Fig 2. Variable biofilm production among endophthalmitis isolates.

In vitro biofilm production of 15 E. faecalis endophthalmitis isolates. Biofilm formation was measured as the optical density (OD) at 550nm using a standard crystal violet-based assay. Isolates are arranged according to their sequence type (ST), and STs with more than one isolate are labeled. Bars shown mean crystal violet absorbance values, and error bars show standard deviation of triplicate experiments, each with eight technical replicates. NC = negative control; ****P<0.0001 by two-tailed t test; ns = not significant.