Evaluation of antimicrobial potential of synthesized gold and silver nanoparticles using aqueous extract of Mimusops coriacea

• Grant number: 19/13291-0
• Support type: Regular Research Grants
• Duration: November 01, 2019 - October 31, 2022
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal researcher: Marcia Regina Franzolin
• Grantee: Marcia Regina Franzolin
• Home Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Assoc. researchers: Lilia Coronato Courrol

Abstract

The alarming problem of multidrug resistance to antibiotics by pathogenic bacteria in recent decades has forced researchers to search for new molecules to get new drugs. Many bacteria, besides having their mechanisms of resistance, when they reach the stage of mature biofilm present a high degree of resistance against antimicrobial and the immune system of the host, being very important in its control. Naturally produced metal nanoparticles have shown satisfactory results against various bacteria and are nontoxic. This study aims to evaluate the antimicrobial and antibiofilm activity of silver and gold nanoparticles synthesized using aqueous extract obtained from leaves of Mimusops coriacea (Mc). Gram-positive and Gram-negative bacteria, both sensitive and multiresistant, and yeasts will be employed. The microbial suspensions will be treated with different concentrations of nanoparticles and synthesis conditions to verify antimicrobial activity through broth microdilution, to obtain the inhibition percentage compared to untreated isolates after verification of turbidity. If the Minimum Inhibitory Concentration (MIC) is obtained, the Minimum Bactericidal Concentration (MCB) will also be investigated. Colony Forming Units (CFU) will also be counted from treated and untreated wells. The violet crystal staining assay will be performed to verify the inhibition of biofilm formation after treatment, as well as viable microorganisms, will be quantified by counting Colony Forming Units. Confocal fluorescence microscopy will be used to evidence the inhibition of biofilm formation and preformed biofilm. The study of nanoparticles with antimicrobial activity would open a possibility for the search for new drugs that could be used in the treatment and prevention of microbial infections. (AU)