Relationship between phospholipase expression and fluconazole resistance in Candida albicans

Abstract

Objective To explore the relationship between antifungal resistance and expression of a virulence factor phospholipase B1 in Candida albicans. Methods Total RNA was extracted from 15 fluconazole-resistant and 15 fluconazole-sensitive Candida albicans isolates. RT-PCR was performed to detect the expression of phospholipase B1 mRNA. Extracellular and intracellular proteins secreted by Candida albicans cells were concentrated using salting-out method and extracted by P0013B RIPA lysis buffer, respectively followed by Western-blotting analysis to detect the expression of extracellular and intracellular phospholipase B1 protein. Results The relative expression of phospholipase B1 mRNA was 0.6173 ± 0.1090 in fluconazoleresistant Candida albicans isolates, significantly higher than in fluconazole-sensitive isolates (0.2653 ± 0.0935,P ＜ 0.05). Increased expressions of extracellular and intracellular phospholipase B1 protein were noted in fluconazole-resistant Candida albicans isolates compared with fluconazole-sensitive isolates (0.4145 ± 0.2773 vs 0.2720 ± 0.2194, 0.1825 ± 0.1831 vs 0.2653 ± 0.0935, t = 2.703, 3.443, both P ＜ 0.05). Conclusions The expressions of phospholipase B1 mRNA and protein are elevated in fluconazole-resistant Candida albicans isolates, suggesting that the expression of phospholipase B1 may be associated with the occurrence of antifungal resistance in Candida albicans. Key words: Candida albicans; Phospholipase; Resistance; mRNA; Protein