Biofilm formation by bacteria that colonize biomedical implants cause infections that cannot be eradicated by antibiotic therapy. Bacteria in biofilms are tolerant to every antibiotic known today, and this tolerance is partly due to their low metabolic activity, the occurrence of persister cells, and to the protective properties of the biofilm matrix. Strategies for combatting these troublesome infections often fall in to one of two categories: Biomaterial development aimed at preventing biofilm formation, or development of novel drug formulations that more effectively reach their target and kill the bacteria in biofilms.
Innovative biomaterials may at best delay biofilm formation and an important question in this context is to understand how the material can contribute to more successful antibiotic treatment by not providing the cues that trigger the onset of antibiotic tolerance in the attached bacteria. This is an aspect we are currently studying in the development of anti-adhesive polymer coatings.
While novel biomaterials may lower the risk of acute infections shortly after surgery, it is unlikely that such infections can be prevented indefinitely. It is therefore also important to work towards developing treatments that more effectively tackle biofilm infections. We have explored how the combination of antibiotic therapy with matrix-targeting enzymes can enhance the efficacy of antibiotics. The matrix composition is highly variable among different bacterial species, and this strategy will not produce a one-fits-all solution. However, for Staphylococcus aureus biofilms, we have found a promising lead in targeting the matrix with fibrinolytic drugs, and we are now moving on to test our treatment strategy in vivo.