Low level electric shocks to the skin could be an alternative to antibiotics to prevent wound infections, new research suggests.
For the first time, researchers from the US found imperceptible electric shocks delivered through a specially designed skin patch can stop bacterial infections.
The team set out to discover if electricity could be used to manipulate bacteria as an alternative to antibiotics in the face of the global antibiotic resistance crisis.
Due to antibiotic overuse, many microbes have evolved and become resistant to current antibiotics, often referred to as superbugs.
One of those microbes is Staphylococcus epidermidis (S. epidermidis), with three strains resistant to all classes of antibiotics recently emerging.
The team tested whether this bacterium, commonly found on human skin, responded to electrical stimulation – also known as selective excitability.
Outside of the body S. epidermidis is generally harmless and can even protect the skin against pathogens, but if it enters the body through a cut or medical procedure then it can cause serious infections.
First author Saehyun Kim, from the University of Chicago, said bacteria’s response to electricity was not well explored, partially because it was not known the specific conditions under which bacteria “will be excited.”
“Discovering this selective excitability will help us discover how to control other bacteria species by looking at different conditions,” the researcher said.
The team stimulated the bacteria using 1.5 volts of electricity – well below the 15 volts deemed safe for human use – for 10 seconds, every 10 minutes, for 18 hours.
They found that in acidic environments the electric shocks stopped 99% of biofilm – a cluster of bacteria that blocks drugs and leads to persistent infection.
But the electric shocks had no effect on the bacteria in pH neutral conditions.
While the results were promising, the skin around chronic wounds is generally not acidic compared to healthy human skin which is mildly acidic.
To effectively treat wounds with electricity the team created a skin patch that contains electrodes and a hydrogel to create an acidic environment.
Testing showed the Bioelectronic Localized Antimicrobial Stimulation Therapy, or BLAST, patch resulted in 10 times less S. epidermidis after 18 hours when tested on pork skin compared to an untreated sample. The same results were seen when it was tested on a catheter.
Co-senior author Bozhi Tian, also from the University of Chicago, said it opened up exciting possibilities for drug-free treatments, especially for skin infections and wound healing, where antibiotic-resistant bacteria posed a serious challenge.
He said that with further research to examine the safety and effectiveness of this treatment, scientists could develop a wearable patch with a wireless circuit to control infections without drugs.