Figure 7.

Antibiotic tolerance of NTHi clinical strains biofilms is not dependent on biofilm size. MBEC assays were performed on each strain with a range of concentrations of amoxicillin, ceftriaxone, clarithromycin and azithromycin. The MBECs, or antibiotic concentrations at which bacterial counts were reduced to or below the LOD (1.5 × 10³ CFU mL⁻¹), are shown and specifically indicated if less than or equal to the greatest concentration tested: ^⁁ 64 μg mL⁻¹, * 4 μg mL⁻¹, + 256 μg mL⁻¹, # 32 μg mL⁻¹.