Influence of growth conditions on Candida albicans adhesion, hydrophobicity and cell wall ultrastructure

The effect of cultivation in 13 media (10 complex, and three synthetic), as well as altering growth conditions, on Candida albicans adhesion, cell surface hydrophobicity and cell wall ultrastructure was studied. Adhesion of C. albicans to buccal epithelial cells (BECs) was significantly modified by all of the factors tested, particularly growth medium. In general, optimal adhesive activity for C. albicans was observed when the cells were grown in defined media (depending on the carbohydrate used) and/or at 25 degrees C. Moreover, significant differences in adhesion to BECs were noted when C. albicans was grown in the same complex medium from different manufacturers and in different batches of medium from the same manufacturer. Electron microscopy revealed significant differences in surface topography and cell wall ultrastructure of C. albicans grown in different media but none of these differences, including presence or absence of an outer floccular layer, appeared to correlate with the adhesive changes noted, which raises questions regarding the location and nature of the Candida adhesin(s). Likewise, cell surface hydrophobicity could not be correlated with adhesion to BECs but may have influenced yeast coadhesion. The results indicate that Candida adhesion is highly dependent upon the cultivation conditions of the yeast cells tested, and may explain discrepancies in the literature regarding the biochemical nature of the surface component(s) responsible for C. albicans adhesion.