Effect of Silver Nanoparticles Against the Formation of Biofilm by Pseudomonas aeruginosa an In silico Approach

Abstract

Studies were undertaken to examine the mechanism of mediation of silver nanoparticles in inhibiting biofilm formation by Pseudomonas aeruginosa through LuxI/LuxR system of signal transduction. This study includes the basic signaling transduction mechanism LasR, QscR, RhlR, and Vfr signaling model systems. The arbitrary homology models built with the I-TASSER server were evaluated and validated with the Qmean web server. Based on the Z-score and the relative square mean distance (RMSD) values, the structures were validated. The interaction results of the nanoparticle with the rigid docking proved the requirement of minimal energy for the inhibition of the protein active site by the silver nanoparticle. This principle docking experiment suggests that the biofilm formation in Gram-negative bacteria can be inhibited by the silver nanoparticles at the signal transduction level. Graphical abstract Systematic outline of present study; Stage one provides the data sampling and generation of pdb systems to conform the structure of bacterial signal sytems like LasR/LasI; RhlR/RhrI; QscR/QscI; VfrR/VfrI. Stage two involves docking of silver nanoparticles with Bacterial signal protein strucutres which are listed in Stage one. The Final Stage involves in understanding the development of appropriate mechanism behind the biofilm inhibition by silver nanoparticles.

Biofilm inhibition and anti-quorum sensing activity of phytosynthesized silver nanoparticles against the nosocomial pathogen Pseudomonas aeruginosa

“…Docking of known QSI such as furanone C30 (de Nys et al 2006) with LasR was also performed and showed similar interactions as those with the natural ligand, 3-oxo-C 12 -HSL ( Figure 8b). Docking studies of AgNP (Figure 8c) show electrostatic interaction with the amino acid Asp73 in a LasR active site which is same as in previously reported data (Vyshnava et al 2016). Eugenol displayed hydrogen bond interactions with the hydroxyl group of Tyr56 and Tyr93, hydrophobic interactions with Trp60, Tyr64, Trp88 and Ala127 and electrostatic interaction with Asp73 in the LasR active site, with the docking score 3,290 (Figure 8d).…”

“…In addition, these nanoparticles exhibited considerable anti-biofilm activity against P. aeruginosa, signifying their role in decreasing bacterial resistance towards traditional antibiotics. Although there have been previous studies on the in silico analysis of eugenol and silver nanoparticles using P. aeruginosa QS regulator proteins (Rathinam et al 2017;Vyshnava et al 2016), to the best of the authors' knowledge, this is the first report which shows a stable interaction of eugenol-conjugated silver nanoparticle against P. aeruginosa with LasI and LasR/MvfR quorum sensing regulators.…”

Interactions of Gold and Silver Nanoparticles with Bacterial Biofilms: Molecular Interactions behind Inhibition and Resistance

“…Hence, proteins are one of the attractive targets for finding new antimicrobial therapies. To date, it has been shown that AuNPs and AgNPs, along with their respective ions, interact with several structural proteins, membrane proteins and several enzymes [ 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ]. In an experimental and molecular docking study, Shah et al evidenced the diverse action of AgNPs on various proteins of Pseudomonas aeruginosa [ 32 ].…”

“…Their overall experimental results gave proof of QS inhibition and biofilm destruction [ 32 ]. In a similar study, with homology modeling, Vyshnava et al showed interactions of four proteins involved in the signal transduction system of P. aeruginosa (LasR, QscR, RhlR and Vfr) with AgNPs, which resulted in their binding and inhibition [ 33 ]. In this study, it is reported that several amino acids—leucine, aspartate, arginine, lysine, tyrosine, arginine, alanine and tryptophan—from active sites of the four proteins interact with AgNPs [ 33 ].…”

“…In a similar study, with homology modeling, Vyshnava et al showed interactions of four proteins involved in the signal transduction system of P. aeruginosa (LasR, QscR, RhlR and Vfr) with AgNPs, which resulted in their binding and inhibition [ 33 ]. In this study, it is reported that several amino acids—leucine, aspartate, arginine, lysine, tyrosine, arginine, alanine and tryptophan—from active sites of the four proteins interact with AgNPs [ 33 ]. Structural proteins, such as bacterial amyloid FapC in P. aeruginosa , form a branched structure that helps in cell–cell adhesion, encasing dormant cells, QS, protection and biofilm integrity [ 34 ].…”