FIG 9 .

E. coli CFT073 sdhA persistence in the presence of fumarate. Cultures were grown overnight in 0.4% glucose M9 minimal medium containing or lacking disodium fumarate (200 µg/ml) and then diluted 20-fold into 0.2% glucose M9 minimal medium containing or lacking fumarate, and persister cell assays were performed as described in Materials and Methods. ▲, E. coli CFT073 sdhA; ●, E. coli CFT073 sdhA plus ampicillin; ♦, E. coli CFT073 sdhA plus fumarate; ■, E. coli CFT073 sdhA plus fumarate 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 differences between E. coli CFT073 sdhA persisters in the presence and absence of fumarate are statistically significant (P = 0.013 and P = 0.046, respectively).