Medial plastic-consuming 'superbug' discovered
In a groundbreaking discovery, researchers have found that certain bacteria common in hospital environments, such as Pseudomonas aeruginosa, can degrade medical plastics used in devices like sutures, stents, implants, and wound dressings. This bacterium produces a unique enzyme called Pap1 that breaks down polycaprolactone (PCL), a biodegradable plastic widely used in medical applications.
By degrading PCL, the bacteria not only survive on these medical plastics by converting fragments into usable nutrients, but they also enhance biofilm formation on the device surfaces. These biofilms protect bacteria against antibiotics and the immune system, making infections harder to treat.
The implications for hospital-acquired infections (HAIs) are significant. Since these bacteria can persist and strengthen their colonies on medical devices by feeding on the plastics themselves, there is a heightened risk of chronic, antibiotic-resistant infections associated with implanted devices and surgical materials. This finding challenges the assumption that medical plastics are inert and sterile surfaces, prompting a need to reconsider the design, monitoring, and sanitation protocols related to plastic medical devices to better prevent infections in clinical settings.
Moreover, similar enzymes have been found in other hospital pathogens, indicating a broader vulnerability of different plastics (beyond PCL) used in hospitals. This could further complicate infection control and patient safety.
Pseudomonas aeruginosa is among a group of bacteria responsible for the majority of hospital infections that can resist antibiotics. Some widely used medical materials made from polyethylene terephthalate or polyurethane may also be at risk.
The plastic the bacteria can digest is specifically PCL, which is used in various medical devices such as bone scaffolds, dental implants, bandages, wound dressings, catheters, and breast implants. The bacterial enzyme Pap1, isolated from a strain of Pseudomonas aeruginosa, can degrade 78% of a plastic sample in just seven days.
The impact of pathogens digesting medical plastics on patient safety needs further understanding. Infection control experts may need to rethink hospital environment monitoring, and screening pathogens for enzymes that digest plastics may be necessary in unexplained prolonged outbreaks.
The discovery of plastic-eating enzymes in pathogens suggests other plastics could also be vulnerable to microbial attack. More research is needed to understand the prevalence and impacts of these enzymes on pathogens and virulence. To mitigate the risks, experts suggest focusing on plastics harder for microbes to digest.
Pseudomonas aeruginosa is listed on the World Health Organisation's critical priority list for new treatments. The plastic-digesting ability of this bacterium makes it more dangerous, as it helps form tougher biofilms, protective bacterial coatings that help bacteria overcome antibiotics and make infections harder to treat. The implications of this discovery stretch beyond one material, as similar enzymes have been identified in other pathogens, suggesting that other plastics could also be vulnerable to microbial attack.
- The bacteria found in hospital environments, such as Pseudomonas aeruginosa, have the ability to digest medical plastics like polycaprolactone (PCL), which are used in various health-and-wellness devices such as bone scaffolds, dental implants, and wound dressings.
- The digital health sector should focus on developing plastics that are harder for bacteria to degrade, as the recent discovery of plastic-eating enzymes in pathogens like Pseudomonas aeruginosa has shown that traditional medical plastics can be susceptible to microbial attack, potentially leading to more severe medical-conditions associated with infections in hospital settings.
