Biologically synthesized silver nanoparticles enhances antibiotic activity against Gram-negative bacteria

Here we report a simple, fast, cost-effective, and nonpolluting approach for synthesis of silver nanoparticles (AgNPs) using leaf extract of Typha angustifolia. We demonstrate the dose-dependent antibacterial activity of AgNPs and different antibiotics against Escherichia coli and Klebsiella pneumoniae. Furthermore, we demonstrate the efficacy of AgNPs in combination with various broad-spectrum antibiotics against E. coli and K. pneumoniae. The results show that combinations of antibiotics and AgNPs show significant antimicrobial effects at sub-lethal concentrations of the antibiotics. These data suggest that combinations of antibiotics and AgNPs can be used therapeutically for the treatment of infectious diseases. (C) 2015 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.