Inhibition of Biofilm and Virulence Properties of Pathogenic Bacteria by Silver and Gold Nanoparticles Synthesized from Lactiplantibacillus sp. Strain C1

Abstract

The emergence of antibiotic resistance in microbial pathogens necessitates the development of alternative ways to combat the infections that arise. The current study used nanotechnology as an alternate technique to control virulence characteristics and biofilm development in Pseudomonas aeruginosa and Staphylococcus aureus. Furthermore, based on the acceptance and biocompatibility of the probiotic bacteria, we chose a lactic acid bacteria (LAB) for synthesizing two types of metallic nanoparticles (NPs) in this study. Using molecular techniques, the LAB strain C1 was isolated from Kimchi food samples and identified as Lactiplantibacillus sp. strain C1. The prepared supernatant from strain C1 was used to produce gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs). C1-AuNPs and C1-AgNPs were characterized physiochemically using a variety of instruments. C1-AuNPs and C1-AgNPs had spherical shapes and sizes of 100.54 ± 14.07 nm (AuNPs) and 129.51 ± 12.31 nm (AgNPs), respectively. C1-AuNPs and C1-AgNPs were discovered to have high zeta potentials of −23.29 ± 1.17 and −30.57 ± 0.29 mV, respectively. These nanoparticles have antibacterial properties against several bacterial pathogens. C1-AuNPs and C1-AgNPs significantly inhibited the initial stage biofilm formation and effectively eradicated established mature biofilms of P. aeruginosa and S. aureus. Furthermore, when P. aeruginosa was treated with sub-MIC levels of C1-AuNPs and C1-AgNPs, their different virulence features were significantly reduced. Both NPs greatly inhibited the hemolytic activity of S. aureus. The inhibition of P. aeruginosa and S. aureus biofilms and virulence features by C1-AuNPs and C1-AgNPs can be regarded as viable therapeutic strategies for preventing infections caused by these bacteria.

Silver nanoparticles synthesized from Pseudomonas aeruginosa pyoverdine: Antibiofilm and antivirulence agents

“…The AgNPs were synthesized with a modified version of the previous study of AgNP synthesis [ 27 ]. 2 mM of silver nitrate was dissolved in 10 mL of deionized water.…”

“…Several instruments were employed to characterize the PVD-AgNPs [ 27 ]. The morphological features of PVD-AgNPs were thoroughly investigated using field emission transmission electron microscopy (FETEM; JEM-F200, JEOL, Japan).…”

“…Pyocyanin and PVD production from P. aeruginosa in the presence of PVD-AgNPs was evaluated in the same manner as described earlier [ 27 ]. The pyocyanin production was carried out by first growing the cell culture (OD 600 = 0.05) for 24 h at 37 °C in the absence and presence of PVD-AgNPs (1–8 μg/mL).…”

“…The study involved the assessment of hemolytic activity by PVD-AgNPs towards S. aureus and P. aeruginosa as described earlier [ 27 ]. The cell culture of these bacteria (OD 600 = 0.05) was incubated with PVD-AgNPs (from 0.5 to 8 μg/mL) at 37 °C overnight.…”

“…Furthermore, NPs have a number of additional properties that make them a more viable approach to the management of microbial infections. These qualities include their tiny size, vast surface area, stability, biocompatibility, targeting to particular areas, and increased strength of cellular interactions [ 27 , 28 ].…”