Figure 2. Effect of amicoumacin A (A and B) and vancomycin (C and D) on S. aureus COL.

(A) COL was grown in TSB and exponential growth phase cultures were divided into two flasks. Amicoumacin-A-treated (closed circles) and -untreated cultures (open circles) were further incubated and the optical density at 600 nm was measured at hourly intervals. Effect of inhibitory levels of amicoumacin A during longer cultivation is shown in the insert of Figure 2A. (B) The cultures in (A) were used to examine viable cell counts by plating diluted cells on TSB agar. (C) COL was treated with 10 µg/ml of vancomycin and growth was monitored as described in (A). (D) The cultures in (C) were used to examine viable cell counts. The data are the average of three independent experiments with standard deviations.