Antibacterial activity of silver-nanoparticles against Staphylococcus aureus

In this study, the antibacterial activity of silver nanoparticles (Ag-NPs) as Ag-nano disc was assessed with respect to Gram positive bacteria. Scanning electron microscope (ESM) was used for Staphylococcus aureus by measuring the diameter of inhibition zones in culture media and Ag-NPS. Eventually, gauzes containing strain were further impregnated between 2-layer nanofilms at 1, 3, 5 and 7 ppm sized 2 × 2 cm and placed inside the sterile Petri dish for each. The mean diameter (mm) of the inhibition zones surrounding the discs were significantly different (p= 0.000, F=5971.57) and varied from 2.41 to 6.19 mm and the bacteria S. aureus was sensitive to all Ag-NPs concentrations. The inhibited bacterial growth for 1 ppm of Ag nanodisk (2.51±0.01 mm) was less than 3 (3.21±0.02), 5 (4.27±0.01) as well as 7 ppm (6.00±0.02 mm). It was concluded that the best concentration of Ag nanodisc that can inhibit the growth of S. aureus is 7 ppm at the size of 80-120 mm for about 24 h after inoculation.   Keywords: Staphylococcus aureus, silver nanoparticles, antibacterial activity.