Importantly, when Staphylococcus aureus was introduced into joint fluid, the bacteria was still able to colonize model implant surfaces, i.e. titanium pins, and form biofilms. The persistence of these bacteria in synovial fluid containing antibiotics may be one reason that joint infection is so difficult to cure.
The team's previous research identified these floating biofilm-like clumps of bacteria as a source of antibiotic-resistant joint infections. These biofilm-like clumps arise because bacteria embed themselves in a protective mesh of proteins that resist the penetration of antibiotics. They also found that the bacteria slow their growth, making them even less susceptible to antibiotics, which are designed to target rapidly growing cells like bacteria.
"The next step is to see how we can disperse these mega-clusters of buried bacteria. If we can provide a window for antibiotics to carry out their intended function, we can move towards a clinical model and ultimately cure joint infection," offered Sana Dastgheyb, Ph.D., lead author on this study and researcher at both Thomas Jefferson University and the National Institutes of Health.