FIG. 2.

Effect of macrolide antibiotics on bacterial motility and flagellin expression. P. mirabilis (A) and P. aeruginosa (B) were grown on plates with increasing doses of macrolide antibiotics for 18 h, and the motility and the flagellin preparation of each bacterium were analyzed as described in the text. Results are expressed as means ± standard deviations (error bars) of three experiments. Asterisks indicate statistical difference (P < 0.05) from the control growth without antibiotics.