FIG 2.

Synergistic activity of indole-2-carboxamide derivatives with IPM and FOX in vitro. CFU counts of Cpd12 (A) and Cpd6 (B) given alone and in combination with imipenem (IPM) or cefoxitin (FOX). M. abscessus cultures were incubated at 30°C in CaMHB for 5 days in the presence of the indicated compounds (μg/ml) and plated on LB agar prior to CFU enumeration. (C) For CFU determination, the M. abscessus mutant A309P (spontaneous resistant strain to Cpd12 carrying the A309P mutation in MmpL3) was exposed to the indicated antibiotics (μg/ml) at 30°C in CaMHB for 5 days. Graphs represent the mean of three independent experiments completed in triplicate. Data are expressed as the mean ± standard deviation (SD). The statistical test used is a nonparametric Mann-Whitney t test in which the combinations were compared to the drugs alone. ns, nonsignificant; **, P ≤ 0.01; ***, P ≤ 0.001.