Superbug infections often do not respond to common antibiotics, resulting in prolonged illness and higher risk of death.
The team, from McMaster University in Hamilton, ON, and The Scripps Research Institute, La Jolla, CA, report their findings in the open access journal eLife.
The World Health Organization have declared antibiotic resistance a major threat to global health and that without effective antimicrobial drugs, many standard medical treatments will fail or turn into very high-risk procedures.
Infections caused by drug-resistant microbes, or "superbugs," often fail to respond to commonly used antibiotics, resulting in prolonged illness, higher medical costs and greater risk of death.
For example, the UN health agency estimates that people infected with the drug-resistant bacterium MRSA (methicillin-resistant Staphylococcus aureus), are 64% more likely to die than people with a non-resistant form of the infection.
In the US, at least 2 million people develop superbug infections, and at least 23,000 people die each year as a direct result of them, say the Centers for Disease Control and Prevention (CDC).
Drug stops assembly of protein-making machinery in bacteria
Most antibiotics target a vital process in bacteria - for example, to stop them replicating or making essential proteins.
In this new study, the team found that an old drug called lamotrigine can prevent bacteria from being able to assemble ribosomes, the machinery that bacteria use to make proteins.
Lamotrigine, marketed in most of the world as Lamictal (by GlaxoSmithKline), is an anticonvulsant drug, also effective as a mood stabilizer, that is used in the treatment of epilepsy and bipolar disorder.
The study is the first to show that a drug can inhibit the assembly of ribosomes in bacteria. Many antibiotics are effective because they attack what ribosomes do, but this is the first demonstration of a drug being able to prevent the ribosomes being created in the first place.
New class of antibiotics
Principal investigator Eric Brown, a professor of biochemistry and biomedical sciences at McMaster's, says:
"Such molecules would be an entirely new class of antibiotics, which would get around antibiotic resistance of many bacteria. We found lamotrigine works," he adds.
"Ribosome-inhibiting antibiotics have been routinely used for more than 50 years to treat bacterial infections, but inhibitors of bacterial ribosome assembly have waited to be discovered."
In their paper, the researchers also describe how they identified the exact place in the bacterial cell that the drug targets. This helped them better understand how ribosomes assemble and the biochemistry of how to attack the process with drugs.
Meanwhile, Medical News Today recently learned how researchers in Sweden discovered honeybees contain bacteria with strong antimicrobial properties - including the ability to fight MRSA.