FIG 5 .

E. coli CFT073 persistence in the presence of amino acids. Cultures were grown in 0.4% glucose M9 minimal medium as described in Materials and Methods and diluted 20-fold into 0.2% glucose M9 minimal medium either containing or lacking a mixture of the 20 standard l-amino acids, each at 100 µg/ml, and containing or lacking ampicillin (100 µg/ml). ♦, E. coli CFT073; ■, E. coli CFT073 plus ampicillin; ▲, E. coli CFT073 plus amino acids; ●, E. coli CFT073 plus amino acids plus ampicillin. Bars representing standard errors of the means of counts from 2 independent experiments are presented for each time point. At 6 h and 24 h, the approximately 100-fold differences between E. coli CFT073 persisters and E. coli MG1655 persisters in the presence of ampicillin are statistically significant (P = 0.002 and P = 0.05, respectively).