Inhibition of Quorum Sensing and Virulence Factors of Pseudomonas aeruginosa by Biologically Synthesized Gold and Selenium Nanoparticles

Abstract

The development of microbial resistance requires a novel approach to control microbial infection. This study implies the microbial synthesis of nanometals and assessment of their antivirulent activity against Pseudomonas aeruginosa. Streptomyces isolate S91 was isolated from soil with substantial ability for growth at high salts concentrations. The cell-free supernatant of S91was utilized for the synthesis of Au-NPs and Se-NPs. The 16S rRNA sequence analysis of Streptomyces S91 revealed that S91 had a high similarity (98.82%) to Streptomyces olivaceous. The biosynthesized Au-NPs and Se-NPs were characterized using a UV-Vis spectrophotometer, dynamic light scattering, transmission electron microscopy, energy dispersive X-ray diffraction and Fourier-transform infrared spectroscopy. The quorum sensing inhibitory (QSI) potential of Au-NPs and Se-NPs and the antivirulence activity was examined against P. aeruginosa. The QSI potential was confirmed using RT-PCR. The synthesized Au-NPs and Se-NPs were monodispersed spherical shapes with particle size of 12.2 and 67.98 nm, respectively. Au-NPs and Se-NPs eliminated QS in P. aeruginosa at a concentration range of 2.3–18.5 µg/mL for Au-NPs and 2.3–592 µg/mL for Se-NPs. In addition, Au-NPs and Se-NPs significantly inhibited QS-related virulence factors, such as pyocyanin, protease and, elastase in P. aeruginosa. At the molecular level, Au-NPs and Se-NPs significantly suppressed the relative expression of QS genes and toxins. Hence, the biosynthesized Au-NPS and Se-NPS could be substantial inhibitors of QS and virulence traits of P. aeruginosa.

Biosynthesis of Gold Nanoparticles and Its Effect against Pseudomonas aeruginosa

“…Lower concentrations, i.e., 100 and 50 µg/mL of TG-AuNPs, also caused reductions in the level of pyocyanin. Our results are in agreement with the previous studies, where 40-88% and 20-82% reductions were observed for the pyocyanin level at 1 /2 and 1 /4 MIC of gold nanoparticles [45].…”

“…Lower concentrations of 100 and 50 µg/mL also caused a reduction in biofilm, both in PAO1 and clinical isolates. Our results are also in agreement with the previous studies of Elshaer and shaaban [45], where they have shown the downregulation of biofilm formation by 26-68% and 21-37% at 1 /2 and 1 /4 MIC levels of gold nanoparticles. The loss of black consistency on the Congo red agar plate is the benchmark showing the decrease in EPS production.…”

Functional Materials to Overcome Bacterial Barriers and Models to Advance Their Development

“…In this context, silver and gold nanoparticles have been shown to display QSI activity against a range of bacterial species. [48,49] Their small size and high surface area-tovolume ratio make them effective at penetrating bacterial cells and disrupting QS signaling pathways. Also, lipid nanoparticles display promising potential as drug-delivery vehicles to combat bacterial biofilms.…”

Feathery Tellurium–Selenium Heterostructural Nanoadjuvant for the Synergistic Treatment of Bacterial Infections

“…However, the overuse of antibiotics has led to the development of severe bacterial resistance. Therefore, it has become necessary to find a solution to the challenge of developing novel therapeutic approaches that lessen or eliminate the usage of antibiotics . To address this hurdle, phototherapy has been found to offer feasibility for the treatment of bacterial infections due to its high bactericidal efficiency, delayed drug resistance, and ideal penetration .…”

“…Therefore, it has become necessary to find a solution to the challenge of developing novel therapeutic approaches that lessen or eliminate the usage of antibiotics. 2 To address this hurdle, phototherapy has been found to offer feasibility for the treatment of bacterial infections due to its high bactericidal efficiency, delayed drug resistance, and ideal penetration. 3 Encouragingly, various nanomaterials with both photothermal conversion ability and free-radical generation ability have been explored as potential nanoagents for phototherapy to enhance antibacterial efficacy.…”