Figure 1. Effect of fluoroquinolones alone or combined with caspofungin on biofilms from four selected strains.

Biofilms were incubated during 48 h in the absence or in the presence of the drugs (moxifloxacin (a–h black) or delafloxacin (i–p blue) at increasing concentrations and used alone (a–d and i–l) or combined (e–h and m–p) with 40 mg l⁻¹ caspofungin). The ordinate shows resorufin fluorescence (closed bars; left scale; expressed in percentage of the value measured in control conditions (no fluoroquinolone added)) and CFU (open bars; right scale; expressed in log₁₀ units). Data are the mean±s.d. of four replicates. Statistical analysis: multiple t-tests comparing data for fluoroquinolone alone or combined with caspofungin in the same conditions: ***P<0.001; **P<0.01; *P<0.05.