cecropin-p1-li and Pseudomonas-Infections

Procedure of manufacturing

Topics: Animals; Anti-Infective Agents; Cefazolin; Humans; Immunomodulation; Kalanchoe; Male; Peptides; Plant Extracts; Plants, Genetically Modified; Pseudomonas aeruginosa; Pseudomonas Infections; Rats; Rats, Wistar; Recombinant Proteins; Staphylococcal Infections; Staphylococcus aureus; Swine; Wound Healing; Wound Infection

The in-vitro activity of cecropin P1, indolicidin, magainin II, nisin and ranalexin alone and in combination with nine clinically used antimicrobial agents was investigated against a control strain, Pseudomonas aeruginosa ATCC 27853 and 40 clinical isolates of P. aeruginosa. Antimicrobial activities were measured by MIC, MBC and viable count. In the combination study, the clinically used antibiotics were used at concentrations close to their mean serum level in humans in order to establish the clinical relevance of the results. To select peptide-resistant mutants, P. aeruginosa ATCC 27853 was treated with consecutive cycles of exposure to each peptide at 1 x MIC. The peptides had a varied range of inhibitory values: all isolates were more susceptible to cecropin P1, while ranalexin showed the lowest activity. Nevertheless, synergy was observed when the peptides were combined with polymyxin E and clarithromycin. Consecutive exposures to each peptide at 1 x MIC resulted in the selection of stable resistant mutants. Cationic peptides might be valuable as new antimicrobial agents. Our findings show that they are effective against P. aeruginosa, and that their activity is enhanced when they are combined with clinically used antimicrobial agents, particularly with polymyxin E and clarithromycin.

Topics: Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Colony Count, Microbial; Drug Resistance, Microbial; Drug Synergism; Drug Therapy, Combination; Humans; Magainins; Microbial Sensitivity Tests; Nisin; Peptides; Peptides, Cyclic; Pseudomonas aeruginosa; Pseudomonas Infections; Xenopus Proteins