Candida albicans biofilm drug resistance: role of CDR1 gene

Abstract number: P1366

Agarwal V., Pruthi P., Pereira B., Pruthi V.

Objective:Candida albicans is prominent human fungal pathogen which is known to cause infections mainly in its biofilm mode of growth. Since years, azole drugs and its derivatives continue to dominate as antifungal agents against Candida related infections. Even though very widely acclaimed for their efficacy, these drugs are known to have side effects and limited action due chemical reaction into biofilm matrix and over expression of drug efflux pumps. In this work, we report that CDR1 gene of C. albicans is responsible for enhanced drug resistance in biofilm mode of growth.

Methods: The S. cerevisiae strain used was AD1-8u- as cloning host and Apcdr1 was its derivative expressing Candida drug resistance protein (Cdr1p). Fluconazole commonly used against Candida infections was chosen as a positive control. Biofilm quantification was done by XTT (2,3-bis[2-Methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) reduction assay.

Results: Characterisation of the clone Apcdr1 showed expression of CDR1 gene inside S. cerevisiae host AD1–8u-. Data showed that Apcdr1 was about 48 times resistant than AD1-8u- for fluconazole, while in biofilm mode of growth this resistance was increased to 73 times for the same drug.

Conclusions: It is encouraging to note that CDR1 gene is responsible for C. albicans biofilm associated drug resistance and overexpressed during biofilm formation.