(279e) Toward to the Design of an Electrochemical Therapy (ECT) Against Microbial Infection

One of the main challenges healthcare faces is the preponderance of antibiotic-resistant microorganisms in public and medical environments. The antibiotic-resistant species constitute significant challenges to curing chronic infections, especially those associated with implanted medical devices. We explore the antimicrobial activity of low-level electrochemical treatments on a range of microorganisms. We report that these pathogenic microbes can be effectively eliminated by low-level direct currents (DCs); e.g. treatment with 70 μA/cm² DC for 1 hr using titanium or stainless steel (SS) 304 electrodes reduced the number of viable planktonic Streptococcus mutans, Candida albicans, Pseudomonas aeruginosa by 1-2 logs, compared to the untreated control. In addition to killing by applying DC alone, synergistic effects are achieved when treating the planktonic and biofilm cells with 70 μA/cm² DC and antibiotic dosages concurrently. Interestingly, alternative ECT utilizing DC generated with graphite followed sequentially by 1.5 μg/mL Tob, or DC via TGON 805 (a carbon-based material) as a sole factor, eradicated the persisters completely (~7-log). Electrochemical factors including electrode composition, electrochemical byproducts, and current/potential levels contributed to impairment of persisters’ electrophysiology, causing substantial changes in cell structures and transcriptomes. This work will define the conditions necessary to modulate electrochemically-induced sensitization of pathogens and eradicate polyspecies biofilms from implantable materials.