Imidazole-induced morphological abnormalities of mitochondria of Candida albicans

The mitochondrial morphology of live Candida albicans samples treated with several imidazoles (miconazole, econazole and clotrimazole) was observed with a fluorescent carbocyanine probe, 3,3'-dihexyloxacarbocyanine [diO-C6-(3)], under a fluorescence microscope. Nearly all non-treated C. albicans cells carried only long tubular mitochondria. Treatment with antimycotics at half the minimum inhibitory concentrations (MIC100) rapidly induced mitochondrial cleavage or fragmentation, which was followed by recovery to the normal tubular morphology within 1 h. Exposing the yeast to drugs at concentrations higher than the MICs resulted in the development of swollen mitochondria or amorphous bodies. These phenomena were concentration dependent. The fluorescence images were also compared with ultrastructural images obtained by transmission electron microscopy.