Antibacterial Activity and Acute Toxicity Testing of Biosynthesized Silver Nanoparticles against Methicilin-Resistant Staphylococcus aureus and Pseudomonas aeruginosa

Abstract

Antibacterial activity of biosynthesized silver nanoparticles was studied using the macrobroth dilution technique. The silver nanoparticles was significantly active (p > 0.05) against the test organisms at an extract concentration of 75 {micro}g/ml. Concentrations [≤] 50 {micro}g/ml were not as effective as the colony forming units at this concentration, 1.61 x 106 for methicillin-resistant Staphylococcus aureus and concentrations [≤] 25 {micro}g/ml 1.45 x 106 for Pseudomonas aeruginosa respectively, were about the same range as the colony forming units of the controls. The silver nanoparticles inhibited Methicillin-Resistant S. aureus more (MIC of 75 {micro}g/ml and MBC of 100 {micro}g/ml) than they inhibited P. aeruginosa (both MIC and MBC was 100 {micro}g/ml). The LD50 of the synthesized silver nanoparticles after oral administration was seen to be greater than 5000 mg/kg body weight and is therefore thought to be safe. This study supports the use of silver nanoparticles as therapeutic agents.