Effect of electric current in viability, biofilm formation and antibiotic resistance of Pseudomonas aeruginosa : A systematic review

The bactericidal effect of electric current has been studied in various microorganisms such as Pseudomonas aeruginosa. The objective of this review is to identify the experimental parameters with the greatest antibacterial effect in the shortest time. Literature search was conducted in the databases PubMed, Science Direct, and Google Scholar. Only original articles published between 2014 and 2023 were included, where the effect of electric current on viability, biofilm formation, and/or antibiotic resistance in P. aeruginosa was analyzed. Quality control criteria considered included specifying control and experimental groups, replicates performed, experimental parameters, and study limitations. Ten studies were included, which involved the strains Xen5, Xen41, PAO1 persistent cells, and PA14. An average reduction of 3.5 log in biofilm formation was observed in the included studies. The electric current parameters that achieved the greatest effect were 500 μA DC with platinum electrodes for 4 days [5.2–5.5 log], 200 μA intermittent with titanium electrodes for 4 days [4.99 log], and 150 ± 60 μA with silver electrodes for 24 h [4 log]. Complete eradication of PAO1 persistent cells was achieved in 1 h with a treatment of 70 μA/cm2 DC followed by 1.5 μg/mL tobramycin for 1 h each. The bactericidal effect of electric current is proportional to the exposure time and current intensity. The electrode material influences the effectiveness of the treatment, possibly because of redox reactions, while differences are observed in the effect on the cell membrane and gene expression when using metallic or carbon electrodes, suggesting differences in the mechanism of action.