Effects of magnesium oxide and copper oxide nanoparticles on biofilm formation of Escherichia coli and Listeria monocytogenes

Abstract

Biofilms formed in food-processing environments are of special importance as they have the potential to act as a persistent source of microbial contamination that may lead to food spoilage or transmission of diseases. The creation of microbial biofilms, which can be a source of food product contamination with food spoilage and foodborne pathogenic bacteria, is one of the most critical elements in the food industry. The goal of this study was to see how well magnesium oxide (MgO) and copper oxide (CuO) nanoparticles (NPs) inhibited growth and biofilm formation of two common foodborne bacterial pathogens. This study was completed in the year 2020. Resazurin reduction and micro-dilution procedures were used to assess the minimum inhibitory concentration (MIC) of magnesium oxide and copper oxide nanoparticles for Escherichia coli O157: H7 (ATCC 35 218) and Listeria monocytogenes (L. monocytogenes) (ATCC 19 118). The bacterial adhesion to hydrocarbon technique was used to determine the cell-surface hydrophobicity of the selected bacteria. The surface assay was also used to calculate the influence of the NPs coated surfaces on the biofilm formation of the selected bacteria. Magnesium oxide nanoparticles had MICs of 2 and 2 mg ml−1, while copper oxide nanoparticles had MICs of 0.16 and 1 mg ml−1 against E. coli and L. monocytogenes, respectively. At the MIC, the magnesium and copper nanoparticles inhibited biofilm formation of E. coli and L. monocytogenes by 89.9 and 96.6 percent and 93.6 and 98.7 percent, respectively. The hydrophobicity of E. coli and L. monocytogenes was determined to be 74% and 67%, respectively. The surface assay revealed a substantial reduction in bacterial adhesion and colonization on NPs-coated surfaces. Both compounds had inhibitory effects on E. coli and L. monocytogenes, according to our findings. Even at sub-MICs, NPs were found to be able to prevent biofilm development. The microbial count and production of microbial biofilms were reduced on surfaces coated with MgO and CuO nanoparticles. MgO and CuO nanoparticles can be utilized as a cleaning agent for surfaces to avoid the formation of foodborne bacterial biofilms, which is important for public health.