Washington | Scientists have successfully used a mild electric current to kill drug-resistant bacterial infections, a technology that may eventually be used to treat chronic and serious wound infections.
Researchers at Washington State University (WSU) in the US used an antibiotic in combination with the electric current to kill all of the highly persistent Pseudomonas aeruginosa PAO1 bacteria in their samples.
The bacteria is responsible for chronic and serious infections in people with lung diseases, such as cystic fibrosis, and in chronic wounds.
It also often causes pneumonia for people who are on ventilators and infections in burn victims.
“Killing most of the persister cells was unexpected. Then we replicated it many, many times,” said Haluk Beyenal, Professor at WSU.
Bacterial resistance is a growing problem around the world. While antibiotics were a miracle drug of the 20th century, their widespread use has led to drug-resistant strains.
When doctors use antibiotics to treat a bacterial infection, many of the bacteria die. Bacteria that form a slime layer (called a biofilm), however, are more difficult to kill because antibiotics only partially penetrate this protective layer.
Sub-populations of “persister” cells survive treatment and are able to grow and multiply, resulting in chronic infections.
The researchers used an “e-scaffold,” a sort of electronic band-aid made out of conductive carbon fabric, along with an antibiotic to specifically tackle these persister cells.
The e-scaffold creates an electrical current that produces a low and constant concentration of hydrogen peroxide, an effective disinfectant, at the e-scaffold surface.
The hydrogen peroxide disrupts the biofilm matrix, damages the bacterial cell walls and DNA, allowing better antibiotic penetration and efficacy against the bacteria.
“It turns out the hydrogen peroxide is really hard on biofilms,” said Doug Call, a professor in the Paul Allen School of Global Animal Health.
Researchers have tried electrical stimulation as a method to kill bacteria for more than a century but with only mixed results. Beyenal’s team determined the conditions necessary for the electrochemical reaction to produce hydrogen peroxide.
The current has to be carefully controlled, however, to assure the correct reaction at an exact rate. Their method also does not damage surrounding tissue, and the bacteria are unable to develop resistance to such an electrochemical treatment.
The researchers have filed a patent application and are working to commercialise the process.
The research was published in the journal ‘npj Biofilms and Microbiomes’.
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