Effect of silver nanoparticles on the antibacterial activity of Levofloxacin against methicillin-resistant Staphylococcus aureus.

OBJECTIVE The paper presents the antibacterial activity of silver nanoparticles (AgNPs) when conjugated with Levofloxacin. The AgNPs used in this study were synthesized from silver nitrate using sodium borohydride as a reducing agent. MATERIALS AND METHODS Levofloxacin activity was determined by minimum inhibitory concentrations (MICs) and also the erythrocyte hemolytic assay determined the capability of conjugation to cause hemolysis in human erythrocyte. RESULTS The synthesis of levofloxacin-AgNP conjugates was confirmed by ultraviolet/visible (UV/vis) spectroscopy. A peak absorption value between 400-450 nm for the extract and the color change to dark brown were corresponding to the plasmon absorbance of AgNPs. On the other hand, levofloxacin-AgNPs could be effective against methicillin-resistant Staphylococcus aureus (MRSA). The MICs of levofloxacin and levofloxacin-AgNPs were 12 and 10 µM, respectively. CONCLUSIONS These findings indicated that levofloxacin-AgNPs had an effective bactericidal activity against the bacterial MRSAs. This conjugation appeared to inhibit bacterial adaptive capabilities, which leads to inhibition of bacterial resistance.