Researchers in N.S. develop family of antibiotics to combat superbugs

Researchers in Nova Scotia led by Dalhousie University's Christopher McMaster have developed new treatments for superbugs — bacteria that no longer respond to current medications.

His team discovered 30 effective antibiotics after a decade of research and experimenting with over 700 variations. 

McMaster said the excessive use of antibiotics has resulted in some medicines becoming ineffective in treating infections. 

"We were able to come up with a family of 30 different molecules that all inhibit the same enzyme," he said.

"Some are really good to be delivered topically, some you can take orally, some you can put through an IV. And they all work against all the drug-resistant bugs that are out there."

According to the World Health Organization, superbugs are a global threat to public health and development. They are responsible for more than five million deaths, the organization says.

Paul Bonnar, an infectious disease physician with Nova Scotia Health, said many common infections are treated with oral antibiotics in the form of pills. 

However, he said it is becoming more common to find cases where that medicine is ineffective, so doctors need to use a stronger antibiotic delivered through an IV. 

Bonnar said that "stresses the whole health-care system" because patients then need to come directly to the hospital. 

But even then, some superbugs can resist that. 

"Currently, we have some patients that even most intravenous antibiotics don't work anymore," he said. "So we're really stuck using third or fourth-line agents that are expensive and have side-effects associated with them," he said. 

Effective on diabetic foot ulcers infections

McMaster said some of these new antibiotics are especially effective against diabetic foot infections. 

People with diabetes often struggle with poor circulation, says McMaster, meaning their body cannot transport medicine and immune cells to where the infection is. 

Even when medicine does reach the infection, superbugs make it hard to treat. 

According to Diabetes Canada, these infections are the leading cause of amputations, causing 70 per cent of amputations at hospitals. 

McMaster added this is a significant risk factor for mortality in patients with diabetes. 

Next steps

McMaster said the lab tests have been successfully peer-reviewed and the team is now looking for funding to move to safety and toxicity trials. 

Sam Ruttonsha, director of DeNovaMed Inc., said the next step to ensure the drug is effective in humans will cost around $8 million.