Effect of antifungal agents on the adherence of Candida albicans to murine gastrointestinal mucosal surfaces

Abstract

The in-vitro adherence of Candida albicans to murine gastrointestinal mucosal surfaces was investigated in the presence of sub-inhibitory concentrations of amphotericin B, ketoconazole and itraconazole. Each antifungal drug showed a significant ability to reduce the adherence of C. albicans to gastric and jejunal mucosa. However, the outcome of an adherence assay was dependent on pH, drug concentration and C. albicans strain. The type of mucosal surface and its cellular arrangement also had an important role to play. Sub-inhibitory concentrations of amphotericin B, ketoconazole and itraconazole significantly reduced the adherence of an azole sensitive strain C. albicans 3436. These effects were influenced by the type of mucosal surface and the concentration of the antifungal drug. Sub-inhibitory concentrations of amphotericin B inhibited the adherence of an azole resistant strain. C. albicans 3310, to stomach and jejunal mucosal surfaces while sub-inhibitory concentrations of ketoconazole only significantly reduced this strain's adherence to gastric mucosal explants. Sub-inhibitory concentrations of itraconazole had little effect. Amphotericin B reduced the adherence of C. albicans 3436 to gastric mucosal explants when assays were performed at physiological pH levels, an effect dependent on concentration. This drug also reduced the adherence of strain 3436 to jejunal mucosal cells and explants at physiological pH levels, though results obtained from assays involving jejunal mucosal explants, incubated at pH 8.0, were concentration dependent.