|AMP > Introduction :
The continuous use of antibiotics has resulted in multi-resistant bacterial strains all over the world and as expected, hospitals have become breeding grounds for human-associated micro organisms. Nonetheless, the same time-bomb effect is slowly developing with animal-associated pathogens in commercially driven activities, such as aquaculture and confined poultry breeding, where the indiscriminate use of antibiotics is perceivedasessential for industries survival. Consequently, there is an urgent need to search for alternatives to synthetic antibiotics. The discovery of two classes of antimicrobial peptides, non-ribosomally synthesized (Hancock and Chapple, 1999)- present in bacteria - lower eukaryotes and plants - and ribosomally-synthesized peptides, of wider distribution , provided a new therapeutic strategy to fight micro organisms. Recent studies show that several cationic and non-cationic peptides expressed in many vertebrate, invertebrate and bacterial species act synergistically to improve immune responses.
The knowledge acquired in the
past two decades and the discovery of new groups of antimicrobial
peptides make natural antibiotics the basic element of a novel
generation of drugs for the treatment of bacterial and fungal infections
. In addition, the wide spectrum of antimicrobial activities reported
for these molecules suggests they potential benefit in the treatment of
cancer and viral or parasitic infections . Different
therapeutic applications of these compounds, from topical
administration to systemic treatment of infections, have been developed
by several biotechnological companies Interestingly, to date,
clinical Phase I and II trials have shown a limited resistance for the
bacterial strains tested (Zasloff, 2002). These features make
the antibiotic peptides a powerful arsenal of molecules that could be
the antimicrobial drugs of the new century as an innovative response to
the increasing problem of MDR .
R.E.W. and CHAPPLE, D.S. Peptide antibiotics (Minireview). Antimicrobial
Agents Chemotherapy, 1999, vol. 43, no. 6, p. 1317-1323.
ZASLOFF, M. Antimicrobial peptides of multicellular organisms. Nature, 2002, vol. 415, no. 6870, p. 389-395.