A report in Cell Reports shows that a common hospital pathogen can break down and feed on plastics used in medical devices.
Pseudomonas aeruginosa, a bacterium responsible for up to 30 percent of hospital-acquired infections in India, has been found to degrade plastic used in sutures, stents, dressings and implants. Researchers at Brunel University London identified an enzyme, Pap1, in a clinical isolate of P. aeruginosa that breaks down polycaprolactone (PCL), a plastic widely used in medical applications. In laboratory tests, the enzyme degraded 78 percent of a PCL sample within seven days, and the bacteria thrived using plastic as its sole carbon source .
Professor Ronan McCarthy, lead author of the study, said, “It means we need to reconsider how pathogens exist in the hospital environment.” The team isolated Pap1 from a wound sample and showed that when the enzyme was produced in a harmless E. coli strain, clear zones of plastic degradation appeared on PCL-coated agar plates. The native P. aeruginosa strain formed deep pits in plastic beads and reduced their weight by nearly 80 percent in a week. When grown in minimal media with PCL as the only nutrient, the bacterium still showed sustained growth, confirming that it can “eat” the plastic .
Further experiments revealed that the presence of PCL boosted the pathogen’s ability to form biofilms, protective communities that resist antibiotics and immune clearance. Deleting the pap1 gene abolished both plastic degradation and the biofilm increase. In a wax-moth larva infection model, larvae implanted with plastic and then infected with P. aeruginosa had higher mortality, indicating that plastic breakdown products may worsen infections .
The discovery challenges the assumption that medical plastics are inert in the face of pathogens. PCL is valued for its biodegradability and biocompatibility, but its breakdown by P. aeruginosa raises concerns about the integrity of implants and the persistence of bacteria on device surfaces. The study suggests that hospitals should screen for plastic-degrading capacity in outbreak strains and consider adding antimicrobial measures when designing plastic-based medical devices.
With plastic central to medical care, this finding points to a hidden risk: pathogens using our own devices as food. Medical teams and device manufacturers may need to rethink strategies to prevent infection and device failure in the era of plastic-eating superbugs.
