New Approach For Simvastatin As An Antibacterial: Synergistic Effect With Bio-Synthesized Silver Nanoparticles...

Multidrug-resistant bacteria such as extended-spectrum beta-lactamase (ESBL), Enterobacteriaceae, and methicillin-resistant Staphylococcus aureus (MRSA) pose a challenge to the human health care system. MRSA is among the major causes of hospital-acquired and community infections.

Therefore, in the present study, we evaluated the antibacterial activity of silver nanoparticles synthesized by Fusarium oxysporum (AgNP_bio) in combination with simvastatin against reference and multidrug-resistant bacterial strains.

Simvastatin showed a minimal inhibitory concentration (MIC) ranging from 0.062 to 0.25 mg mL^-1 against MRSA. AgNP_bio with a size of 77.68± 33.95 nm and zeta potential -34.6 ± 12.7 mV showed an MIC of 0.212 mg mL^-1 against S. aureus including MRSA strains. The checkerboard assay and time-kill curves exhibited a synergistic effect of the simvastatin-AgNP_bio combination on antibacterial activity against MRSA strains. The combination of simvastatin and AgNP_bio demonstrated antibacterial activity against Escherichia coli producing ESBL. Scanning electron microscopy showed the formation of cell surface protrusions after treatment with AgNP_bio and the formation of a large amorphous mass after treatment with simvastatin, both in MRSA.

Our results indicate that the combination of AgNP_bio and simvastatin could be a great future alternative in the control of bacterial infections, where, when combined with simvastatin, smaller doses of AgNP_bio are required, with the same antibacterial activity.