RESUMO
The incidence of fungal infections has increased significantly over the past decades. Very often these infections are associated with biofilm formation on implanted biomaterials and/or host surfaces. This has important clinical implications, as fungal biofilms display properties that are dramatically different from planktonic (free-living) populations, including increased resistance to antifungal agents. Here we describe a rapid and highly reproducible 96-well microtiter-based method for the formation of fungal biofilms, which is easily adaptable for antifungal susceptibility testing. This model is based on the ability of metabolically active sessile cells to reduce a tetrazolium salt (2,3-bis(2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide) to water-soluble orange formazan compounds, the intensity of which can then be determined using a microtiter-plate reader. The entire procedure takes approximately 2 d to complete. This technique simplifies biofilm formation and quantification, making it more reliable and comparable among different laboratories, a necessary step toward the standardization of antifungal susceptibility testing of biofilms.
