Antibacterial Activity of Silver Nanoparticles Dispersion against Mssa and Mrsa Isolated from Wounds in a Tertiary Care Hospital of North India

Staphylococcus aureus, the main cause of nosocomial infection worldwide result in significant increases in mortality, morbidity, and cost related to prolong treatments. Silver compound has been in use since time immemorial for the treatment of burns, wounds and several other bacterial infections. In the present work, we explore the antibacterial activity of silver nanoparticles (Ag-NPs) dispersion (5-10 nm) against reference strain and clinical isolates of Methicillin-sensitive S. aureus (MSSA), and Methicillin-Resistant S. aureus (MRSA).The typical minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against standard reference strain as well as, MSSA and MRSA were observed in the range of 12-48 μg/ml and 12-96 μg/ml, respectively. The MBC/MIC ratios against all strains were found in the range of ≤1 to ≤4, which shows that Ag-NPs inhibit bacterial growth in a bactericidal rather than a bacteriostatic manner. Our finding suggests that Ag-NPs are effective broad-spectrum antibacterial agents regardless of their drug-resistance mechanisms.