A superbug commonly found in hospitals has developed the ability to digest certain medical plastics, including those used in sutures, stents, and implants.
This alarming discovery means many plastic-based medical tools could be more vulnerable than previously thought, raising urgent questions about hospital infection control and material design.
Superbug Devours Medical Plastics
A dangerous hospital superbug has just added something unexpected to its menu: plastic. And not just any plastic -- this one is used in medical implants, surgical stitches, and wound dressings inside the human body.
In a breakthrough study, microbiologists at Brunel University London discovered that Pseudomonas aeruginosa, a common and sometimes deadly hospital-acquired infection, can actually "feed" on medical plastic to stay alive. This ability could help it survive longer in hospital environments -- and even inside patients.
The study, published in Cell Reports, is the first to show that this type of bacteria can break down polycaprolactone (PCL), a biodegradable plastic found in items like stents, surgical mesh, drug-delivery patches, and sutures. This challenges the long-standing belief that medical plastics are immune to microbial attack.
Medical Devices at Risk
"It means we need to reconsider how pathogens exist in the hospital environment," said Professor Ronan McCarthy, who led the study. "Plastics, including plastic surfaces, could potentially be food for these bacteria. Pathogens with this ability could survive for longer in the hospital environment. It also means that any medical device or treatment that contains plastic could be susceptible to degradation by bacteria."
The researchers didn't just observe the bacteria's appetite -- they pinpointed the exact enzyme doing the damage. Called Pap1, this enzyme was isolated from a strain of Pseudomonas aeruginosa taken from a patient's wound. In lab tests, it degraded nearly 80% of a plastic sample in just one week. Even more shocking? The bacteria used the plastic as its only source of energy -- essentially "eating" it to stay alive.
Boosting Bacterial Defenses
This plastic-digesting power also makes the bug more dangerous. The team showed that the broken-down plastic fragments helped it form tougher biofilms -- the protective clingy bacterial coatings that help bacteria overcome antibiotics and make infections harder to treat.
Pseudomonas aeruginosa is among a group of bacteria responsible for the majority of hospital infections that can resist antibiotics. It is listed on the World Health Organization's critical priority list for new treatments and is a major cause of catheter-related Urinary Tract Infections and ventilator-associated pneumonia -- both of which involve plastic-based medical equipment.
Wider Plastic Vulnerability
The implications stretch beyond one material. While the team confirmed degradation only for PCL, they identified signs of similar enzymes in other pathogens. This means that other plastics could also be vulnerable to microbial attack -- and some of the most widely used medical materials made from polyethylene terephthalate or polyurethane may be at risk.
The bug's plastic-eating ability is likely helping it survive on surfaces in hospitals, potentially driving hospital outbreaks. McCarthy said that we should start to consider focusing on plastics that are harder for microbes to digest and potentially screening pathogens for these enzymes, especially in unexplained prolonged outbreaks. Infection control experts may also need to rethink how they monitor hospital environments. He did highlight that this was one study and that more research is now urgently needed to learn more about how prevalent these enzymes are amongst pathogens and the impacts that they can have on virulence.
"Plastic is everywhere in modern medicine, and it turns out some pathogens have adapted to degrade it," said McCarthy, "and we need to understand the impact this has on patient safety."
Reference: "Pseudomonas aeruginosa clinical isolates can encode plastic-degrading enzymes that allow survival on plastic and augment biofilm formation" by Sophie A. Howard, Rubén de Dios, Evgenia Maslova, Antonis Myridakis, Thomas H. Miller and Ronan R. McCarthy, 7 May 2025, Cell Reports.
DOI: 10.1016/j.celrep.2025.115650