FIGURE 1.

Synovial fluid aggregate morphology and composition. (A) (Top) Using SEM, biofilm morphology in samples retrieved from an infected knee replacement [periprosthetic joint infection (PJI)] or formed on titanium using methicillin-susceptible Staphylococcus aureus (MSSA) in human synovial fluid (SynF) or Trypticase Soy Broth (TSB). (Bottom) Floating aggregates retrieved from an infected knee replacement or floating aggregates formed with MSSA in human synovial fluid. (B) Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) gel stained with Coomassie Blue. The gel shows the composition of human synovial fluid and of synovial fluid MSSA aggregates from three separate samples of synovial fluid, as compared to fibronectin (Fn), fibrinogen (Fg), albumin (Alb), and serum controls. (C) Western blot analysis of MSSA aggregates from synovial fluid for Alb (left) and for Fg (right). The γ−γ dimer and α chain are indicated, as compared with human synovial fluid, Fg, and Alb standards. Lanes represent human synovial fluid samples and resulting aggregates from different samples. (D) MSSA aggregates stained for Alb, Fg, or secondary antibody alone (Control). All images are representative images of at least three samples.