In Vitro Assessment of Electric Currents Increasing the Effectiveness of Vancomycin Against Staphylococcus epidermidis Biofilms

Abstract

Biofilms are communities of bacteria that can cause infections which are resistant to the immune system and antimicrobial treatments, posing a significant threat for patients with implantable and indwelling medical devices. The purpose of our research was to determine if utilizing specific parameters for electric currents in conjunction with antibiotics could effectively treat a highly resistant biofilm. Our study evaluated the impact of 16 μg/mL of vancomycin with or without 22 or 333 μA of direct electric current (DC) generated by stainless steel electrodes against 24-, 48-, and 72-h-old Staphylococcus epidermidis biofilms formed on titanium coupons. An increase in effectiveness of vancomycin was observed with the combination of 333 μA of electric current against 48-h-old biofilms (P value = 0.01) as well as in combination with 22 μA of electric current against 72-h-old biofilms (P value = 0.04); 333 μA of electric current showed the most significant impact on the effectiveness of vancomycin against S. epidermidis biofilms demonstrating a bioelectric effect previously not observed against this strain of bacteria.

Electrical stimulation disrupts biofilms in a human wound model and reveals the potential for monitoring treatment response with volatile biomarkers

“…ES may increase the efficacy of antibiotics, a concept termed the “bioelectric effect”; and this has been shown in the majority of studies to date which have used DC . Many have shown an enhancing effect of ES on the efficacy of antimicrobials in vitro although we were not able to demonstrate this in vitro or ex vivo in the present study. However, we only assessed the bioelectric effect against one species at a single time point with the use of a single antibiotic agent at a high, fixed concentration.…”

“…Antibiotic‐specific bioelectric effects have been shown previously where certain antibiotics were enhanced with the addition of ES, whereas others had no increased efficacy against Pseudomonas biofilms. Variations in intensity of the currents can also enhance the bioelectric effect; however, caution must be applied as there will be limitations on the ES parameters deemed safe for use in the clinical setting. The applied electric field we used corresponds to the endogenous “current of injury” which is the lateral electrical field that is generated through the wound following an injury to the skin, thought to be significant in initiating repair and deemed safe in the clinical environment …”

Bacterial biofilm formation on implantable devices and approaches to its treatment and prevention

“…For this reason, electric and electromagnetic fields are being currently investigated for the treatment of bacterial colonization. The application of electrical methods to treat biofilms such as DC voltage [116], low AC currents, pulsed electric fields, capacitive coupling treatment, and extremely low-frequency electromagnetic waves (ELF-EMF) are said to be electricidal [117]. When these methods are used in combination with antibiotics or with host immune responses to create synergistic effect, it is termed a bioelectric effect [116, 117].…”

Oral Microbes, Biofilms and Their Role in Periodontal and Peri-Implant Diseases

“…Furthermore, the use of bacteriophages (viruses that contaminate bacterial cells) [ 108 ], antimicrobial peptides [ 109 ] or photodynamic therapy [ 110 ] have also been investigated in the past decade as innovative antibiofilm strategies. Finally, among the numerous antibiofilm approaches that have been suggested, an interesting electrical enhancement of the effects of several antibiotics and industrial biocides have been described against different types of bacterial biofilms [ 111 , 112 , 113 ]. Electric currents have also been reported to have a bactericidal effect [ 114 ] in addition to detaching adherent bacteria [ 115 ] and preventing their adhesion [ 116 ].…”