Candida albicans switch phenotypes display differential levels of fitness

Candidiasis is a significant cause of morbidity and mortality in immunosuppressed individuals. Currently, there are limited treatment options for this opportunistic infection and there have been many reports in the literature of increased resistance to treatment. There is evidence to suggest that phenotypic switching of Candida albicans may play a role in this resistance. It was therefore, the purpose of this study to assess the variability among C. albicans switch phenotypes isolated from a single strain.

Four switch phenotypes from a single strain of Candida albicans isolated from an HIV+ individual were evaluated for growth rates, post-antifungal effects in the presence of fluconazole, fluconazole uptake and morphological changes after fluconazole exposure.

We found that, overall, smooth white and very wrinkled grew significantly faster then either ring or heavily myceliated and were most drastically affected by 4X and 6X MIC concentrations of fluconazole over a 24 hour period. When all four phenotypes were exposed to 64.

These results suggest that switch phenotypes from Candida albicans serve different roles in providing adaptability and survivability under differing conditions.