The effect of cetylpyridinium chloride (CPC) on the cell surface hydrophobicity and adherence of Candida albicans to human buccal epithelial cells in vitro

Purpose. This study examined the effects of cetylpyridinium chloride (CPC) on cell surface hydrophobicity (CSH) and adherence of blastospores of Candida albicans (MEN strain) to human buccal epithelial cells (BEC) in vitro. Methods. The effect of CPC treatment of either C. albicans blastospores or BEC on their subsequent adherence was determined using (SO4)-S-35 labelled blastospores in association with a Percoll(TM) gradient. The effects of CPC treatment of blastospores on their CSH was determined using Hydrophobic Interaction Chromatography. Results. Treatment of exponential and stationary phase blastospores with CPC (50 mu g mL(-1)) for 0.5-30 minutes, or with CPC (0.5-50 mu g mL(-1)) for 15 minutes resulted in significant reductions in both blastospore CSH and adherence to BEC in vitro. No correlation was apparent (r < 0.8) between reduced CSH and reduced blastospore adherence following treatment with CPC (0.5-50 mu g mL(-1)). Significantly reduced adherence of C. albicans (stationary or exponential growth phases) to human BEC was also observed following treatment of BEC with CPC (50 mu g mL(-1)) for 0.5-30 minutes or with CPC (0.5-50 mu g mL(-1)) for 15 minutes. Antiadherence effects were observed at both sub and super-minimum inhibitory concentrations of CPC. Conclusions. It is suggested that, whilst the ability of CPC to reduce the CSH of C. albicans may contribute to its reduced adherence to human BEC in vitro, reduced CSH is only one of several possible factors that contribute to the observed antiadherence effects.