effect of zinc oxide nanoparticles on loaded antibiotics against multidrug-resistant acinetobacter spp.

Background: metal oxide nanoparticles (nps) have shown promising efficacy for combating bacterial resistance due to their antibacterial properties. this research investigated the effect of zinc oxide nps (zno-nps) on the antibacterial activity of conventional antibiotics including ciprofloxacin (cip), cefotaxime (ctx), and colistin (cst) against multidrug-resistant acinetobacter isolates. methods: the disc diffusion method was performed to detect the pattern of antibiotic resistance in isolates. the synthesized zno-nps via the solvothermal method were characterized by field emission scanning electron microscopy (fesem), x-ray diffraction (xrd), and energy-dispersive x-ray spectroscopy (eds). finally, the broth microdilution technique was conducted to demonstrate the antibacterial activity of cip, ctx, and cst antibiotics with and without a sub-inhibitory concentration of zno-nps. results: xrd, eds, and fesem results confirmed the crystalline structure of zno-nps, and the average size was 100±58.68 nm. all isolates were discovered to be of multidrug-resistant (mdr) type and fully susceptible to cst. the antibacterial activity of ctx and cip was restored when combined with a sub-inhibitory level of zno-nps (0.25 mg/l), and the highest activity was obtained at the concentrations of 32 μg/ml ctx and 8 μg/ ml cip. eventually, zno-nps showed a synergistic effect on the antibacterial properties of cst against mdr acinetobacter. conclusions: this research indicated that the combination of zno-nps with some common antibiotics can be considered as a novel strategy for reducing the spread of antibiotic-resistant bacteria