Abstract

ERGOSTEROL BIOSYNTHESIS AND PATHOGENICITY MARKERS INHIBITION OF CANDIDA ALBICANS BY FUNGUS MEDIATED SILVER NANOPARTICLES.

Mohsin Maseet, Naureen Khan and Seemi Farhat Basir*

ABSTRACT

Candida albicans is an opportunistic fungus that causes mucosal and systemic infections with high mortality. Ergosterol is a useful fungal membrane component and an important target for antifungal drugs. In this study, biologically synthesized silver nanoparticles (AgNPs) have been evaluated for their effect on ergosterol biosynthesis and various pathogenicity markers of Candida albicans. Clinical and standard Candida albicans strains, in presence of their corresponding minimum inhibitory concentrations (MIC) of AgNPs, showed 75% and 45% reduction in ergosterol biosynthesis respectively. Growth curve studies of Candida albicans exhibited no growth at MIC and delayed exponential phase at MIC/2 of AgNPs for both the strains. Candida pathogenicity tools central for virulence, like hydrolytic enzymes (proteinase and phospholipase) secretion and transition from a yeast from to filamentous hyphae form, were also challenged with inhibitory and sub inhibitory concentrations of AgNPs. AgNPs reduced proteinase secretion by nearly 65% and 44% in standard and clinical strain of Candida albicans, respectively. Morphogenesis is an essential attribute of Candida albicans with direct implication for tissue invasion and virulence. MIC of AgNPs was found very effective in inhibiting yeast to hyphae transition. Hemolysis test, performed as a measure of toxicity of AgNPs demonstrated 4.8% and 11.68% lysis at MIC of standard and clinical strain of Candida albicans respectively. This indicates that silver nanoparticles have low cytotoxic activity on host cell. Biosynthesized AgNPs are seen to be very effective against pathogenicity markers and ergosterol biosynthesis inhibition in Candida albicans with low cytotoxic effect on host cell. On this account, biosynthesized AgNPs can be suggested as a promising antifungal agent.

Keywords: Candida albicans; Ergosterol; pathogenicity markers; AgNPs (silver nanoparticles); MIC (Minimum inhibitory concentration).