Analysis of the molecular mechanisms of toxicity and tolerance of strains of Candida albicans, Candida glabrata and Streptococcus mutans to silver nanoparticles obtained by the 'green' synthesis: approach to scale of the genome

Abstract

Silver nanoparticles (AgNPs) have shown antimicrobial activity against several microorganisms, such as: Candida albicans, Candida glabrata, Streptococcus mutans and Staphylococcus aureus. Some toxic substances have been used in the synthesis of the AgNPs. 'Green' synthesis is a new approach for the synthesis of these nanoparticles, due to low toxicity. Extracts of Punica granatum L. (in special the peel) have been used in obtaining the AgNPs, due to high quantity of phenolic compounds (elagic acid, punicalagin) that are related to reduction of metallic ions. The mechanism of action subjacent to the antimicrobial effect of the AgNPs is not clearly defined. Thus, the aim of this study will be to contribute with the elucidation of the molecular mechanisms of toxicity of the AgNPs on Candida albicans, Candida glabrata and Streptococcus mutans. For this, nanoparticles will be synthesized by a 'green' method using extracts of the peel of a pomegranate (Punica granatum L.). The nanoparticles will be characterized by scanning electron microscopy (SEM). Analyses of SEM, transmission electron microscopy (TEM) and fluorescence will be performed in order to verify the interaction between the nanoparticles and the cells. The cellular response of the microorganisms to treatment with the AgNPs will be evaluate through of transcriptomics analysis using planktonic cells and formed biofilms.