title: Comparative analysis of the bactericidal activities of amphibian peptide analogues against multidrug-resistant nosocomial bacterial strains.
abstract: Due to the widespread resistance of bacteria to the available drugs, the discovery of new classes of antibiotics is urgently needed, and naturally occurring antimicrobial peptides (AMPs) are considered promising candidates for future therapeutic use. Amphibian skin is one of the richest sources of such AMPs. In the present study we compared the in vitro bactericidal activities of five AMPs from three different species of anurans against multidrug-resistant clinical isolates belonging to species often involved in nosocomial infections (Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Acinetobacter baumannii). The peptides tested were temporins A, B, and G from Rana temporaria; the fragment from positions 1 to 18 of esculentin 1b [Esc(1-18)] from Rana esculenta; and bombinin H2 from Bombina variegata. When they were tested in buffer, all the peptides were bactericidal against all bacterial species tested (three strains of each species) at concentrations ranging from 0.5 to 48 microM, with only a few exceptions. The temporins were found to be more active against gram-positive bacteria, especially when they were assayed in human serum; Esc(1-18) showed fast and strong bactericidal activity, within 2 to 20 min, especially against the gram-negative species, which were killed by Esc(1-18) at concentrations ranging from 0.5 to 1 microM; bombinin H2 displayed similar bactericidal activity toward all isolates. Interestingly, while the activities of the temporins and bombinin H2 were almost completely inhibited in the presence of 20% human serum, the activity of Esc(1-18) against the gram-negative species was partially preserved in the presence of 40% serum. This property renders this peptide an attractive molecule for use in the development of new compounds for the treatment of infectious diseases.
authors.affiliation: Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche A. Rossi Fanelli, Sapienza Università di Roma, Rome, Italy.
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Mangoni
authors.forename: Giuseppantonio
authors.initials: G
authors.lastname: Maisetta
authors.forename: Mariagrazia
authors.initials: M
authors.lastname: Di Luca
authors.forename: Ludovica Marcellini Hercolani
authors.initials: LM
authors.lastname: Gaddi
authors.forename: Semih
authors.initials: S
authors.lastname: Esin
authors.forename: Walter
authors.initials: W
authors.lastname: Florio
authors.forename: Franca Lisa
authors.initials: FL
authors.lastname: Brancatisano
authors.forename: Donatella
authors.initials: D
authors.lastname: Barra
authors.forename: Mario
authors.initials: M
authors.lastname: Campa
authors.forename: Giovanna
authors.initials: G
authors.lastname: Batoni
mesh_terms: D000595:Amino Acid Sequence; D029845:Amphibian Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D001001:Anura / Q000145:classification / Q000378:metabolism; D003428:Cross Infection / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D008969:Molecular Sequence Data; D011506:Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D011898:Ranidae / Q000145:classification / Q000378:metabolism
chemical_list: D029845:Amphibian Proteins; D023181:Antimicrobial Cationic Peptides; D011506:Proteins; C510197:bombinin H2; C092874:esculentin protein, Rana esculenta; C104501:temporin