Is it time for a ‘shocking’ new way to kill microbes?

Researchers from University of Pittsburgh are utilizing electrochemical therapy in order to boost the ability of antibiotics to eradicate bacteria and fungi, following a specific type of surgery – the fitting of titanium implants.

Titanium is used for many types of implants due to its low density and good biomechnanical strength-to-weight ratio. Furthermore, the metal is corrosion resistant which makes it especially suitable for joint replacement.

A risk arises when implants are fitted since the smooth surfaces provide opportunities for microbes to attach to and to form biofilms. These slime-like communities can trigger chronic infections and inflammation.

Polymicrobic biofilm grown on a stainless steel surface in a laboratory potable water biofilm reactor for 14 days, then stained with 4,6-diamidino-2-phenylindole (DAPI) and examined by epifluorescence microscopy. Bar, 20 µm.

Ricardo Murga and Rodney Donlan / Centers for Disease Control and Prevention

To combat this a new treatment has been devised, based on electrochemical therapy, as Dr. Niepa, who led the study, explains: “With this technique, the current doesn’t discriminate as it damages the microbe cell membrane. It’s more likely that antibiotics will be more effective if the cells are simultaneously challenged by the permeabilizing effects of the currents. This would allow even drug-resistant cells to become susceptible to treatment and be eradicated.”

The technique uses a relatively weak electrical current which is directed at the metal-based implant. As the current moves through the implant, it functions to break the cell membrane of any attached microorganisms. The current is set so that it can inflict damage to bacteria and fungi but so that it does not harm human body tissue.

The damage to the cell membrane then makes the microbes more susceptible to antibiotics. This is because antibiotics are less effective at killing dormant bacterial cells (rather than cells that are growing and dividing). The effect of electrochemical stress on bacterial dells serves to sensitize them, and this makes them susceptible to antibiotics.

A strain of Candida auris cultured in a petri dish at CDC.

Shawn Lockhart/CDC

The research to date has been conducted on the fungus Candida albicans in relation to dental implants. Further research will look at other microorganisms and other types of titanium-based implants.

The research has been published in the journal ACS Applied Materials & Interfaces, with the research paper titled “Electrochemical Strategy for Eradicating Fluconazole-Tolerant Candida albicans using Implantable Titanium.”