Journal of Rehabil itation Research & Development A comparison of four electrical stimulation types on Staphylococcus aureus growth in vitro

Abstract—We evaluated the efficacy of common electrical stimulation (ES) types on bacterial growth in vitro using clini-cally relevant conditions. Four types of ES—continuous micro-amperage direct current (µADC), high-voltage pulsed current (HVPC), low-voltage monophasic milliamperage pulsed cur-rent (LVMmAPC), and low-voltage biphasic milliamperage pulsed current (LVBmAPC)—were each applied to a separate set of culture plates containing Staphylococcus aureus for 1 h at 37 ºC on three consecutive days. After ES treatment, the zone of inhibition surrounding each electrode was measured. Zone of inhibition measurements showed a significant inhibi-tory effect for continuous µADC and HVPC (p < 0.05), but not for LVMmAPC and LVBmAPC. Differences in bacterial growth inhibition were not found for polarity and time. These data suggest that for infected wounds, HVPC and continuous µADC treatments may have an initial bacterial inhibitory effect, which does not significantly change with subsequent treatments. Key words: bacteria, electrical stimulation, wound healing. buildup [9]. The influence of ES on wound healing has been assessed in a number of clinical trials that examined continuous microamperage direct current (µADC) [10,11], pulsed µADC [12,13], pulsed milliamperage direct current (mADC) [14–16], and high-voltage pulsed current (HVPC) [17–21], all of which have demonstrated evidence of decreased wound healing time by using ES. According to the clinical practice guidelines devel-oped by the U.S. Department of Health and Human Ser-vices Agency for Healthcare Research and Qualit