The formation of biofilms contributes significantly to bacterial resistance to
antibiotics, innate host defences and in persistent infections. In this era of multidrugresistant
bacterial infections, the discovery of novel antibacterial agents is required to
treat infections that kill these organisms via novel mechanisms of action. Antimicrobial
peptides, also known as host-defence peptides are short polypeptides (<40 amino acids)
and are an integral part of the innate immune system that protects a host from bacterial
infection. This chapter discusses the potential of anti-microbial peptides as an antiinfective
agent, its advantages, disadvantages, their structures and mechanisms of
action. A perception of the bacteriostatic and bactericidal mechanism of antimicrobial
peptides is required to facilitate the rational design of novel antimicrobial agents. Thus
a deeper understanding of the mechanism of natural AMPs will also aid in developing
new antibacterial agents. Furthermore, the chapter also considers the possibility of the
use of synthetic antimicrobial peptides containing both natural and unnatural amino
acids as anti-infective agents. Apart from the antibacterial property, AMPs are also
being used as drug delivery vectors to transport the cell impermeable drugs to the cell
interior. The diversity and broad spectrum antimicrobial activity of AMPs along with
its multidimensional properties could be exploited as a potential and promising drug
candidate.
Keywords: Antimicrobial peptides, Human β-defensin, Indolicidin, Synthetic
peptide, biofilms, host defences, host-defence peptides, unnatural amino acids, β-
peptides.
