Evaluations of the effects of extremely low-frequency electromagnetic fields on growth and antibiotic susceptibility of escherichia coli and pseudomonas aeruginosa

We aimed to investigate the effects of exposure to extremely low-frequency electromagnetic fields (2mT; 50Hz) on the growth rate and antibiotic sensitivity of E. coli ATCC 25922 and P. aeruginosa ATCC 27853. The electromagnetic field treatment significantly influenced the growth rate of both strains when incubated in the presence of subinhibitory concentrations of kanamycin (1g/mL) and amikacin (0.5g/mL), respectively. In particular, at 4, 6, and 8h of incubation the number of cells was significantly decreased in bacteria exposed to electromagnetic field when compared with the control. Additionally, at 24h of incubation, the percentage of cells increased (P. aeruginosa 42 ; E. coli 5 ) in treated groups with respect to control groups suggesting a progressive adaptive response. By contrast, no remarkable differences were found in the antibiotic susceptibility and on the growth rate of both bacteria comparing exposed groups with control groups. © Copyright 2012 B. Segatore et al.