FIG 7.

Comparison of antibiotic relative potencies (C₂₀) expressed in multiples of the MIC with respect to viability (left panels) or biomass (right panels) for 2- and 11-day-old naive and induced biofilms of strain ATCC 49619 (upper panels [gray bars]) or R6 (lower panels [black bars]). AMX, amoxicillin; CLR, clarithromycin; SOL, solithromycin; LVX, levofloxacin; MXF, moxifloxacin. Values were calculated as means ± SEM (calculated from the 95% confidence interval band around the curve) using the Hill equation of the concentration-response curves presented in Fig. 3 to 5 and Fig. S1 and S2 in the supplemental material. (Also see Tables S1 and S2 in the supplemental material for numerical values.) Statistical analyses were performed by one-way ANOVA with Tukey's posttest for multiple comparisons; values with different letters are significantly different from each other (P < 0.05). Lowercase letters indicate comparison between antibiotics for each type of biofilm, and capital letters indicate comparison between different types of biofilms for each antibiotic. NA, not applicable (a “Top” value of the Hill equation of <80%). When not reached at the maximal value tested, C₂₀ values were set at 4 (log scale).