The role of antimicrobial peptides in preventing multidrug-resistant bacterial infections and biofilm formation

Abstract

Over the last decade, decreasing effectiveness of conventional antimicrobial-drugs has caused serious problems due to the rapid emergence of multidrug-resistant pathogens. Furthermore, biofilms, which are microbial communities that cause serious chronic infections and dental plaque, form environments that enhance antimicrobial resistance. As a result, there is a continuous search to overcome or control such problems, which has resulted in antimicrobial peptides being considered as an alternative to conventional drugs. Antimicrobial peptides are ancient host defense effector molecules in living organisms. These peptides have been identified in diverse organisms and synthetically developed by using peptidomimic techniques. This review was conducted to demonstrate the mode of action by which antimicrobial peptides combat multidrug-resistant bacteria and prevent biofilm formation and to introduce clinical uses of these compounds for chronic disease, medical devices, and oral health. In addition, combinations of antimicrobial peptides and conventional drugs were considered due to their synergetic effects and low cost for therapeutic treatment.

Keywords: dental plaque; lipopolysaccharide; mode of action; quorum sensing; synergetic effect.

Figure 1

Three typical modes of action of antimicrobial peptides against cytoplasmic membranes. (A) barrel-stave model; (B) toroidal pore model; (C) carpet model.

Figure 2

General overview of bacterial biofilm development. (1) reversible adsorption of bacteria; (2) irreversible attachment of bacteria; (3) production of extracelluar polymeric substance and biofilm growth; (4) maturation; (5) dispersion. After dispersion of the biofilm, bacteria move to other organs, tissues, or surfaces and a new biofilm is formed via stages (1)–(5).