112 Effects of High Voltage Pulsed Current on Bacterial Viability: An in Vitro Study

Abstract

Background and Purpose: High voltage pulsed current (HVPC) has been shown to have positive effects on wound healing due in part to proposed bacteriocidal effects in wound beds. The purpose of this study was to examine the effects of electrical stimulation (HVPC) using in vitro Streptococcus A and clinically-accepted wound care guidelines. Methods: Commercially available Streptococcus A was grown overnight in Trypticase Soy Broth. Standard 100 millimeter (mm) Petri dishes of Trypticase Soy Agar with 5% sheep blood were then streaked using sterile cotton swabs. 52 plates were subjected to 45-minutes of HVPC with the following parameters: 120 pps, 200 V, 10-second on/off cycle, and 2-second ramp time. Negative polarity was used as the active electrode. 48 control plates were prepared identically without the application of the HVPC. Zones of inhibition were measured the following day at the positive and negative electrode sites to the nearest millimeter after a 24-hour incubation period using the Kirby-Bauer method. Results: Differences were calculated using a two-way ANOVA with SPSS 11.5. Mean inhibition at the positive and negative electrodes was 0.00 mm ± 0.00 and 10.13 ± 4.13 mm, respectively. Significant between group effects were found for the control and experimental groups (F1,199 = 289.4, p < 0.001), negative and positive electrodes (F1,199 = 289.4, p < 0.001), and interaction of groups by electrodes (F1,199 = 289, p < 0.001). Conclusion: In vitro, negative polarity HVPC using clinically accepted and feasible parameters can inhibit Streptococcus A growth around the negative (active) electrode. No growth inhibition was noted around the positive (dispersive) electrode. This could provide an alternate means of infection control in assistance with wound healing.