Plant Molecule Prevents Formation of Bacterial Biofilms on Catheters and Implants

Biofilms—a slimy bacterial layer that adheres to surfaces—are communities of microorganisms such as bacteria or fungi that stick together and form a protective layer. In medical environments, biofilms pose a challenge because they make infections harder to treat by providing a protective shield for bacteria on devices like catheters and implants. The microbes in biofilms are highly resistant to antibiotics, making treatment difficult. Now, scientists have identified a chemical produced by plants when stressed that prevents biofilm formation on medical implants, thus advancing healthcare.

Bacteria use hair-like structures called fimbriae to anchor themselves to surfaces, a crucial step in biofilm formation. These fimbriae allow bacteria to attach to medical implants, where they create a protective matrix that shields them from antibiotics and cleaning agents. Without fimbriae, biofilm formation cannot begin. Research conducted by scientists at UC Riverside (Riverside, CA, USA) highlights the role of a specific metabolite called MEcPP, which is produced during essential chemical reactions in plants, bacteria, and even some parasites, like the one that causes malaria.

Image: Microscopy images of bacteria strains show one (top) producing fimbriae as normal and one with high level of MEcPP unable to produce the fimbriae (Photo courtesy of Jingzhe Guo/UCR)

The team discovered that MEcPP has a surprising effect on bacteria such as E. coli: it disrupts biofilm formation by interfering with their ability to attach to surfaces. By preventing the initial attachment phase, MEcPP effectively disarms the bacteria’s ability to form biofilms. Through genetic screenings of over 9,000 bacterial mutants, the researchers identified a critical gene called fimE, which acts as an "off switch" for fimbriae production. MEcPP enhances the activity of this gene, leading to increased expression of fimE. As a result, the bacteria are unable to produce fimbriae and cannot form biofilms.

“By preventing the early stages of biofilm development, this molecule offers real potential to improve outcomes in any industries reliant on clean surfaces,” said Katayoon Dehesh, distinguished professor of molecular biochemistry at UCR, and corresponding author of the study published in the journal Nature Communications.