Gene expression profiling of the carbon pathways and virulence factors of Candida albicans in different carbon sources.

The metabolic flexibility of Candida albicans enables the fungus to colonise and survive diverse niches in the host, contributing to its the pathogenicity in human infections. The effects of different carbon sources available to the fungus, such as glucose, fructose, and galactose, were investigated through growth studies, gene expression profiling, and real-time quantitative PCR (qPCR). The expression of certain carbon assimilation and antifungal drug resistance genes of the fungus was studied. The growth of the C. albicans cells were significantly slowed when galactose was used as their carbon source compared to the cells grown in glucose. Fluconazole was also found to have a stronger antifungal effect towards the cells grown in glucose and fructose compared to those grown in galactose. From the gene expression profiling, it was found that C. albicans undergoes a massive metabolic reorganization when grown on fructose and galactose compared to when it is grown in glucose, leading to changes in the expression of various carbon metabolic genes such as ICL1 (0.86 in fructose, -5.67 in galactose), MLS1 (1.08 in fructose), and MDH1 (0.93 in fructose, -1.14 in galactose). With a deeper understanding on how diet affects a Candida infection and the efficacy of the antifungal treatments against it, better treatment strategies could be developed to complement current antifungal medication. The usage of lower doses of antifungal drugs or the development of complementary antifungal strategies would also ameliorate the situation about the rise of antifungal drug resistance among pathogenic fungi.