Silver nanoparticle and plant molecule combinations synergistically inhibit drug resistant biofilms in candida albicans

Abstract

Anti-biofilm activity of silver nanoparticles (SNPs) in combination with four molecules i.e., Geraniol, β-Ionone, Citral and Carvacrol were analysed in a polystyrene microplate based in vitro biofilm model using XTT-metabolic assay. SNPs dosages required for the inhibition of anti-biofilm activity were reduced by the addition of the above molecules. MIC of SNPs against planktonic growth of C. albicans ATCC 90028 was reduced by eight fold in presence of geraniol. This interaction was also synergistic in case of C. albicans clinical isolate GMC 03. Geraniol-SNPs combination was synergistic against developing biofilms in both the strains and reduced the MIC of SNPs by 16 fold in C. albicans ATCC 90028. Eight fold decrease in MIC was observed in presence of 500 μg/ml of β-ionone in C. albicans ATCC 90028. MIC of SNPs against mature biofilm forms were brought down by sixteen fold by geraniol. Combination of SNPs-β-ionone caused eight fold decrease in the MIC of SNPs against mature biofilm forms in C. albicans ATCC 90028.