Spectrophotometric determination of the morphogenetic transformation by synchronous Candida albicans: effects of antifungal agents.

A spectrophotometric method for studying the morphogenetic transformation by Candida albicans is described. Synchronous yeast-phase C. albicans cells incubated at 35 degrees C formed germ-tubes and resulted in an absorbance increase at 340 nm but not at 595 nm. Furthermore, measurements of germ tube length increases correlated strongly (r2 > 0.95) with increases in absorbance at 340 nm during the morphogenetic transformation. Amphotericin B significantly affected the morphogenetic transformation, at the MIC and 1/10 MIC, whereby no increase in absorbance was observed at 340 nm. In contrast, identical measurements demonstrated that ketoconazole, at the MIC and 1/10 MIC, did not exhibit the same effects on the morphogenetic transformation by C. albicans cells.