Variation in adhesion and cell surface hydrophobicity in Candida albicans white and opaque phenotypes

Abstract

A previous study had established that a select group of pathogenic isolates of Candida albicans was capable of switching heritably, reversibly and at a high frequency (10(-2) to 10(-3)) between two phenotypes ('white' or 'opaque') readily distinguishable by the size, shape, and color of colonies formed on agar at 25 degrees C. This paper describes experiments designed to determine the ability of these two phenotypes to attach to buccal epithelial cells (BECs) and plastic, and to compare the cell surface hydrophobicities of white and opaque phenotypes from three clinical isolates. 'White cells' were found to be significantly more adhesive to BECs, and a strong correlation was also found between phenotype adhesiveness and the percentage of BECs to which C. albicans had attached. The percentage of BECs with one or more attached C. albicans was approximately 90% for the white phenotype and approximately 50% for the opaque phenotype. 'Opaque cells', in contrast, were twice as hydrophobic as white cells, and the percentage of opaque cells bound to BECs by coadhesion was also double that of white cells. The differences in adhesion to plastic between the two phenotypes were not statistically significant and there was no distinct trend to suggest which phenotype might be more adhesive to plastic. These results indicate that several factors are involved in the adhesion of C. albicans to plastic, and confirm the hypothesis that cell surface hydrophobicity is of minor importance in direct adhesion to epithelial cells but that it may contribute to indirect attachment to epithelial cells by promoting yeast coadhesion.(ABSTRACT TRUNCATED AT 250 WORDS)