokyo, Japan) were used as a hydrophilic substratum. A microbial suspension was placed on each acrylic plate and incubated. All plates were washed in phosphate-buffered saline containing CaCl2 and MgCl2 [PBS (+)] and cells still adhering to the acrylic surface were collected by 0.25% trypsin treatment. Cell-surface hydrophobicity was estimated using a modification of the technique used to measure adherence to hydrocarbons. When the acrylic plates were coated with hydrophilic materials, the adherence of hydrophobic clinical isolates of Candida and the hydrophobic hyphal C. albicans decreased, whereas the adherence of non-hydrophobic Candida was not affected or increased. We suggest that hydrophilic coating of denture surfaces could be a potent method for reduction of the adherence of relatively hydrophobic fungal cells, particularly hyphal C. albicans, which causes denture stomatitis and related infections.