Microplastic pollution in the body could be fueling bacteria and viruses’ ability to withstand the effects of antibiotics, researchers have said.
Researchers at Boston University said Tuesday that they were “shocked” to see that bacteria’s antimicrobial resistance is strengthened when exposed to the tiny plastic particles.
“The plastics provide a surface that the bacteria attach to and colonize,” Neila Gross, a Ph.D. candidate at the university, explained in a statement announcing the “startling discovery.”
The findings help to shed some light on a major issue for medical professionals. In 2019, bacterial antimicrobial resistance was directly responsible for 1.27 million deaths and it contributed to nearly 5 million deaths around the world, according to the World Health Organization. In the U.S., more than 35,000 people die each year as a result of antimicrobial-resistant infections, according to the Centers for Disease Control and Prevention.
It comes with significant economic costs, with estimates from the World Bank projecting that antimicrobial resistance could result in $1 trillion in additional healthcare costs over the course of the next 25 years.
Of course, microplastics come with their own health costs, although the full extent of their impact on the human body is not totally clear. Recent studies have shown they’re in our hearts, brains, and even our genitals. They’ve been linked to an increased risk of heart disease and could be tied to dementia. The minuscule particles are now understood to be pervasive throughout Earth’s environment, and humans are exposed through animal products, plastic ware, water and even air.
When bacteria, viruses, parasites and fungi mutate over time, they can stop responding to medicines, making infections harder to treat and increasing the risk of disease spread and death. The misuse and overuse of antimicrobials against those invaders are the main drivers in the development of drug-resistant organisms that cause disease.
The World Health Organization says humanity faces what it calls an “antibiotics pipeline and access crisis,” given inadequate research and development in the face of rising levels of resistance.
Antimicrobial resistance also disproportionately impacts low- and middle-income countries, with its drivers and consequences exacerbated by poverty and inequality.
“Historically, people have associated antibiotic resistance with patient behavior, like not taking antibiotics as prescribed. But there is nothing a person has done to be forced to live in a particular environment, and the fact is they are at a higher exposure to resistant infections,” noted Muhammad Zaman, a Boston University College of Engineering professor of biomedical engineering.
To reach these conclusions, the Zaman Laboratory tested how E. coli — a culprit known to contribute to foodborne illness — reacted to being in a closed environment with microplastics. When attached to any surface, bacteria create a sticky substance that serves as a shield, protecting itself and keeping it securely attached to the surface. In testing, researchers saw the microplastic they used supercharged the shield so much that antibiotics were unable to get through.
“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. “It was staggering to see.”
Gross is the lead author of the research that was published in the journal Applied and Environmental Microbiology.
Researchers performed the experiment multiple times, but the results remained consistent: bacteria exposed to microplastics became resistant to multiple types of antibiotics commonly used to treat infections.
“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 said.
The next step is to understand how these findings translate to the outside world, and to determine the mechanisms that allow bacteria to grip plastic. Although, the authors noted that it’s possible plastics that start to take in moisture over time absorb antibiotics before they reach the target bacteria.
Much more research needs to be done to understand microplastics, as well.
Ultimately, the WHO says there’s an urgent need for additional measures to ensure equitable access to new and existing vaccines and other medicine.
“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,” said Zaman.
