<p>Effect of Graphene Oxide and Silver Nanoparticles Hybrid Composite on P. aeruginosa Strains with Acquired Resistance Genes</p>

Abstract

Background: In the last decades, nosocomial infections caused by drug-resistant Pseudomonas aeruginosa became a common problem in healthcare facilities. Antibiotics are becoming less effective as new resistant strains appear. Therefore, the development of novel enhanced activity antibacterial agents becomes very significant. A combination of nanomaterials with different physical and chemical properties enables us to generate novel multi-functional derivatives. In this study, graphene oxide and polyvinylpyrrolidonestabilized silver nanoparticles hybrid nanocomposite (GO-Ag HN) were synthesized. The relation between antibiotic resistance and GO-Ag HN potential toxicity to clinical P. aeruginosa strains, their antibiotic resistance, and molecular mechanisms were assessed. Methods: Chemical state, particle size distribution, and morphology of synthesized GO-Ag NH were investigated using spectroscopy and microscopy techniques (UV-Vis, FTIR, XPS, TEM, SEM, AFM). Broad-spectrum antibiotic resistance of P. aeruginosa strains was determined using E-test. Antibiotic resistance genes were identified using polymerase chain reaction (PCR). Results: In this study, the toxicity of the GO-Ag NH to the isolated clinical P. aeruginosa strains has been investigated. A high antibiotic resistance level (92%) was found among P. aeruginosa strains. The most prevalent antibiotic resistance gene among tested strains was the AMPC betalactamase gene (65.6%). UV-vis, FTIR, and XPS studies confirmed the formation of the silver nanoparticles on the GO nanosheets. The functionalization process occurred through the interaction between Ag nanoparticles, GO, and polyvinylpyrrolidone used for nanoparticle stabilization. SEM analysis revealed that GO nanosheets undergo partial fragmentation during hybrid nanocomposite preparation, which remarkably increases the number of sharp edges and their mediated cutting effect. TEM analysis showed that GO-Ag HN spherical Ag nanoparticles mainly 9-12 nm in size were irregularly precipitated on the GO nanosheet surface. A higher density of Ag NPs was observed in the sheets' wrinkles, corrugations, and sharp edges. This hybrid nanocomposite poses enhanced antibacterial activity against carbapenem-resistant P. aeruginosa strains through a possible synergy between toxicity mechanisms of GO nanosheets and Ag nanoparticles. With incubation time increasing up to 10 minutes, the survival of P. aeruginosa decreased significantly. Conclusion: A graphene oxide and silver nanoparticles hybrid composite has been shown to be a promising material to control nosocomial infections caused by bacteria strains resistant to most antibiotics.

Synthesis and Characterization of Some Graphene Oxide Powders Used as Additives in Hydraulic Mortars

“…The peak at 1621 cm −1 can be assigned to the stretching vibrations of C=O [33], while the one at 1373 cm −1 can be due to the O-H bending vibration [34]. The peak at 1288 cm −1 corresponds to the -C-N bond (characteristic of PVP used in the synthesis of Ag nanoparticles) and the one at 1051 cm −1 can be due to the C-O-C stretching vibration of alkoxy group [35]. The peak noticed at 1718 cm −1 in the GO spectrum almost disappeared in the GO-Ag spectrum and the peak at 981 cm −1 decreased to 973 cm −1 , which indicates the interaction of the Ag nanoparticles with the functional groups that give absorption peak in those areas.…”

Enhanced Efficacy of Some Antibiotics in Presence of Silver Nanoparticles Against Multidrug Resistant Pseudomonas aeruginosa Recovered From Burn Wound Infections

“…Nanoparticle-antibiotic combinations have many benefits, such as reducing the dosage amount of both agents, which may minimize toxicity and increase the antimicrobial properties ( Buszewski et al, 2018 ). Therefore, such a combination may increase antibiotic concentrations at the place of antibiotic-microbe contact promoting increased affectivity ( Rai et al, 2012 ; Lozovskis et al, 2020 ). The nanoparticles of the certain metal display different unique properties compared to that of their large-size counterparts ( Gold et al, 2018 ).…”

“…Metal nanoparticles have been synthesized using a number of methods, including biological processes, chemical reduction of metal salts using reductive chemicals, sonochemical deposition, photochemical reduction, microwave irradiation, and laser irradiation ( Singh et al, 2015 ; Ali et al, 2017 ; Lozovskis et al, 2020 ). Biosynthesis of nanoparticles is an emerging highlight of the convergence of nanotechnology and biotechnology, which has gained rising attention due to the growing need to improve eco-friendly materials synthesis technologies ( Kalishwaralal et al, 2010 ; Deepak et al, 2011 ; Husseiny et al, 2015 ).…”

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

“…This is especially important for biofilm implant-associated infections if the only treatment option available is surgery combined with antibiotic therapy [81]. Silver nanoparticles (as a composite with graphene oxide) could be a promising material to control nosocomial infections caused by bacteria strains, which are resistant to antibiotics [82]. mPEGTH2-AgNPs have been demonstrated as a promising candidate to kill pathogenic microbes [68].…”