Research Puts a Charge into Fight Against Bacteria

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Bug-zappers aren’t just for mosquitoes. A new University of Guelph study might ultimately help doctors widen the use of electrotherapy for fighting infectious bacteria that prevent wounds from healing.

Managing chronic wounds costs the Canadian health-care system about $4 billion a year, said engineering professor Suresh Neethirajan: “We would like to bring down those costs.”

Along with master’s student Eric Birkenhauer, he used nanotech tools to show how electrical charges can keep potentially deadly pathogens from attaching to surface materials used in many medical devices.

Their study was published this week in the Royal Society of Chemistry’s Advances journal.

The researchers also found that growing different bacterial species together can change electrical properties on their cell surfaces and affect how they attach to materials.

Unlike acute infections, chronic wounds may last for months or years, particularly in people with diabetes, cancer or other diseases.

The Guelph researchers want to help prevent infectious bacteria from sticking to wounds and medical equipment from needles to surgical implants.

They used an atomic force microscope to study and alter surface charges on bacteria and stainless steel, and to observe interactions between methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa.

Both species can rapidly form biofilms that delay or prevent wound healing, and both are potentially deadly for patients with compromised immune systems, said Birkenhauer.

Adhesion is the first – and only reversible – step used by bacteria to make protective biofilms. Left untreated, biofilm contamination may cause sepsis and even death.

Bacteria use different mechanisms to attach to surfaces, including electrical surface charges. Emerging therapies such as electrical stimulation or nano-coatings might help doctors get around antimicrobial resistance that makes drug-resistant strains of bacteria ever harder to treat.

“Electrical stimulation is now being considered as a potential therapeutic treatment for wound healing and as a preventive measure for microbial attachment and biofilm formation,” said the paper.

Besides medical applications, Neethirajan said, their work might also be used to help prevent bacteria from building up in pipelines and in industrial equipment.

The researchers plan to look at other surface coatings, including non-conductive surfaces, and at how cells behave in electrical fields.