Adherence of Candida albicans to epithelial cells: studies using fluorescently labelled yeasts and flow cytometry

摘要: Summary: Candida albicans adherence to epithelial cells is the first step in infectious process, but spite of its importance, current methods for quantitative measurement C. vitro have some serious limitations. They are based on filtration assays and either microscopic or radiometric analysis. The reaction usually carried out with a large excess yeasts (100-fold) over order perform analysis, which slow, subjective limited 100-200 thus lacks statistical power. analysis fails measure individual cells. A method measuring yeast that overcomes these problems has been developed. It labelling fluorogenic marker 2′,7′-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein acetoxymethyl ester (BCECF) prior reaction, analysing 104 by flow cytometry, while nonbound excluded gating. Two subpopulations buccal (BECs) differ their mean fluorescence intensities per cell (MFIs) were observed: one MFI did not exceed nonspecific fluorescence, other as high higher than labelled yeasts. two represent yeast-free yeast-binding cells, respectively, increment BECs extent adherence. Control experiments confirming previously described basic features adherence, such enhanced at increasing excess, diminished trypsin-treated heat-inactivated yeasts, differential various species, supported validity assay. possibility studying reliably low yeast: ratios, better mimic adhesion it occurs vivo, an important advantage New findings, using this method, included observation exfoliated from diabetic patients exhibited same capacity healthy controls, early human ontogenic stages had significantly lower level those later stages.