Effect of Biosynthesized Silver Nanoparticles on Bacterial Biofilm Changes in S. aureus and E. coli

Abstract

One approach for solving the problem of antibiotic resistance and bacterial persistence in biofilms is treatment with metals, including silver in the form of silver nanoparticles (AgNPs). Green synthesis is an environmentally friendly method to synthesize nanoparticles with a broad spectrum of unique properties that depend on the plant extracts used. AgNPs with antibacterial and antibiofilm effects were obtained using green synthesis from plant extracts of Lagerstroemia indica (AgNPs_LI), Alstonia scholaris (AgNPs_AS), and Aglaonema multifolium (AgNPs_AM). Nanoparticles were characterized by transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) analysis. The ability to quench free radicals and total phenolic content in solution were also evaluated. The antibacterial activity of AgNPs was studied by growth curves as well as using a diffusion test on agar medium plates to determine minimal inhibitory concentrations (MICs). The effect of AgNPs on bacterial biofilms was evaluated by crystal violet (CV) staining. Average minimum inhibitory concentrations of AgNPs_LI, AgNPs_AS, AgNPs_AM were 15 ± 5, 20 + 5, 20 + 5 μg/mL and 20 ± 5, 15 + 5, 15 + 5 μg/mL against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, respectively. The E. coli strain formed biofilms in the presence of AgNPs, a less dense biofilm than the S. aureus strain. The highest inhibitory and destructive effect on biofilms was exhibited by AgNPs prepared using an extract from L. indica.

Unravelling the Antimicrobial, Antibiofilm, Suppressing Fibronectin Binding Protein A (fnba) and cna Virulence Genes, Anti-Inflammatory and Antioxidant Potential of Biosynthesized Solanum lycopersicum Silver Nanoparticles

“…AgNPs had little impact on the biofilm that Gram-negative bacteria formed; their values ranged from 22 to 40.17 mm. Nonetheless, our biosynthesized silver nanoparticles were not as effective against the tested Gram-positive bacteria’s biofilm; 64.85 and 59.13% of the inhibitory effect on biofilm were found against Candida albicans and Candida sake , respectively; the maximum inhibitory effect was found against Candida species [ 71 ]. The high biofilm-suppression activity of silver nanoparticles was demonstrated against S. aureus , Bacillus subtilis , and Pseudomonas aeruginosa [ 72 ].…”

Role of Biofilm Formation in the Drop of Bacterial Resistance to Antibiotics after Animal Therapy with Silver Nanoparticles

“…18 The inhibitory effect of AgNPs on biofilm formation in vitro may depend on the size, concentration, and stability of the nanoparticles, as well as the specific bacterial species involved. 19,20 The present study is a continuation of our systematic study of a newly revealed phenomenon of the drop in antibiotic resistance caused by therapy with Argovit-C AgNP formulation. 19,21−24 In the previous works, we revealed that the reasons for the drop in antibiotic resistance after the animal therapy with Argovit-C AgNP formulation were caused by the decrease in antibiotic efflux by bacteria, 19,22−24 the drop of bacterial adhesion to the cells, and the diminishment in bacteria antilysozyme activity.…”

“…AgNPs can disrupt the integrity of bacterial cell membranes and interfere with cellular processes, making them effective at preventing biofilm formation and eradicating existing biofilms . The inhibitory effect of AgNPs on biofilm formation in vitro may depend on the size, concentration, and stability of the nanoparticles, as well as the specific bacterial species involved. , …”

Multi-functional copper oxide nanoparticles synthesized using Lagerstroemia indica leaf extracts and their applications

“…Thus, these diverse bioactive compounds make L. indica an ideal choice for nanoparticle synthesis. Several studies have examined the impact of biosynthesized silver nanoparticles on altering bacterial biofilms in both gram-negative and gram-positive bacteria [ 59 ], as well as investigating the anticancer, antimicrobial, and hemolytic properties of zinc oxide nanoparticles [ 60 ], using leaf extracts from L. indica . However, the potential of employing L. indica leaf extract in the synthesis of CuO NPs with multiple functionalities remains unexplored.…”