Potential novel therapeutic strategies in cystic fibrosis: antimicrobial and anti-biofilm activity of natural and designed α-helical peptides against Staphylococcus aureus, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia
1 Department of Biomedical Sciences, “G. d’Annunzio” University of Chieti, Via Vestini 31, 66100 Chieti, Italy
2 Center of Excellence on Aging, “G. d'Annunzio” University Foundation, Via Colle dell’Ara, 66100 Chieti, Italy
3 Department of Life Sciences, University of Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy
4 Center for Integrated Research, “Campus Biomedico” University, Via A. Del Portillo, 00128 Rome, Italy
5 "Bambino Gesù" Children's Hospital and Research Institute, Piazza Sant’Onofrio 4, 00165 Rome, Italy
BMC Microbiology 2012, 12:145 doi:10.1186/1471-2180-12-145Published: 23 July 2012
Treatment of cystic fibrosis-associated lung infections is hampered by the presence of multi-drug resistant pathogens, many of which are also strong biofilm producers. Antimicrobial peptides, essential components of innate immunity in humans and animals, exhibit relevant in vitro antimicrobial activity although they tend not to select for resistant strains.
Three α-helical antimicrobial peptides, BMAP-27 and BMAP-28 of bovine origin, and the artificial P19(9/B) peptide were tested, comparatively to Tobramycin, for their in vitro antibacterial and anti-biofilm activity against 15 Staphylococcus aureus, 25 Pseudomonas aeruginosa, and 27 Stenotrophomonas maltophilia strains from cystic fibrosis patients. All assays were carried out in physical-chemical experimental conditions simulating a cystic fibrosis lung. All peptides showed a potent and rapid bactericidal activity against most P. aeruginosa, S. maltophilia and S. aureus strains tested, at levels generally higher than those exhibited by Tobramycin and significantly reduced biofilm formation of all the bacterial species tested, although less effectively than Tobramycin did. On the contrary, the viability-reducing activity of antimicrobial peptides against preformed P. aeruginosa biofilms was comparable to and, in some cases, higher than that showed by Tobramycin.
The activity shown by α-helical peptides against planktonic and biofilm cells makes them promising “lead compounds” for future development of novel drugs for therapeutic treatment of cystic fibrosis lung disease.