title: Antibiofilm Activity of Low-Amperage Continuous and Intermittent Direct Electrical Current.
abstract: Bacterial biofilms are difficult to treat using available antimicrobial agents, so new antibiofilm strategies are needed. We previously showed that 20, 200, and 2,000 μA of electrical current reduced bacterial biofilms of Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa. Here, we tested continuous direct current at lower amperages, intermittent direct current, and combinations of surface materials (Teflon or titanium) and electrode compositions (stainless steel, graphite, titanium, or platinum) against S. aureus, S. epidermidis, and P. aeruginosa biofilms. In addition, we tested 200 or 2,000 μA for 1 and 4 days against biofilms of 33 strains representing 13 species of microorganisms. The logarithmic reduction factor was used to measure treatment effects. Using continuous current delivery, the lowest active amperage was 2 μA for 1, 4, or 7 days against P. aeruginosa and 5 μA for 7 days against S. epidermidis and S. aureus biofilms. Delivery of 200 μA for 4 h a day over 4 days reduced P. aeruginosa, S. aureus, and S. epidermidis biofilms on Teflon or titanium discs. A reduction of P. aeruginosa, S. aureus, and S. epidermidis biofilms was measured for 23 of 24 combinations of surface materials and electrode compositions tested. Four days of direct current delivery reduced biofilms of 25 of 33 strains studied. In conclusion, low-amperage current or 4 h a day of intermittent current delivered using a variety of electrode compositions reduced P. aeruginosa, S. aureus, and S. epidermidis biofilms on a variety of surface materials. The electricidal effect was observed against a majority of bacterial species studied.
authors.affiliation: Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Suzannah M
authors.initials: SM
authors.lastname: Schmidt-Malan
authors.affiliation: Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Melissa J
authors.initials: MJ
authors.lastname: Karau
authors.affiliation: Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Julia
authors.initials: J
authors.lastname: Cede
authors.affiliation: Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Kerryl E
authors.initials: KE
authors.lastname: Greenwood-Quaintance
authors.affiliation: Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Cassandra L
authors.initials: CL
authors.lastname: Brinkman
authors.affiliation: Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Jayawant N
authors.initials: JN
authors.lastname: Mandrekar
authors.affiliation: Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA Division of Infectious Diseases, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA patel.robin@mayo.edu.
authors.forename: Robin
authors.initials: R
authors.lastname: Patel
mesh_terms: D000890:Anti-Infective Agents / Q000008:administration & dosage*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development*; D004560:Electricity; D011138:Polytetrafluoroethylene / Q000008:administration & dosage; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development; D013193:Stainless Steel; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000254:growth & development; D014025:Titanium / Q000008:administration & dosage
chemical_list: D000890:Anti-Infective Agents; D013193:Stainless Steel; D011138:Polytetrafluoroethylene; D014025:Titanium