FIGURE 2.

Concentration-dependent effect of linezolid, vancomycin, cloxacillin, rifampicin, and dalbavancin on biofilms in Staphylococcus aureus 240, S. aureus MRSA4, and Staphylococcus epidermidis 43040 strains. (A–C) The antibiotics were added at the beginning of the experiment together with the bacterial inoculum. (D–F) The antibiotics were added when biofilms were already formed, at their exponential growth phase. All charts indicate biofilm formation at 20 h of growth expressed as the percentage of cell index (CI) compared with the control without antibiotic. Values below 100% indicate biofilm inhibition, whereas values over 100% indicate biofilm induction, in comparison with the biofilm mass achieved in the absence of each antibiotic.