Antimicrobial Peptides and Drug Resistant Bacteria

Antibiotics have long provided effective treatment against bacterial infections. The creation of drugs like penicillin, streptomycin, and tetracycline allowed doctors to treat common bacterial infections that were once debilitating and even fatal. As antibiotic use has grown over the past several decades, bacteria have developed modes of resistance that have rendered some antibiotics useless. As these “super bugs” have become more resilient and resistant to treatment, researchers have begun to explore new ways of treating infections. Research has turned toward the use of antimicrobial peptides as an alternative to traditional antibiotics in treating drug resistant bacteria.

Antimicrobial peptides, also referred to as defensins, are short chains of amino acids that act against microorganisms. In plants and animals these peptides are made up of anywhere between 15 and 45 amino acid residues, and they are usually cationic, meaning that they contain higher amounts of lysine and arginine (Hancock and Lehrer 82). The peptides are produced as part of the body’s innate immune system, and they may be continuously present or produced in response to injury and infection. Because antimicrobial peptides are incorporated in innate immunity and are considered part of the body’s second line of defense against infection, they are often found in areas that may have close contact with environmental pathogens. These areas include, “the skin, ear, and eye, on epithelial surfaces, including the tongue, trachea, lungs, and gut, and in the bone marrow and testes” (Hancock and Scott 8856).

Antimicrobial peptides fall into two major categories based on the length of the peptide sequences between cysteine residues, with subfamilies of - and ...

... middle of paper ...

...a?” Nature Reviews Microbiology 3.3 (2005): 238-250. Academic Search Complete. Web.

10 April 2014.

Ganz, Thomas. “Defensins: Antimicrobial Peptides in Innate Immunity.” Nature Reviews Immunology 3.9 (2003): 710-720. Academic Search Complete. Web. 10 April 2014.

Hancock, Robert E.W, and Monisha G. Scott. “The Role of Antimicrobial Peptides in Animal Defenses.” Proceedings of the National Academy of Sciences of the United States of America 16.97 (2000): 8856-8861. Google Scholar. Web. 10 April 2014.

Hancock, Robert E.W, and Robert Lehrer. “Cationic Peptides: A New Source of Antibiotics.”

Trends in Biotechnology 16 (1998): 82-88. Google Scholar. Web. 10 April 2014.

Reddy, K.V.R, and R.D. Yedery, and C. Aranha. “Antimicrobial Peptides: Premises and Promises.” International Journal of Antimicrobial Agents 24 (2004): 536-547. Google Scholar. Web. 10 April 2014.