The Antibacterial Activities of NiO Nanoparticles Against Some Gram-Positive and Gram-Negative Bacterial Strains

Abstract

Introduction: Given the increasing rate of antibiotic resistance among bacterial strains, many researchers have been working to produce new and efficient and inexpensive antibacterial agents. It has been reported that some nanoparticles may be used as novel antimicrobial agents.Here, we evaluated antibacterial properties of nickel oxide (NiO) nanoparticles. Methods: NiO nanoparticles were synthesized using microwave method. In order to control the quality and morphology of nanoparticles, XRD (X-ray diffraction) and SEM (scanning electronmicroscope) were utilized. The antibacterial properties of the nanoparticles were assessed against eight common bacterial strains using agar well diffusion assay. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were measured. Antibiotic resistance pattern of the bacteria to nine antibiotics was obtained by Kirby-Bauer disk diffusion method. Results: The crystalline size and diameter (Dc) of NiO nanoparticles were obtained 40-60 nm. The nanoparticles were found to inhibit the growth of both gram-positive and gram-negative bacteria with higher activity against gram-positive organisms. Among bacterial strains, maximum sensitivity was observed in Staphylococcus epidermidis with MIC and MBC of 0.39 and 0.78 mg/mL, respectively. The bacteria had high resistance to cefazolin, erythromycin, rifampicin,ampicillin, penicillin and streptomycin.Conclusion: NiO nanoparticles exhibited remarkable antibacterial properties against gram positive and gram-negative bacteria and can be a new treatment for human pathogenic and antibiotic-resistant bacteria.