FIG 2.

(A) Biofilm formation measured by the clinical BioFilm Ring Test (cBRT) for MRSA strains. Clinical isolates were classified as weak biofilm producers (WBP) and strong biofilm producers (SBP). All results were expressed as a percentage of strains with the specific biofilm-forming ability. (B) Resazurin conversion into resorufin measured after 20 h of incubation, for WBP and SBP. ***, P < 0.001, using the Mann-Whitney test for the absorbance values after 1,200 min. Data represent means and the standard errors of two independent experiments analyzed in duplicate. (C) Representative Apotome microscopy images of WBP (left panel) and SBP (right panel) MRSA biofilms, stained with the Live/Dead BacLight bacterial viability kit and analyzed with ZEN 3.1 software, after 20 h of incubation at 37°C. Orthogonal sections displaying horizontal (z) and side views (x and y) of reconstructed 3-dimensional (3D) biofilm images are shown.