Minimum Inhibitory Concentration (MIC) and Minimum Bacterial Concentration (MBC) Evaluation of Green Synthesised Silver Nanoparticles on Staphylococcus aureus and Streptococcus agalactiae

Abstract

In the present study silver nanoparticles were green synthesised using leaf extract of Moringa oleifera and fruit extract of Tamarindus indica. They were characterised and evaluated for Minimum Inhibitory Concentration and Minimum Bacterial Concentration on Staphylococcus aureus and Streptococcus agalactiae. 66 (66%) and 27 (27%) of the 100 milk samples obtained from various sources tested positive by the culture method for Staphylococcus aureus and Streptococcus agalactiae, respectively. Silver nanoparticles prepared with leaf extract of Moringa oleifera and fruit extract of Tamarindus indica showed a Minimum Inhibitory Concentration (MIC) of 0.312 mg/ml on Staphylococcus aureus in both extracts and MIC of silver nanoparticles on Streptococcus agalactiae was at 0.312 mg/ml and 0.625 mg/ml concentration when prepared with Tamarind and Moringa extracts respectively. Staphylococcus aureus and Streptococcus agalactiae did not grow in any concentrations of the Minimum Bacterial Concentration (MBC), proving that it is bactericidal.