Plastic pollution may be fuelling one of the world’s greatest health threats responsible for millions of global deaths each year, scientists have warned. The tiny shards of plastic debris are thought to aid the development of antimicrobial resistance, which leads to common antibiotics becoming ineffective against infections.
A study found that microplastics can provide a suitable surface for bacterials to attach to and colonise, forming a biofilm — a sticky substance that acts like a shield. Laboratory tests with E.coli showed microplastics “supercharged” the bacterial biofilms so much that when antibiotics were added to the mix, the medicine was unable to penetrate the shield.
Lead researcher Neila Gross, of Boston University, said: “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. It was staggering to see.”
It is not entirely clear how plastic helps bacteria flourish, Ms Gross said. One theory is that plastics repel water and other liquids, allowing bacteria to easily attach themselves. But over time, the plastics start to take in moisture and may absorb antibiotics before they reach the target bacteria.
The research also found that even when the microplastics were removed from the equation, the bacteria they once housed kept the ability to form stronger biofilms.
Professor Muhammad Zaman, an expert in biomedical engineering and migrant health at Boston University, said: “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.”
Antimicrobial resistance has been linked to almost five million deaths per year.
Previous research has found that refugees, asylum seekers and displaced populations are more likely to contract drug-resistant infections due to living in overcrowded camps with limited healthcare.
Prof Zaman added: “Historically, people have associated antibiotic resistance with patient behaviour, 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.”
The findings were published in the journal Applied and Environmental Microbiology.