Antibacterial Control of an Extremely Low Frequency Electric Field on Escherichia coli

Abstract

The aim of this study was to investigate the electric field frequency and the time of exposure that causes maximum inhibition of Escherichia coli (E. coli) growth. Methods and Results: Bacterial suspensions were subjected to an extremely low frequency electric field (ELFEF) with a 0.1 Hz interval between 0.2 Hz and 0.4 Hz. The bacterial growth was observed through optical density (OD) readings. OD values were taken every hour for four hours to monitor bacterial growth in both exposed and unexposed samples. The antibiotic susceptibility test was done to determine the difference between the susceptibility of both exposed and unexposed bacterial samples. Structural changes in the exposed bacterial samples were monitored by transmission electron microscope (TEM). The bacterial growth curve revealed a highly significant growth inhibition after being exposed to 0.2 Hz at 2 hours’ exposure time. E. coli suspension exposed to ELFEF at inhibition frequency 0.2 Hz showed a significant increase in susceptibility to antibiotics Keflex, meropenem, and piperacillin-tazobactam. The current data suggest that treating E. coli with 0.2 Hz for 2 hours is an effective, prospective, and novel technique for reducing cellular growth and dramatic alteration in the cell membrane. TEM clarified the great destruction of the bacteria cell wall.

Keywords

• extremely low frequency electric field
• e. coli
• optical density
• transmission electron microscope