Potent and rapid antibacterial activity of the Protegrin-1 and its derivatives against different bacterial pathogens of animal production

Cher-un Limyada

Abstract

Statement of the Problem: Antibiotics have been used routinely in pig and poultry production, however, improper use of antibiotics has caused serious environmental and health risks, in particular antimicrobial resistance. Due to their unique mode of action, antimicrobial peptides are novel alternatives to traditional antibiotics for tackling the issue of bacterial drug resistance. Methodology & Theoretical Orientation: Protegrin-1 (PG-1) is an 18-amino-acid beta-hairpin antimicrobial peptide found in porcine leukocytes and belongs to the cathelicidin family.  It exhibited antimicrobial activity against many bacteria, fungi, and some enveloped viruses. In search for novel effective agents to combat swine and poultry gastrointestinal infections, a series of the PG-1 peptide and its truncated derivatives were synthesized chemically and their antibacterial activities were assessed.  Findings:  Among the peptides tested, PG-11, PG-12, and PG-13 peptides, which were the modified peptide of the parental PG-1 peptide, clearly demonstrated potential inhibitory activity against colistin resistant Listeria monocytogenes and tetracycline resistant Salmonella typhimurium with 100 µg/ml. Decreasing the cationicity and increasing random coil percentage of PG-1 increased the potency against intestinal bacteria.  Conclusion & Significance: The shortest PG-13 peptide is a promising antibacterial agent against intestinal pathogens of swine and poultry.