Animals have a numerous antimicrobial systems that often evolved as part of host defense mechanisms. Many of the
antimicrobial agents inherent to animals are in the form of antimicrobial peptides (polypeptides). Antimicrobial peptides
have been found in every living organism including bacteria, fungi, plants, and animals [73]. Antimicrobial peptides are
widely distributed in nature and used by the host as essential components of nonspecific defense systems [9, 73]. They
form a promising solution to antibiotic resistance because of the fact that the specific molecular sites are not targeted
and peptides also can destruct the membranes rapidly which does not allow sufficient time for even fast-growingbacteria to mutate [9]. Antimicrobial peptides kill both Gram-positive and Gram-negative bacteria, and most peptides
have also shown antifungal and antiviral activities [10,11]. Several peptides with potential antimicrobials from animal
origin such as Pleurocidin, Lactoferrin, Defensins, and Protamine have been well documented.