Researchers at Boston University have discovered that microplastics may accelerate the development of antibiotic-resistant bacteria. This finding has major implications, particularly for vulnerable populations living in high-density, impoverished areas.
Microplastics — tiny shards of plastic debris — pervade our planet. They infiltrate food chains, accumulate in oceans, gather in clouds and on mountains, and even find their way inside our bodies at alarming rates. As scientists race to uncover the consequences of such widespread plastic contamination, a team from Boston University (BU) has made a startling discovery: microplastics could be fueling the rise of drug-resistant bacteria.
According to the researchers, bacteria exposed to microplastics become resistant to multiple types of antibiotics commonly used to treat infections. This is especially concerning for people in high-density, impoverished areas such as refugee settlements, where discarded plastic piles up and bacterial infections spread easily.
The study was recently published in Applied and Environmental Microbiology.
“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,” Muhammad Zaman, a BU professor of biomedical engineering who studies antimicrobial resistance and refugee health, said in a news release. “There is certainly a concern that this could present a higher risk in communities that are disadvantaged, and only underscores the need for more vigilance and a deeper insight into [microplastic and bacterial] interactions.”
Antimicrobial-resistant infections are a growing global health hazard, responsible for an estimated 4.95 million deaths each year. While misuse and overprescribing of antibiotics are well-known factors, the microenvironment — the immediate surroundings of a microbe — also plays a pivotal role.
In Zaman’s laboratory at BU, researchers rigorously tested how Escherichia coli (E. coli) reacted when exposed to microplastics in a closed environment.
“The plastics provide a surface that the bacteria attach to and colonize,” added lead author Neila Gross, a BU doctoral candidate in materials science and engineering.
Once attached to any surface, bacteria create biofilms — a sticky substance that acts like a shield, protecting them from antibiotics and environmental threats.
Gross noted that microplastics significantly intensified these biofilms, making them far tougher and impervious to antibiotics.
“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 added.
The resilience of these biofilms when exposed to antibiotics was so remarkable that Gross repeated her experiments multiple times with various combinations of antibiotics and plastic materials — all yielding consistent results.
“We’re demonstrating that 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.
This finding is particularly relevant to refugees and forcibly displaced populations, who are already at a higher risk of contracting drug-resistant infections due to overcrowding and limited access to health care.
As of 2024, approximately 122 million people worldwide were displaced. According to Zaman, the prevalence of microplastics could be adding another layer of risk to already stressed health systems in refugee camps.
Gross and Zaman plan to extend their research to real-world environments and hope to partner with international researchers to monitor refugee camps for microplastic-related antibiotic-resistant bacteria and viruses. They also aim to uncover the precise mechanisms that enable bacteria to form potent biofilms on plastic surfaces.
“Plastics are highly adaptable,” Gross added.
Their molecular composition might facilitate bacterial growth, but the exact process remains unclear. One theory suggests that plastics’ hydrophobic nature enables bacteria to easily attach, absorbing antibiotics before reaching the bacteria. Remarkably, the bacteria retained their biofilm-forming capability even after the microplastics were removed.
“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,” Zaman concludeds. “We hope that this paper can get more scientists, engineers and more researchers to think about these questions.”
Source: Boston University