Cationic antimicrobial peptide and its poly-N-substituted glycine congener: Antibacterial and antibiofilm potential against A. baumannii

Biochem Biophys Res Commun. 2019 Oct 20;518(3):472-478. doi: 10.1016/j.bbrc.2019.08.062. Epub 2019 Aug 21.

Abstract

Acinetobacter baumannii is one of the clinically important nosocomial pathogen that has become resistant to most of the conventional antimicrobials. Biofilms formed by A. baumannii are difficult to eradicate, thereby highlighting the need for new therapeutic options to treat biofilm associated infections. Antimicrobial peptides have recently emerged as new alternatives to conventional antibiotics, but peptides often suffer with drawbacks such as poor proteolytic stability and high cost of production. To tackle these limitations, mimetics based on antimicrobial peptides are usually designed and synthesized. In this study we have designed and synthesized a peptoid based on a minimum amphipathic template of a twelve residue cationic peptide. Antimicrobial evaluation of peptide and peptoid was carried out against biofilm producing A. baumannii strains. Further, proteolytic stability study of these compounds was carried out in human serum and morphological alterations caused by them on A. baumannii were visualized by SEM analysis. In addition, these compounds were found to be non toxic to human erythrocytes at their minimum inhibitory concentrations against A. baumannii strains. Overall results obtained in this study suggest that these compounds might be potential antimicrobial agents against biofilm forming A. baumannii and it may be postulated that their mode of action on A. baumannii is disruption of bacterial cell membrane.

Keywords: A. baumannii, cationic; Antimicrobial peptide; Biofilm; Pathogenic bacteria; Peptoid.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter Infections / drug therapy
  • Acinetobacter Infections / microbiology
  • Acinetobacter baumannii / drug effects*
  • Acinetobacter baumannii / physiology
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Antimicrobial Cationic Peptides / chemistry
  • Antimicrobial Cationic Peptides / pharmacology*
  • Biofilms / drug effects
  • Drug Design
  • Humans
  • N-substituted Glycines / analogs & derivatives
  • N-substituted Glycines / pharmacology*

Substances

  • Anti-Bacterial Agents
  • Antimicrobial Cationic Peptides
  • N-substituted Glycines