A new study from researchers at Boston University found microplastics may play a role in the spread of drug-resistant bacteria.

The extremely small bits of plastic — known as microplastics and nanoplastics — have become ubiquitous in our environment. Researchers have been unpacking the layers of their impacts.

This recent study published in the journal Applied and Environmental Microbiology found an interaction between microplastics and bacteria that influences the development of antimicrobial resistance.

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It’s already known that small bits of plastic can serve as vehicles for bacterial communities to form, but now we’re learning they can actively drive the development of drug-resistant bacteria.

The researchers found that regardless of the tested size and concentration, the microplastics that were tested facilitated multidrug resistance in four antibiotics (ampicillin, ciprofloxacin, doxycycline and streptomycin) in E. coli within 5 to 10 days of exposure.

“Our findings reveal that microplastics actively drive antimicrobial resistance development in E. coli, even in the absence of antibiotics, with resistance persisting beyond antibiotic and microplastic exposure,” said lead study author Neila Gross, a Ph.D. candidate in the lab of Professor Muhammad Zaman at Boston University. “This challenges the notion that microplastics are merely passive carriers of resistant bacteria and highlights their role as active hotspots for antimicrobial resistance evolution.”

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