The effect of exposure to non-ionising radiofrequency field on Escherichia coli, Klebsiella oxytoca and Pseudomonas aeruginosa biofilms

ABSTRACT

An environment with a higher accumulation of electromagnetic non-ionising radiofrequency (RF) emissions generated by various telecommunication, data transport and navigation devices (mobile phones, Wi-Fi, radar, etc.) may have a major impact on biological systems. This study aimed to evaluate the incidence of an electromagnetic field (EMF) on the development of bacterial biofilm. Quantification of biofilm production was done by using microtiter plate assay. Bacterial isolates of Escherichia coli, Klebsiella oxytoca and Pseudomonas aeruginosa were exposed with EMF of frequencies 1–5 and 2.4 GHz with an exposure time 3 or 24 h, respectively. Exposure of bacteria to EMF produced a statistically significant increase in biofilm production mainly at 1, 2 and 4 GHz, and in contrast, a significant inhibition of biofilm development occurred at frequencies 3 and 5 GHz, both with exception of K. oxytoca and P. aeruginosa. Wi-Fi operating at 2.4 GHz caused biofilm reduction. The results indicate that EMF exposure act on bacteria in both ways, depending on the frequency: as stressful by enhancing bacterial biofilm formation (under environmental stress, bacteria produce a polysaccharide matrix and aggregate to form biofilms to increase virulence and resistance), although some frequencies leading to biofilm damage could be caused by changes to the physicochemical properties of bacteria.

GRAPHICAL ABSTRACT

Graphic description of the experiment.

KEYWORDS:

• Electromagnetic field
• mobile phones
• Wi-Fi
• bacterial biofilm

Acknowledgements

The authors thank to Dr L. Bírošová from Slovak Technical University, Department of Nutrition and Food Quality Assessment in Bratislava and Veterinary and Food Institute (Dolný Kubín, Slovakia) for kindly provided of bacteria (Pseudomonas aeruginosa and Klebsiella oxytoca).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article.

Additional information

Funding

This work was supported by the Slovak VEGA under grant number [2/0010/21].