B. subtilis 168 develops resistance against rifampicin (rif) but not against DR5026.

B. subtilis was incubated with subcytotoxic concentrations of rif (starting at 0.01 mg/L; MIC 0.06 mg/L) and DR5026 (0.5 mg/L MIC ~ 3 mg/L) and grown for 24 h. Then, aliquots of the cultures were transferred to new tubes with fresh medium and a two-fold increased concentration of the active compound. A binary representation is shown; 1 indicates growth of the cells, i. e. their resistance to the respective compound; 0 represents lack of growth—the cells were sensitive to the compound and no resistant cell appeared within the time frame of the experiment. The experiment was conducted in three biological replicates with the same results.