Microplastics may be stoking antibiotic resistance: Study

Yahoo

11-03-2025

The microscopic shards of plastic found in every corner of the planet may be exacerbating antibiotic resistance, a new study has found.
Bacteria exposed to these ubiquitous fragments, known as 'microplastics,' became resistant to multiple types of antibiotics commonly used to treat infections, researchers showed in the study, published on Tuesday in Applied and Environmental Microbiology.
The authors expressed alarm about their discovery, particularly for people living in high-density, low-income places like refugee settlements, where plastic piles up and bacterial infections spread with ease.
'The fact that there are microplastics all around us, and even more so in impoverished places where sanitation may be limited, is a striking part of this observation,' said senior author Muhammad Zaman, a professor of biomedical engineering at Boston University, in a statement.
The possibly greater risk among residents of disadvantaged communities 'underscores the need for more vigilance' and research into microplastic and bacterial interactions, Zaman added.
About 4.95 million people worldwide die from antimicrobial-resistant infections each year, Zaman and his colleagues noted. Meanwhile, they explained bacteria develop resistance not only due to the misuse of medications, but also via the microscopic environments that surround them.
As such, the researchers decided to test how a common bacterium, E. coli, would respond to being in a closed environment with microplastics.
Ultimately, they found that the plastics provided a surface to which the bacteria could attach and colonize, said lead author Neila Gross, a Boston University Ph.D. candidate, in a statement.
Once attached, the bacteria created a biofilm: a sticky material that protects microbes from invaders and keeps them fixed to the surface, Gross explained.
The microplastics, she continued, ended up supercharging the biofilms so much that when the scientists added in antibiotics, the medicine was unable to penetrate the shield.
'We found that the biofilms on microplastics, compared to other surfaces like glass, are much stronger and thicker, like a house with a ton of insulation,' Gross said.
Even when the researchers tested different combinations of antibiotics and types of plastic material, they found that their results were consistent.
'The presence of plastics is doing a whole lot more than just providing a surface for the bacteria to stick — they are actually leading to the development of resistant organisms,' Zaman added.
Going forward, the researchers said they plan to determine whether their findings would apply not just to the laboratory setting, but to the real world as well. For example, they voiced an interest in exploring whether microplastic-related antibiotic resistance is affecting refugee camps overseas.
The authors also expressed their intentions to decipher the precise mechanisms that enable bacteria to maintain such a strong grasp on plastics.
Gross hypothesized that the water-repellant properties of plastics might be allowing bacteria to attach themselves, but that over time, the materials could be taking in moisture and absorbing the antibiotics before they could reach the bacteria.
Regardless of the way this resistance develops, Zaman focused on the notion that microplastic prevalence might be further endangering already underfunded health systems that serve refugee populations.
'Too often, these issues are viewed from a lens of politics or international relations or immigration, and all of those are important, but the story that is often missing is the basic science,' he said. 'We hope that this paper can get more scientists, engineers, and more researchers to think about these questions.'
Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.