Biofilm Eradication Using Biogenic Silver Nanoparticles

Abstract

Microorganisms offer an alternative green and scalable technology for the synthesis of value added products. Fungi secrete high quantities of bioactive substances, which play dual-functional roles as both reducing and stabilizing agents in the synthesis of colloidal metal nanoparticles such as silver nanoparticles, which display potent antimicrobial properties that can be harnessed for a number of industrial applications. The aim of this work was the production of silver nanoparticles using the extracellular cell free extracts of Phanerochaete chrysosporium, and to evaluate their activity as antimicrobial and antibiofilm agents. The 45–nm diameter silver nanoparticles synthesized using this methodology possessed a high negative surface charge close to −30 mV and showed colloidal stability from pH 3–9 and under conditions of high ionic strength ([NaCl] = 10–500 mM). A combination of environmental SEM, TEM, and confocal Raman microscopy was used to study the nanoparticle-E. coli interactions to gain a first insight into their antimicrobial mechanisms. Raman data demonstrate a significant decrease in the fatty acid content of E. coli cells, which suggests a loss of the cell membrane integrity after exposure to the PchNPs, which is also commensurate with ESEM and TEM images. Additionally, these biogenic PchNPs displayed biofilm disruption activity for the eradication of E. coli and C. albicans biofilms.

Biogenic Silver Nanoparticles as a Strategy in the Fight Against Multi-Resistant Salmonella enterica Isolated From Dairy Calves

“…The surface functional groups, capping of the silver nanoparticles, were characterized by Confocal Raman Microscopy. As previously reported, the presence of the band positioned at 230 cm –1 and Raman bands positioned at the fingerprint region can be attributed to the Ag-N stretching mode and to the presence of amino acids, respectively, suggesting that proteins from the fungal extract are part of the capping ( Estevez et al, 2020 ).…”

Optomechanical Processing of Silver Colloids: New Generation of Nanoparticle–Polymer Composites with Bactericidal Effect

“…The fact that the tested samples exhibited almost no antibacterial effects corresponds with the general stability of the AgNP attachment to polymer support and low formation ability of Ag ions, which are released into the surrounding media (see Table 2 ). These properties may implicate potential uses of developed materials in clinical practice [ 43 , 44 , 45 ], where the stability of the AgNP/polymer interface may be advantageous in prevention of biofilm formation [ 46 , 47 ] with long-term stability. Therefore, our further experiments address the ability of newly developed surfaces to prevent and inhibit biofilm formation.…”

Green Silver and Gold Nanoparticles: Biological Synthesis Approaches and Potentials for Biomedical Applications

“…Another rather valuable property of AgNPs is their biofilm-eradicating capability [ 218 , 219 ]. Biofilm formation is a very important virulence factor of several pathogenic bacteria and yeasts.…”

“…This matrix prevents the penetration of the conventional antibiotics; therefore, matrix-embedded cells are resistant to the antibiotic treatment and can be the sources of chronic or recurrent infections. However, AgNPs are capable of diffusing in the matrix and kill the cells in the inner layer of the biofilm [ 218 ]; thus, such a biofilm-inhibiting effect of silver nanoparticles is a paramount feature that should be emphasized more, especially in preventive antimicrobial application settings. The absorption and penetration of silver nanoparticles across the biofilm matrix depends on their size as well as on the surface materials, which in case of green synthesized nanoparticles can be quite complex; therefore, during biological synthesis, the appropriate approach and capping agent has to be chosen with care.…”