Conditions for optimal Candida biofilm development in microtiter plates.

Development of Candida spp. biofilms on medical devices such as catheters and voice prosthesis has been recognized as an increasing clinical problem. Simple device removal is often impossible, while in addition, resulting candidal infections are difficult to resolve due to their increased resistance to many antifungal agents. Susceptibility studies of clinical isolates are generally performed according to the CLSI standard, which measures planktonic cell susceptibility, but similar standards have not been designed or applied to testing of cells growing within a biofilm. As consistent biofilms from many strains are more difficult to simultaneously obtain and analyze than are independent planktonic cultures, any standard assay must address these concerns. In the present chapter, optimized conditions that promote biofilm formation within individual wells of microtiter plates are described. In addition, the method has proven useful in preparing C. albicans biofilms for investigation by a variety of microscopic and molecular techniques.