Biofabrication of Gold Nanoparticles Using Capsicum annuum Extract and Its Antiquorum Sensing and Antibiofilm Activity against Bacterial Pathogens

Abstract

The intensive use of antimicrobial agents has led to the emergence of multidrug resistance (MDR) among microbial pathogens. Such microbial (MDR) infections become more problematic in chronic diseases in which the efficacy of chemotherapeutic agents is highly reduced. To combat the problem of drug resistance, inhibition of bacterial quorum sensing (QS) and biofilms are considered as promising strategies in the development of anti-infective agents. In this study, gold nanoparticles (AuNPs-CA) were biofabricated using Capsicum annuum aqueous extract and characterized. The AuNPs-CA were tested against the QS-controlled virulence factors and biofilms of Pseudomonas aeruginosa PAO1 and Serratia marcescens MTCC 97. AuNPs-CA were found to be crystalline in nature with average particle size 19.97 nm. QS-mediated virulent traits of P. aeruginosa PAO1 such as pyocyanin, pyoverdin, exoprotease activity, elastase activity, rhamnolipids production, and swimming motility were reduced by 91.94, 72.16, 81.82, 65.72, 46.66, and 46.09%, respectively. Similarly, dose-dependent inhibition of virulence factors of S. marcescens MTCC 97 was recorded by the treatment of AuNPs-CA. The biofilm development and exopolysaccharide (EPS) production also decreased significantly. Microscopic analysis revealed that the adherence and colonization of the bacteria on solid support were reduced to a remarkable extent. The findings indicate the possibility of application of green synthesized gold nanoparticles in the management of bacterial infection after careful in vivo investigation.

Biosynthesis of Gold Nanoparticles and Its Effect against Pseudomonas aeruginosa

“…Our results are also in agreement with the previous studies, where baicalein fabricated nanoparticles reduced the exopolysaccharide secretion on Congo red agar plates [53]. Similar results showing the loss of exopolysaccharide production have been shown by Qais et al [54].…”

Phloroglucinol-Gold and -Zinc Oxide Nanoparticles: Antibiofilm and Antivirulence Activities towards Pseudomonas aeruginosa PAO1

“…These PG-AuNPs and PG-ZnONPs strongly reduced all forms of motility, including swarming, swimming, and twitching, suggesting that they may have virulence-attenuating characteristics (Figure 12). Although similar antivirulence effects of AuNPs and ZnONPs that were synthesized using natural extracts have been reported [62,63], information on NPs synthesized from pure natural compounds is limited. As a result, this study encourages researchers to investigate the synthesis of all forms of metallic and metal oxide nanoparticles using a purely natural compound for various biological functions.…”

Management of virulence in Pseudomonas aeruginosa and Serratia marcescens using environmentally-friendly titanium dioxide nanoparticles

“…Previously, green synthesized gold nanoparticles were reported to inhibit the pyocyanin levels in P. aeruginosa by >75% at 200 mg ml −1 . 40 Pyocyanin, another pigment with a unique blue-green colour, is directly controlled by quorum sensing in P. aeruginosa, playing a signicant role in the bacterium's virulence. 41 The synthesis of pyocyanin involves several steps, commencing with the production of autoinducer molecules and the subsequent activation of specic genes (phzA-G).…”