Abstract
Staphylococcus aureus is one of the most important etiological agents in community-acquired nosocomial infections. This bacteria produces several virulence factors, including biofilm formation ability, which make difficult to treat infections, especially those from medical devices. Statins are one of the most prescribed drugs in the world and its effects go beyond lipid-lowering drugs, called pleiotropic effects. The prominent simvastatin in previous studies has shown antimicrobial activity against gram-positive bacteria, including S. aureus and gram-negative pathogens. As with simvastatin, silver nanoparticles (AgNP) have known antimicrobial activity. In addition, studies have shown that associations between AgNP and antimicrobial drugs such as penicillin, amoxicillin, erythromycin, clindamycin and vancomycin were satisfactory, since these associations may these drugs to specific targets, and potentiate their effect by reducing the resistance of microrganisms. The present project aim to the evaluate the antibacterial effects of simvastatin and AgNP, alone or in combination, against the clinical strains of Staphylococcus aureus. The AgNP will be biosynthesised by Fusarium oxysporum, and its formation accompanied by spectrophotometry. The characterization of AgNP will be performed by dynamic light scattering (DLS), Energy-dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). The antimicrobial activity of AgNP, simvastatin and the two-drug combination will be investigated in Minimum Inhibitory Concentration (MIC) assays, Checkerboard assay and biofilm inhibition assays in clinical strains of S. aureus. As a hypothesis, we expect both simvastatin and AgNP to exhibit antimicrobial activity against S. aureus, and that when associated, the antimicrobials have a synergistic effect.
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