Antibacterial Effects of a Silver Electrode Carrying Microamperage Direct Current in vitro

Currently, electrical stimulation is an accepted method used clinically to promote chronic wound healing. A literature review revealed that similar therapeutic current has been shown to suppress growth of common wound pathogens in vitro and in vivo. To date, little has been reported on the factors contributing to the antibacterial effects of microamperage direct current (μADC) stimulation. The purpose of this project was to investigate the role of electric field strength, current density, pH, and type of electrode used in vitro, to gain a better understanding of how these factors contribute to inhibiting growth of select wound pathogens. μADC was applied via silver electrodes at amplitudes ranging from 26 μA to 800 μA in an in vitro system consisting of Staphylococcus aureus and Pseudomonas aeruginosa. Results suggest that transmission of μADC by silver wire inhibits bacterial growth around the anode, and that the area of inhibition is directly proportional to the size of the electrode used. Current amplitude (as a function of electric field strength and current density) and pH did not seem to cause the antibacterial effects observed in this study