Thursday, October 2, 2025
Antibiotic resistance is often called the “silent pandemic,” a growing global threat that makes bacterial, viral, and fungal infections harder to treat, increasing the risk of severe illness or death.
But what if the roots of this problem aren’t only in healthcare settings? What if the answers to what helps drive antimicrobial resistance could be found outside the doors of the hospital, in the environment, even in the wastewater flowing beneath our cities and communities?
Dr. Gustavo Ybazeta, a genomicist and microbiology researcher at HSNRI, is tackling this question head-on. His latest project, funded through a national Natural Sciences and Engineering Research Council (NSERC) Discovery Grant, is examining how exposure to heavy metals such as copper, lead, and mercury affects the ways bacteria are developing resistance to antibiotics by sampling wastewater from treatment plants across Northern Ontario. Collaborators on this project are the city treatment plant of Sudbury and the public health unit. Also, Dr Aleksandra Mloszewski is a research scientist at the Geological Survey of Canada. Our team in the laboratory are Dr. James Knockleby and Barbara Barbosa Langella. She also received the 2025 Canada Graduate Scholarships Master’s competition to work on this project.
“This isn’t something most people think about,” said Dr. Ybazeta. “When we talk about antimicrobial resistance, people picture overuse of antibiotics in humans or animals. But bacteria are under pressure from other environmental factors, too. In Northern Ontario, with its long mining history, heavy metals are part of that story.”
Similar to humans evolving to resist certain infections, bacteria can evolve to resist antibiotics to survive the treatments that once killed them, said Dr. Ybazeta. This is called antimicrobial resistance (AMR). What’s less known is that bacteria can also resist toxic metals, like lead, copper, or mercury, and these metals can have a surprising role in influencing AMR. Many bacteria carry both metal resistance genes (MRGs) and antibiotic resistance genes (ARGs), and they can swap these genetic traits like passing notes in class. When heavy metals linger in water or soil, they create conditions where bacteria with both types of resistance genes thrive — and spread their survival skills.
“Think of it applying pressure to one end of a scale, affecting the balance” said Dr. Ybazeta. “If bacteria can survive in a metal-contaminated environment, they have an advantage. If those same bacteria also resist antibiotics, that advantage becomes even bigger. Over time, these genes become widespread in the microbial community, making it more challenging to treat bacterial infections.”
The research is rooted in local realities. Northern Ontario is home to a large mining industry and numerous wastewater treatment plants serving both urban and rural communities. Metals and other pollutants from industrial and natural sources often end up in wastewater, making the region an ideal case study for how environmental factors influence resistance.
The project is asking key questions:
• How do heavy metals and pollutants in wastewater affect the sharing of resistance genes?
• Do different treatment plants create unique conditions that speed or slow this process?
• Can these changes be tracked to predict future resistance hotspots?
To find answers, Dr. Ybazeta’s team is collecting wastewater samples from treatment plants across the region. They’ll analyze the heavy metal composition and bacterial genetics in each sample, building a detailed picture of how resistance spreads under different environmental conditions.
The ultimate goal is ambitious but critical: predictive models that help local communities and environmental agencies act before resistance spirals out of control.
“This research gives us the power to anticipate,” said Dr. Ybazeta. “If we can identify patterns, for example, when a certain level of metal contamination correlates with a spike in resistance genes, we can intervene early. That might mean changes in how we treat wastewater, manage industrial runoff, or even design hospital antibiotic management programs.”
For Dr. Ybazeta, he said the implications extend far beyond academic interest.
“The same water that leaves a treatment plant eventually connects with rivers, lakes, and communities,” he said. “If resistant bacteria are spreading through these systems, it’s not just an environmental problem; it’s a public health problem. This research will ultimately help to protect vulnerable populations and reduce the burden of hard-to-treat infections in clinical settings.”
Experts warn that if antimicrobial resistance continues unchecked, it could claim millions of lives globally by 2050, he said.
“This isn’t a distant issue,” said Dr. Ybazeta. “It’s here, it’s local, and understanding the environmental side of the equation is key to stopping it.”
As samples come in and data begins to take shape, the hope is clear: by unraveling the hidden connections between metals, microbes, and medicine, Sudbury researchers could help lead the fight against one of the most urgent health threats of our time.