Antibacterial Effects of Chitosan Nanoparticles Loaded with Amoxicillin and Clavulanic acid against MethicillinResistant Staphylococcus aureus Strains

Antibiotic-carrying nanoparticles have cytotoxic effects on drug-resistant bacteria. The aim of the present study was to evaluate the effect of chitosan nanoparticles carrying amoxicillin and clavulanic acid on the viability of staphylococcus aureus strains.  In this study, chitosan nanoparticles were prepared by ionic gelation method and were loaded by amoxicillin and clavulanic acid leading to the production of nanoparticles with dimension less than 100 nm. To evaluate the effect of different nanoparticle concentration on the bacteria, chitosan and amoxicillin concentrations of 0.25-8 and 1-128 µg/ml were prepared, respectively, using the microdilution method. Subsequently, 100 nm of different chitosan nanoparticle concentration with antibiotic was transferred to each well and 1 μl of bacterial suspension was added to the wells.  Turbidity in the wells was observed without armed eye and the light absorbance was read in the wavelength range of 630 nm by enzyme-linked immunosorbent assay. The results showed that minimum inhibitory concentrations of chitosan nanoparticles carrying amoxicillin and clavulanic were 0.9 and 3.6 µg/ml in susceptible and resistant specimens, respectively.  Moreover, their minimum destructive concentrations were obtained at 1.8 and 7.2 µg/ml, respectively. According to the results, the obtained combination showed more antibacterial effectiveness, compared to chitosan and amoxicillin alone. This reveals the synergistic effect of amoxicillin with clavulanic acid and chitosan.