Evaluation of the Inhibitory Effects of Zinc Oxide Nanoparticles on Biofilm Formation of Some Foodborne Bacterial Pathogens

Background and Aims: One of the most important factors in food industry is the formation of microbial biofilm which can be the potential source of food products contamination with food spoilage and foodborne pathogenic bacteria. This study was conducted to evaluate the inhibitory effects of zinc oxide nanoparticles on biofilm formation of some foodborne bacterial pathogens. Materials and Methods: This research was carried out in ۲۰۱۵. Minimum inhibitory concentration (MIC) of zinc oxide nanoparticles for E. coli (ATCC ۳۵۲۱۸), Staphylococcus aureus (ATCC ۶۵۳۸), Salmonella typhimurium (ATCC ۱۴۰۲۸) and Bacillus cereus (ATCC ۱۴۵۷۹) was determined by using ۹۶-well microplate and resazurin reduction method. Biofilm formation inhibition was assessed with microtiter plate method based on crystal violet staining and measurement of optical density using microplate reader. Results: MIC of zinc oxide nanoparticles for the above mentioned bacteria was respectively ۱, ≤ ۰.۵, ۱ and ۲ mg/mL. The inhibition percentages of biofilm formation at the MIC of the nanoparticles were ۹۰.۲۰, ۸۵.۶۹, ۸۳.۶۵ and ۶۱.۹۶, respectively. Conclusions: In this study, zinc oxide nanoparticle showed the ability to inhibit the formation of biofilm even in sub inhibitory concentrations or Sub-MICs.  No significant difference (P>۰.۰۵) was observed in the biofilm inhibitory effects of ZnO nanoparticles at MIC and ۱/۲×MIC between E. coli and S. aureus. Results of this study showed the inhibitory effects of zinc oxide nanoparticles on biofilm formation of the studied foodborne bacterial pathogens. According to the importance of these bacteria in public health, ZnO nanoparticle can be used as a cleaning agent for the surfaces, apparatus and production lines in food plants in order to prevent foodborne bacterial biofilm formation.

Keywords:

Biofilm , Foodborne bacterial pathogen , Inhibitory effect , Zinc oxide nanoparticle , اثر مهاری , باکتری بیماری زای غذازاد , بیوفیلم , نانو ذره اکسید روی