Figure 6

Fold-change in fluorescence of ethidium bromide at steady state level of accumulation in efflux pump gene deletion mutants compared with the parental isolate. Three separate experiments showed consistent results and representative examples are shown. Standard deviation represents variation between biological replicates. Asterisks indicate significant differences (P ≤ 0.05) in accumulation compared with the parental isolate or with addition of an EI. Panel A, Fold-change in level of ethidium bromide accumulated by R2 and mutants. Panel B, Fold-change in level of ethidium bromide accumulated by R2 and mutants with addition of EIs. Panel C, Fold-change in level of ethidium bromide accumulated by DB and mutants. Panel D, Fold-change in level of ethidium bromide accumulated by DB and mutants with addition of EIs. Dark grey, no EI; light grey, CCCP; white, PAβN.