FIG 1.

Impact of chloramphenicol and rifampin on paromomycin-promoted cytoplasmic membrane depolarization in wild-type P. aeruginosa. Cytoplasmic membrane depolarization, as assessed by DiBAC (4) fluorescence, was measured over time following exposure of P. aeruginosa to various antimicrobials added at 0 h. (A) Wild-type P. aeruginosa K767 exposed to 1× MIC of paromomycin (PAR; 256 μg/ml) in the absence or presence of 128 μg/ml of chloramphenicol (CAM). Untreated K767 was included as a control. (B) P. aeruginosa K767 and its amgR deletion derivative exposed to 1× MIC of paromomycin (PAR; 256 μg/ml). Untreated controls are also shown. (C) P. aeruginosa K767 exposed to 1× MIC of paromomycin (PAR; 256 μg/ml) or 1× MIC of gentamicin (GEN; 2 μg/ml) in the absence or presence of 8 μg/ml of rifampin (RIF). Untreated K767 was included as a control. The data are means ± standard errors of the means (SEMs) from 3 independent experiments.