Fucoidan-Stabilized Gold Nanoparticle-Mediated Biofilm Inhibition, Attenuation of Virulence and Motility Properties in Pseudomonas aeruginosa PAO1

Abstract

The emergence of antibiotic resistance in Pseudomonas aeruginosa due to biofilm formation has transformed this opportunistic pathogen into a life-threatening one. Biosynthesized nanoparticles are increasingly being recognized as an effective anti-biofilm strategy to counter P. aeruginosa biofilms. In the present study, gold nanoparticles (AuNPs) were biologically synthesized and stabilized using fucoidan, which is an active compound sourced from brown seaweed. Biosynthesized fucoidan-stabilized AuNPs (F-AuNPs) were subjected to characterization using UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), field emission transmission electron microscopy (FE-TEM), dynamic light scattering (DLS), and energy dispersive X-ray diffraction (EDX). The biosynthesized F-AuNPs were then evaluated for their inhibitory effects on P. aeruginosa bacterial growth, biofilm formation, virulence factor production, and bacterial motility. Overall, the activities of F-AuNPs towards P. aeruginosa were varied depending on their concentration. At minimum inhibitory concentration (MIC) (512 µg/mL) and at concentrations above MIC, F-AuNPs exerted antibacterial activity. In contrast, the sub-inhibitory concentration (sub-MIC) levels of F-AuNPs inhibited biofilm formation without affecting bacterial growth, and eradicated matured biofilm. The minimum biofilm inhibition concentration (MBIC) and minimum biofilm eradication concentration (MBEC) were identified as 128 µg/mL. Furthermore, sub-MICs of F-AuNPs also attenuated the production of several important virulence factors and impaired bacterial swarming, swimming, and twitching motilities. Findings from the present study provide important insights into the potential of F-AuNPs as an effective new drug for controlling P. aeruginosa-biofilm-related infections.

Biogenic Gold Nanoparticles as Potent Antibacterial and Antibiofilm Nano-Antibiotics against Pseudomonas aeruginosa

“…They showed the decrease in the biofilm-forming ability of PAO1 using Baicalin-conjugated nanoparticles. Our findings of biofilm inhibition using crystal violet assay agreed with those of Khan et al [44]. They showed that fucoidan-stabilized AuNPs inhibited biofilm formation.…”

Antimicrobial and Antibiofilm Capacity of Chitosan Nanoparticles against Wild Type Strain of Pseudomonas sp. Isolated from Milk of Cows Diagnosed with Bovine Mastitis

“…The antibiofilm efficacy of NQo at sub-MICs was quantified by using crystal violet method [ 25 ]. For this assay, 2 strategies were used.…”

“…Qo displays unique properties such as biodegradability and biocompatibility proving to be a simple and cost-effective alternative with many applications such as food safety and biomedicine [ 23 , 24 ]. Qo is known to have antibacterial and antibiofilm properties in Gram-positive bacteria such as Staphylococcus aureus and Gram-negative like Escherichia coli and Salmonella typhimurium [ 25 , 26 , 27 ].…”

Bactericidal Activity of Usnic Acid-Chitosan Nanoparticles against Persister Cells of Biofilm-Forming Pathogenic Bacteria

“…The detailed characterization of the newly prepared UA-CS NPs was carried out using different instrumentations and the procedures as described earlier [82,83]. The UV-visible-absorption spectroscopy was carried out by scanning over wavelength ranging from 200 to 800 nm using a microtiter plate reader (BioTek, Winooski, VT, USA).…”

“…The bactericidal properties of UA-CS NPs were determined by microbroth dilution method as described earlier [82]. Briefly, the seed culture of each strain obtained from growing overnight in their respective growth media was being diluted in fresh culture media.…”