FIG. 5.

Protease activities of supernatants from P. aeruginosa cultures grown either without antibiotics (black bar) or in the presence of 2 μg/ml AZM (bar with horizontal lines), 8 μg/ml AZM (bar with vertical lines), 0.25 μg/ml CFT (dark gray bar), or 0.04 μg/ml CPR (light gray bar). The ΔlasI-ΔrhlI mutant of PAO1 was also included in the experiment but did not produce a measurable concentration of protease (last slot [no column visible]). The graph is based on the average results of three independent experiments. *, P < 0.05; **, P < 0.01 (Dunnett's test).