Effect of Subinhibitory Concentrations of Macrolides on Expression of Flagellin in Pseudomonas aeruginosa and Proteus mirabilis
AbstractEffect of Subinhibitory Concentrations of Macrolides on Expression of Flagellin in Pseudomonas aeruginosa and Proteus mirabilis Kumiko Kawamura-Sato 1 , 2 , Yoshitsugu Iinuma 2 , Tadao Hasegawa 1 , Toshinobu Horii 1 , Takafumi Yamashino 1 , and Michio Ohta 1 , * Department of Bacteriology, 1 and Department of Clinical Laboratory Medicine, 2 Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, Aichi 466-8550, Japan ABSTRACT In the present study we showed by molecular analysis that the inhibition of motility by macrolides in Proteus mirabilis and Pseudomonas aeruginosa was well correlated with the loss of the expression of flagellin. Erythromycin, clarithromycin, and azithromycin at subinhibitory concentrations (sub-MICs) suppressed the expression of flagellin dose dependently. Azithromycin had the strongest inhibitory effect on the expression of P. aeruginosa flagellin, whereas 16-membered rokitamycin had only a weak inhibitory effect. These results indicate the potential effectiveness of sub-MICs of erythromycin, clarithromycin, and azithromycin for the treatment of patients with P. mirabilis and P. aeruginosa infections.