Silver Nanoparticles: Green Synthesis Using Brain Heart Infusion Culture Medium and Evaluation of Antimicrobial and Antibiofilm Activity against Acinetobacter baumannii

Abstract

Introduction: In recent years, the use of nanoparticles (NPs) to eliminate pathogenic bacteria is increasing. The development of biological and nontoxic methods for synthesizing NPs is an important topic in nanotechnology to allow the use of these NPs for health and medical purposes. This study aimed to synthesize silver NPs (AgNPs) using bacterial culture medium and then evaluated the antibacterial activity of these NPs against Acinetobacter baumannii. Materials and Methods: The synthesis of biocompatible AgNPs was performed by brain heart infusion culture medium. Synthesized NPs were observed using ultraviolet-visible spectroscopy and were characterized by Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were conducted to examine the morphology of AgNPs. The minimum inhibitory concentration (MIC) was determined to measure the antibacterial effect of AgNPs. Finally, antibiofilm activities of the synthesized AgNPs were assessed. Results: Ultraviolet-visible spectroscopy showed that the highest absorption of the synthesized NPs was at 420 nm. Results of SEM and TEM revealed that the morphology of particles was spherical and irregular, and their mean diameter was 26 nm. In addition, FTIR results confirmed that the reducing, capping, and stabilizing agents of NPs were proteins. Minimum inhibitory concentration of AgNPs ranged from 1.56 to 12.5 µg/ml, and at 2 MIC concentration, the biofilm formation inhibitory activity of NPS increased. Conclusion: Brain heart infusion medium was successfully applied for synthesizing stable AgNPs, and these NPs showed good antibacterial and antibiofilm activity against A. baumannii.