Effects of Chlorophyll-Derived Efflux Pump Inhibitor Pheophorbide a and Pyropheophorbide a on Growth and Macrolide Antibiotic Resistance of Indicator and Anaerobic Swine Manure Bacteria

Figure 3

Initial (day 1) and final (day 7 or 14) MIC ranges of erythromycin (μg mL⁻¹) for naïve (a), (b) and induced (c), (d) Gram-positive and -negative bacterial reference strains. Assays were supplemented with either 0 (EtOH 0.5, EtOH 50), 0.5, or 50 μg pheophorbide a (php 0.5, php 50) or pyropheophorbide a (pyp 0.5, pyp 50) mL⁻¹.

(a)

(b)

(c)

(d)