Identification of Phyto-Fabricated Silver Nanoparticles as Antivirulence Agent against Pseudomonas aeruginosa

Pushpraj S. Gupta^1* Arnica F. Lal¹

• ¹Sam Higginbottom University of Agriculture, Technology and Sciences, India

Pseudomonas aeruginosa (P. aeruginosa) is the source of serious nosocomial infections, the most common of which is ventilator-associated pneumonia. The common gram-negative rod P. aeruginosa can grow on basic, inexpensive substrate culture media. P. aeruginosa infections continue to pose a substantial therapeutic problem. The QS (Quorum sensing) is a system that depends on information from the bacterial population that is transmitted by minuscule, diffusible molecules known as autoinducers, which are individually produced by each cell. The two main autoinducers of P. aeruginosa are acyl-homoserine lactone (AHL) and Pseudomonas quinolone signal (PQS), both of which are essential for the development and control of biofilm and pyocyanin. As a result of an increase in AHL content, the bacterium also makes more biofilm and pyocyanin. Anti-biofilm chemicals prevent the synthesis of the polymer matrix, limits cell adhesion and attachment, reduce the generation of virulence factors, and obstruct the quorum sensing system. Pyocyanin which is a phenazine derivative, is another virulence trait of P. aeruginosa QS signaling The present study focused on the antibiofilm and anti-pyocyanin production activity of Chrysin-fabricated silver nanoparticles (Nano-chrysin) against P. aeruginosa. In our study, Chrysin (Chy), which is a polyphenol, was fabricated with silver nanoparticles (AgNPs) to make Nano-chrysin. P. aeruginosa PAO1 strain was treated with Chrysin (50, 25, 12.5, and 6.25 µg/ml), silver nanoparticles (6.26, 3.13, 1.56, and 0.78 µg/ml) and formulated Nano-chrysin (3.13, 1.56, 0.78, and 0.39µg/ml) to find out the effectiveness of these compounds against biofilm and pyocyanin generation. Biofilm produced by P. aeruginosa PAO1 was found to be inhibited at sub-mic concentrations (3.13, 1.56, 0.78, and 0.39µg/ml) of Nano-chrysin and attenuation of pyocyanin production was in the range of submic concentrations (1.5, 0.75, 0.375 and 0.18µg/ml) which is more potent than Chy and AgNPs. The hemolytic and cytotoxicity data of Nano-chrysin also reveals dose-dependent destructions of erythrocytes and reduction in cell viability. The data confirmed that Nanochrysin is effective in inhibiting biofilm formation and pyocyanin production, produced by P. aeruginosa.