Medical importance of biofilms in Candida infections.

Many Candida infections involve biofilm formation on implanted devices such as an indwelling catheter, a prosthetic heart valve or a denture. Candida biofilms can be formed in vitro using several model systems. In the simplest of these, organisms are grown on the surfaces of small discs of catheter material or denture acrylic. Biofilms of C. albicans prepared in this way consist of matrix-enclosed microcolonies containing yeasts, hyphae and pseudohyphae, arranged in a bilayer structure. Candida biofilms are resistant to a range of antifungal agents in current clinical use, including amphotericin B and fluconazole. Current research suggests that multiple mechanisms are involved in biofilm drug resistance.