Oral adhesion of yeasts.

Oral adhesion of yeasts probably occurs by interaction between yeast cell adhesins and oral epithelial cell receptors. In Candida albicans mannoprotein, glucan, chitin, cell wall proteins, and lipids are possible adhesins. Mannoprotein appears as a fibrillar or floccular outermost layer in stationary-phase cells grown in sugar-rich medium. Preincubation of buccal epithelial cells (BECs) with concanavalin A inhibits adhesion, as does suppression of mannoprotein production by tunicamycin. Germ tubes adhere more easily to BECs and plastic than do blastospores. Methyl-alpha-D-mannoside may be analogous to the yeast adhesin or epithelial cell receptor because it inhibits adhesion of C. albicans to BECs. L-Fucose, N-acetyl-D-glucosamine, or D-mannose, having the same effect, may also function as epithelial cell receptors. Other factors affecting yeast adhesion may be fibronectin, hydrophobicity, s-IgA, and indigenous bacteria. Growth of yeasts to stationary phase in sugar-rich media promotes adhesion to acrylic, as do divalent cations and serum. Saliva, chlorhexidine, and Streptococcus salivarius inhibit adhesion of yeasts.