Influence of sub-inhibitory concentrations of systemic antifungal agents on adherence, filamentation and mitochondrial metabolism of Candida albicans

Objective. The effects of five systemic antifungals were compared: their ab ility to affect mitochondrial dehydrogenase activity of Candida albicans wa s examined with their ability to affect adherence and filamentation of this yeast. Materials and methods. Two adherence models were developed: adherence to bu ccal epithelial cells and to polystyrene. Results. Results showed that amphotericin B, used at subinhibitory concentr ation, inhibited all tested factors. However, the action of 5-fluorocytosin e, ketoconazole, itraconazole or terbinafine was more specific on one or a few tested factors, exhibiting either inhibition (ketoconazole, itraconazol e, terbinafine) or improvement (5-fluorocytosine, terbinafine). It was in p articular observed that a subinhibitory concentration of terbinafine did no t affect filamentation, but inhibited mitochondrial metabolism and adherenc e to polystyrene, and on the contrary, improved adherence to buccal epithel ial cells. Conclusion. Together these results highlighted the importance of the antifu ngal concentration which, below a certain threshold, could promote coloniza tion of the host tissues by C, albicans.