The Combined Effect of Copper Oxide and Magnesium Oxide Nanoparticles Against Water and Food Borne Bacteria

Background: The incidence of foodborne infectious diseases has been stable and even increased in many countries. Improper use of antibiotics due to the prevalence of microbial diseases has caused drug resistance. So nanotechnology has many attractive applications in the food industry, such as food preservation and food quality control. By the reason, the absorptive and antibacterial features of copper oxide nanoparticles combining with magnesium oxide nanoparticles in killing the bacteria were investigated. Materials and Methods: The antibacterial activities of CuO NP in combination with MgO NP against Escherichia coli and Staphylococcus aureus in culture media and fruit juice (mango, pomegranate, and peach) by agar diffusion and colony count method were explored. Electron microscopy was used to characterize the morphological characteristics of the bacteria tested after treatment with CuO and MgO NPs. Results: The results of one-way ANOVA by 95% confidence showed that CuO and MgO NPs have antimicrobial activity on E. coli and S. aureus. An effect of synergism was observed when combining CuO and MgO NP. Electron microscopy photographs showed that treatment with the combination of MgO and CuO caused damage to the cell membrane. As a result, the leakage of intracellular contents kills the bacteria. Conclusion: The combination of CuO and MgO nanoparticles can successfully control the growth of E. coli and S. aureus in liquid and juice medium. So, this combination treatment can reduce the required amount of CuO and MgO nanoparticles during the pathogen control process in the food industry.