Influence of aeration of Candida albicans during culturing on their surface aggregation in the presence of adhering Streptococcus gordonii

Candida albicans surfaces are extremely sensitive to changes in growth cond itions. In this study, adhesion to glass of aerated and non-aerated C. albi cans ATCC 10261 in the presence and absence of adhering Streptococcus gordo nii NCTC 7869 was determined in a parallel plate flow chamber. In addition, the influence of aeration on the yeast cell surface hydrophobicity, surfac e charge, and elemental cell surface composition was measured. S. gordonii adhering at the glass surface caused a reduction in the initial deposition rate of C. albicans, regardless of aeration. In a stationary end-point, onl y adhesion of nonaerated C. albicans was suppressed by the adhering S. gord onii. Non-aerated yeasts had a higher O/C elemental surface concentration r atio, indicative of cell surface polysaccharides, than aerated yeasts, at t he expense of nitrogen-rich cell surface proteins. Both yeasts were essenti ally uncharged, but the nitrogen-rich cell surface of aerated yeasts had a slightly higher water contact angle than non-aerated yeasts. Summarizing, t his study suggests that highly localized, hydrophobic cell surface proteins on C. albicans are a prerequisite for their interaction with adhering stre ptococci. (C) 1999 Federation of European Microbiological Societies. Publis hed by Elsevier Science B.V. All rights reserved.