Abstract
The emergence of antibiotic-resistant bacteria has become a serious threat to human health and continues to account for high rates of mortality. Thus, many studies have been conducted to improve conventional antimicrobial agents. Currently nanoparticles (NPs) are deemed as potent antibacterial agents with the ability to enhance the antimicrobial activity of various antibacterial products. This study was aimed at assessing the ability of naturally occurring and synthetic heterocyclic compounds to cap metallic nanoparticles and to evaluate their antibacterial potency against gram- negative bacteria.
To achieve the aim, gold (Au), and silver (Ag) nanoparticles, capped with novel naturally occurring and synthetic heterocycles were synthesized. All the synthesized nanoparticles were then characterized using: Ultraviolet-visible spectroscopy (UV– Vis), Dynamic Light Scattering (DLS), Fourier transform infrared (FTIR), Transmission Electron Microscopy (TEM) and Energy Dispersive x-ray Spectroscopy (EDS). Post characterization, a resazurin rapid screening test was used to evaluate the antibacterial potency of all the materials against six gram-negative bacterial strains (Proteus vulgaris, Klebsiella oxytoca, Pseudomonas aeruginosa, Proteus mirabilis; Escherischia coli and Klebsiella pneumonia).
The outcomes of this study demonstrate the feasibility of using both naturally occurring and synthetic heterocyclic compounds as capping agents of AuNPs and AgNPs to fulfil the growing demand for rapid, convenient, and non-hazardous NPs.This results further shows that these types of nanoparticles are potent against gram-negative bacteria. Moreover, this study demonstrates the ability of nanoparticles to potentiate the activity of heterocyclic compounds against some of the tested strains. For future recommendation, an In vivo cytotoxic effect of the AuNPs and AgNPs capped with naturally occurring and synthetic heterocycles should be assessed in an animal model for establishing the true cytotoxic activity in a living system.
Keywords: Antibiotic resistance, heterocyclic compounds, and metallic nanoparticles.