Antibiotics are one of the greatest breakthroughs in medicine, saving millions of lives from bacterial infections until antimicrobial resistance took a toll. Reportedly, antibiotics’ effectiveness is under threat, as evidenced by the World Health Organization, which has labeled antimicrobial resistance as one of the top global health threats.
A new study has found that bacteria exposed to microplastics became resistant to multiple types of antibiotics commonly used to treat infections. An indication that antimicrobial resistance could soon hit the roof if contamination and pollution continue.
According to WHO, there are 4.95 million deaths associated with antimicrobial-resistant infections each year. Traditionally, the resistance has been associated with misuse and prescription of medications. However, the study by Boston University found that a huge factor that fuels resistance is the microenvironment, the immediate surroundings of a microbe where bacteria and viruses replicate.
Microplastics, tiny shards of plastic debris, contribute to the crisis by providing a perfect breeding ground for bacteria by helping them form stronger biofilms.
“The plastics provide a surface that the bacteria attach to and colonize,” says Neila Gross (ENG’27), a BU PhD candidate in materials science and engineering and lead author of the study. Once attached to any surface, bacteria create a biofilm, a sticky substance that acts like a shield, protecting the bacteria from invaders and keeping them affixed securely.
Even though bacteria can grow biofilms on any surface, Gross observed that the microplastic supercharged the bacterial biofilms so much that when antibiotics were added to the mix, the medicine was unable to penetrate the shield.
The researchers also 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,” says Gross.
The discovery highlights the precarious future of the healthcare sector as common infections such as urinary tract infections, pneumonia, or post-surgical wound infections that were easily treated could become more resistant to antibiotics.
According to a study by the World Bank, antimicrobial resistance could cost the global economy up to $100 trillion by 2050 if left unchecked. Vulnerable populations, such as those in low-income countries, refugee camps, and overcrowded urban areas, will likely be disproportionately affected.
Despite the threat posed by microplastics, researchers are actively seeking solutions such as biodegradable plastics (plant-based bioplastics and polymer coatings) and alternative materials to reduce global reliance on non-biodegradable plastics.
The adoption of stronger policies to curb plastic pollution is the best global solution. However, the ongoing United Nations negotiations for a global plastics treaty have encountered significant challenges, particularly regarding mandatory limits on plastic production.
During the fifth session of the Intergovernmental Negotiating Committee (INC-5) in Busan, South Korea, no consensus was reached, prompting plans for an additional session in Geneva, Switzerland, from August 5 to 14, 2025, to finalize the treaty.
“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,” says Muhammad Zaman, a Boston University College of Engineering professor of biomedical engineering who studies antimicrobial resistance and refugee and migrant health.
“We hope that this paper can get more scientists, engineers, and more researchers to think about these questions.”
Dr. Tedros Adhanom Ghebreyesus, WHO Director-General, has warned that “antimicrobial resistance is a slow tsunami threatening to undo a century of medical progress. Urgent action is needed to curb its spread, including addressing environmental contributors such as microplastics.“
