High-level antibiotic resistance in Pseudomonas aeruginosa biofilm: the ndvB gene is involved in the production of highly glycerol-phosphorylated β-(1→3)-glucans, which bind aminoglycosides

Pseudomonas aeruginosa is an opportunistic pathogen which affects immuno-compromised individuals and causes life-threatening infections in cystic fibrosis (CF) patients. Colonization of CF lung by P. aeruginosa involves a biofilm mode of growth, which is promoted by the production of exopolysaccharides. These polymers are essential components of the extracellular biofilm matrix. P. aeruginosa possesses several clusters contributing to the formation of the matrix, including the pel or psl genes. In the present study, we identified anionic cyclic glucans produced by P. aeruginosa, which are associated with the matrix of strains PAK∆retS and PA14. Their structure has been elucidated using chemical analysis, oneand two-dimensional NMR techniques, and mass spectrometry. They belong to a family of cyclic β-(1→3)-linked glucans of 12-16 glucose residues with 30-50% of glucose units substituted by 1-phosphoglycerol at O-6. ∗ Corresponding author. Tel. +1-613-9900832; Fax +1-613-9529092; e-mail: Evguenii.Vinogradov@nrccnrc.gc.ca Glycobiology Advance Access published March 26, 2010