Figure 2 Download asset Open asset Tn-Seq identifies genes required for antibiotic tolerance in M. abscessus (Mabs). Antibiotic conditions were as described above. Additionally, we observed that the ΔblaR mutant, as well as the ΔpafA mutant, displayed a marked defect in resumption of growth after removal of antibiotics (Figure 3—figure supplement 1). In rich media, where the ΔkatG mutants have a moderate survival defect, the katG+ strain had roughly a 50-fold increase in viable cells relative to the katG- strain. We found that the MICs for each of these strains were unchanged, demonstrating that these mutants were not more readily inhibited by these antibiotics (Figure 4C and F).