Premium
Activity of antimicrobial peptides in the presence of polysaccharides produced by pulmonary pathogens
Author(s) -
Benincasa M.,
Mattiuzzo M.,
Herasimenka Y.,
Cescutti P.,
Rizzo R.,
Gennaro R.
Publication year - 2009
Publication title -
journal of peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 66
eISSN - 1099-1387
pISSN - 1075-2617
DOI - 10.1002/psc.1142
Subject(s) - antimicrobial peptides , microbiology and biotechnology , pseudomonas aeruginosa , cathelicidin , cystic fibrosis , antimicrobial , biofilm , biology , bacteria , chemistry , genetics
Abstract Antimicrobial peptides (AMPs) are secreted in the airway and contribute to initial defence against inhaled pathogens. Infections of the respiratory tract are a major cause of morbidity and mortality in preterm newborns and in patients with cystic fibrosis (CF). In this latter group, the state of chronic lung infection is due to the ability of bacteria to grow as mucoid biofilm, a condition characterised by overproduction and release of polysaccharides (PSs). In this study, we investigate the effect of PSs produced by lung pathogens such as Pseudomonas aeruginosa, Klebsiella pneumoniae and members of the Burkholderia cepacia complex on the antibacterial activity of structurally different peptides. The AMPs tested in this study include the cathelicidin LL‐37 and the β‐defensin hBD‐3 from humans, both released at the alveolar level, as well as peptides from other mammals, i.e. SMAP‐29, PG‐1 and Bac7(1‐35). Susceptibility assays, time killing and membrane permeabilization kinetics experiments were carried out to establish whether PSs produced by lung pathogens may be involved in the poor defence reaction of infected lungs and thus explain infection persistence. All the PSs investigated inhibited, albeit to a different extent, the antibacterial activity of the peptides tested, suggesting that their presence in the lungs of patients with CF may contribute to the decreased defence response of this district upon infection by PS‐producing microorganisms. The results also show that inhibition of the antibacterial activity is not simply due to ionic interaction between the negatively charged PSs and the cationic AMPs, but it also involves other structural features of both interactors. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.