A low concentration of azithromycin inhibits the mRNA expression of N -acyl homoserine lactone synthesis enzymes, upstream of lasI or rhlI , in Pseudomonas aeruginosa

• Published in: Pulmonary pharmacology & therapeutics Vol. 22; no. 6; pp. 483 - 486
• Main Authors: Kai, Toshihiro, Tateda, Kazuhiro, Kimura, Soichiro, Ishii, Yoshikazu, Ito, Hideaki, Yoshida, Hiroaki, Kimura, Toru, Yamaguchi, Keizo
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.12.2009
• Subjects: Acyl-Butyrolactones - metabolism; Anti-Bacterial Agents - pharmacology; Azithromycin - pharmacology; Bacterial Proteins - biosynthesis; Bacterial Proteins - genetics; DNA microarray; Macrolide; Medical Education; Microarray Analysis; Pseudomonas aeruginosa; Pseudomonas aeruginosa - drug effects; Pseudomonas aeruginosa - genetics; Pseudomonas aeruginosa - metabolism; Pulmonary/Respiratory; Quorum-sensing; Reverse Transcriptase Polymerase Chain Reaction; RNA, Bacterial - biosynthesis; RNA, Messenger - biosynthesis; Signal Transduction - drug effects; DNA microarray; Pseudomonas aeruginosa; Quorum-sensing; Macrolide
• ISSN: 1094-5539; 1522-9629
• DOI: 10.1016/j.pupt.2009.04.004

Abstract Low-dose macrolides are effective therapy in patients with chronic lung infections, but the mechanisms of action are unclear. In this study, we performed DNA microarray analysis of Pseudomonas aeruginosa after treatment with a low concentration of azithromycin. We found that a sub-MIC of azithromycin didn't change mRNA expression of quorum-sensing related genes ( lasI , lasR , rhlI , rhlR , vft , rsaL ), but lowered expression of most N -acyl homoserine lactone (AHL) synthesis enzymes upstream of lasI and rhlI . We propose that small down regulation of these enzymes cumulatively resulted in a larger decrease of AHL production and inhibition of quorum-sensing in P. aeruginosa.