FIG. 5.

Survival of mutants whose putative persister genes were affected in exponential phase. (A) One-milliliter cultures were grown to exponential phase in MOPS minimal medium and treated with 5 μg/ml ofloxacin for 3 h. (B) Time-dependent killing studies of mutants whose persister genes were affected. Mutants with a prominent low-level-persistence phenotype in log phase were exposed to 5 μg/ml ofloxacin for the indicated times. Samples were diluted and spot plated on LB agar. The experiment was performed in triplicate, and error bars represent standard deviations. WT, wild type.