Bio-inspired facile fabrication of silver nanoparticles fromin vitrogrown shoots ofTamarix nilotica: explication of its potential in impeding growth and biofilms ofListeria monocytogenesand assessment of wound healing ability

摘要

Novel, safe, and effective antilisterial agents are required in order to preventListeria monocytogenesinfections and maintain food safety. This study synthesized silver nanoparticles (AgNPs) from the shoot extract ofin vitro-grownTamarix nilotica(TN) and characterized them using X-ray diffraction, Fourier transform infrared spectroscopy, UV-visible spectroscopy, dynamic light scattering, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXS), and transmission electron microscopy (TEM). We also assessed the antilisterial potential of the synthesized TN-AgNPs by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against two strains ofL. monocytogenesandL. innocua. TN-AgNPs (2xMICs) showed a significant decrease in growth in allListeriatest strains. Release of cellular content and cell morphology analysis of TN-AgNP-treated bacterial cells demonstrated the mechanism of bactericidal activity of AgNPs. In addition, TN-AgNPs induced a significant decrease in swimming motility (62-71%), biofilm formation (57-64%), and preformed biofilms (48-58%) in allListeriatest strains at sub-inhibitory concentrations. Microtitre plate assay results for biofilm inhibition were confirmed by SEM and CLSM visualization of TN-AgNP-treated and TN-AgNP-untreatedListeriatest strains. TN-AgNPs also showed wound-healing activity in MCF-7 cells by inhibiting cell migration in a scratch plate assay. TN-AgNP-induced enhanced reactive oxygen species generation in treated cells could be a plausible reason for the biofilm inhibitory activity of AgNPs. TN-AgNPs having antilisterial, antibiofilm, and wound-healing properties can be effectively used to preventL. monocytogenesinfections in the food industry and healthcare.