Researchers Unearth Powerful New Antibiotic from Soil

Nearly three decades after the last novel class of antibiotics reached the market, researchers at McMaster University have uncovered a potential game-changer in the fight against antimicrobial resistance.

Led by Professor Gerry Wright, a team of scientists has identified a new class of antibiotics—lariocidin—that shows strong promise against some of the world’s most drug-resistant bacteria. The findings were published in the journal Nature.

This discovery comes at a critical time. As bacteria continue to evolve resistance to existing treatments, the demand for new antimicrobial agents has become urgent. Antimicrobial resistance (AMR) is widely recognized as one of the most pressing public health threats globally.

“Our old drugs are becoming less and less effective as bacteria become more and more resistant to them,” said Wright. “About 4.5 million people die every year due to antibiotic-resistant infections, and it’s only getting worse.”

Wright is a professor in the Department of Biochemistry and Biomedical Sciences and a researcher at the Michael G. DeGroote Institute for Infectious Disease Research.

What Makes Lariocidin Unique?

The newly discovered molecule, a type of lasso peptide, interacts directly with bacterial protein synthesis machinery. Unlike existing antibiotics, its mode of action is distinct, making it particularly effective at inhibiting bacterial growth and survival.

“This is a new molecule with a new mode of action,” Wright explained. “It’s a big leap forward for us.”

Even more striking: the bacteria that produce lariocidin were isolated from a simple backyard soil sample in Hamilton. The team spent about a year cultivating these soil microbes in the lab, which gave them time to detect even slow-growing species that might typically go unnoticed.

One of these—Paenibacillus—produced a novel substance that demonstrated potent activity against other bacteria, including strains typically resistant to treatment.

“When we figured out how this new molecule kills other bacteria, it was a breakthrough moment,” said Manoj Jangra, a postdoctoral fellow on the team.

Beyond Discovery: Safety and Next Steps

In addition to its novel mechanism and potency, lariocidin ticks several crucial boxes for therapeutic potential: it’s non-toxic to human cells, bypasses known resistance mechanisms, and has already shown efficacy in animal infection models.

But there’s still work to do. Wright’s team is now focused on modifying the molecule and scaling up production to move it closer to clinical development.

“Since this molecule comes from bacteria—and bacteria aren’t exactly trying to make medicine for us—we’ll need more time and resources to turn it into a drug,” Wright noted.

“The initial discovery—that big A-ha! moment—was astounding for us. But now the real hard work begins. We’re taking this molecule apart and putting it back together to make it a better drug candidate.”