Transcriptional Attenuation Controls Macrolide Inducible Efflux and Resistance in Streptococcus pneumoniae and in Other Gram-Positive Bacteria Containing mef/mel(msr(D)) Elements
Fig 2
β-galactosidase activity of promoter mutations in the mef(E)-lacZ reporter locus.
XZ7042 (squares) is the reporter strain generated by insertion of a mef(E)-lacZ fusion into the pneumococcal β-galactosidase gene bgaA; XZ7049 (diamonds), promoterless lacZ strain; XB05 (circles), strain containing the mef(E) promoter region deletion (Δ-41-(-5)) in the mef(E)-lacZ fusion in the bgaA locus. Dashed lines and open symbols, non-inducing conditions; solid lines and closed symbols, inducing conditions (treated with erythromycin at a concentration equal to 10-1 erythromycin MIC). Bars represent the standard error of the mean (SEM) of experiments performed in duplicate.