Silver Nanoparticles Derived from Albizia lebbeck Bark Extract Demonstrate Killing of Multidrug-Resistant Bacteria by Damaging Cellular Architecture with Antioxidant Activity

摘要

abstract_textpSilver nanoparticles (Ag-NP-AE) are synthesized and stabilized by the extract of an ethnomedicine, Albizia lebbeck bark aqueous extract (AE). Ag-NP-AE is active against several multidrug-resistant (MDR) clinical isolates. The nanoparticles are characterized by UV-vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), Dynamic light scattering (DLS), Scanning electron microscope (SEM), Transmission electron microscope (TEM) and X-ray diffraction (XRD) studies. The antibacterial potency of Ag-NP-AE is determined by Disc diffusion, Agar and Broth dilution assays against 14 MDR isolates along with their minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The growth kinetics was determined by quantification of colonies; while toxicity by quantification of viable cells. The Ag-NP-AE shows free-radical scavenging activity at 15-20 mu M and is non-toxic up to 50 mu M but demonstrated significant antibacterial activity against all the test isolates with zone diameter of 10.4-19.5 mm and MIC of 0.5-0.84 mu M (0.085-0.143 mu g); while the zone diameter with AE was 10.2-15 mm and MIC of 128-1024 mu g/mL, respectively; while 100 killing was observed at 0.50 mu M within 2-4 h of exposure due to damage of cellular architectures./p/abstract_text