Submitted to: Scientific and Technical Review
Publication Type: Review Article
Publication Acceptance Date: 4/1/2016
Publication Date: 6/1/2016
Citation: Kim, W., Lillehoj, H.S., Gay, C.G. 2016. Genomics for the identification of novel antimicrobials. Scientific and Technical Review. 35(1):95-103. doi: 10.20506/rst.35.1.2420.
Technical Abstract: There is a critical need in animal agriculture for developing novel antimicrobials and alternative strategies to reduce the use of antibiotics and address the challenges of antimicrobial resistance. High-throughput gene expression analysis is providing new tools that are enabling the discovery of host-derived antimicrobial peptides. Examples of gene-encoded natural antibiotics that have gained attention include antimicrobial peptides such as granulysin and its multi-species homologs called NK-Lysin, which provide a protective response against a broad range of microbes and are a principal component of innate immunity in vertebrates. Both granulysin and NK-lysin are localized in cytolytic granules in natural killer and cytotoxic T lymphocytes. Host-derived NK-lysins that were first described in mammals, are also found in avian species, and have been shown to have antimicrobial activities that could potentially be used to control important poultry pathogens. Morphological alterations observed following chicken NK-lysin binding to Eimeria sporozoites and Escherichia coli membranes indicate damage and disruption of cell membranes, suggesting that NK-lysin kills pathogenic protozoans and bacteria by direct interaction. Genotype analysis revealed that the biological activity of chicken NK-lysin peptides derived from certain alleles were more effective at killing pathogens and could potentially affect susceptibility to diseases. Although the discovery of the host-derived antimicrobial peptides described in this paper may not by themselves replace the benefits of antibiotics seen in animal production, their use as specific treatments based on their known mechanisms of actions is showing promising results.