Evaluation of Wi-Fi Radiation Effects on Antibiotic Susceptibility, Metabolic Activity and Biofilm Formation by Escherichia Coli O157H7, Staphylococcus Aureus and Staphylococcus Epidermis

Background: The radiation emitted from electromagnetic fields (EMF) can cause biological effects on prokaryotic and eukaryotic cells, including non-thermal effects. Objective: The present study evaluated the non-thermal effects of wireless fidelity (Wi-Fi) operating at 2.4 GHz part of non-ionizing EMF on different pathogenic bacterial strains ( Escherichia coli O157H7 , Staphylococcus aureus, and Staphylococcus epidermis). Antibiotic resistance, motility, metabolic activity and biofilm formation were examined.  Materials and Methods: A Wi-Fi router was used as a source of microwaves and also bacterial cells were exposed to Wi-Fi radiation continuously for 24 and 48 hours. The antibiotic susceptibility was carried out using a disc diffusion method on Muller Hinton agar plates. Motility of Escherichia coli O157H7 was conducted on motility agar plates. Cell metabolic activity and biofilm formation were performed using 3-(4, 5-Dimethylthiazol-2yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and crystal violet quantification, respectively. Results:  The exposure to Wi-Fi radiation altered motility and antibiotic susceptibility of Escherichia coli O157H7. However, there was no effect Wi-Fi radiation on antibiotic susceptibility of Staphylococcus aureus and Staphylococcus epidermis . On the other hand, the exposed cells, as compared to the unexposed control, showed an increased metabolic activity and biofilm formation ability in Escherichia coli O157H7 , Staphylococcus aureus and Staphylococcus epidermis. Conclusion: These results proposed that Wi-Fi exposure acted on bacteria in stressful manner by increasing antibiotic resistance and motility of Escherichia coli O157H7, as well as enhancing biofilm formation by Escherichia coli O157H7 , Staphylococcus aureus and Staphylococcus epidermis . The findings may have implications for the management of serious diseases caused by these infectious bacteria.