FIG 1.
Potentiating effect of octoclothepin (Oct) on meropenem (Mer) or meropenem-clavulanate (Clav) combinations against mycobacteria as determined by mean log10CFU counts. (a) Evaluation of potentiating effect of octoclothepin on meropenem against M. smegmatis (light-gray bars). TR62 (parAMs::Tn) was included in the experiment to determine the extent to which octoclothepin phenocopies the parAMs mutation. TR62:parAMs was included as a complementation control. Strains were incubated with the above-mentioned antibiotic/inhibitors for 60 h. Untreated strains were plated at 0 h (open bars) and 60 h (black bars) as controls. As an additional control, the designated strains were treated with sublethal concentrations of the above inhibitors (dark-gray bars). WT, wild type. (b) Evaluation of potentiating effect of octoclothepin on meropenem and meropenem-clavulanate combinations against M. tuberculosis H37Ra (light-gray bars). M. tuberculosis H37Ra was incubated with the above-mentioned antibiotic/inhibitor for 11 days. Untreated M. tuberculosis H37Ra was plated on day 0 (open bar) and day 11 (black bar) as controls. As an additional control, M. tuberculosis H37Ra was treated with sublethal concentrations of the above inhibitors (dark-gray bars). Compound concentrations are represented in mg/liter. The error bars represent standard deviations. Results shown are representative of two biological replicates.