Title: Characterization of bacteriophages virulent for Clostridium perfringens and identification of phage lytic enzymes as alternatives to antibiotics for potential control of the bacterium Author
Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 17, 2012
Publication Date: N/A
Technical Abstract: There has been a resurgent interest in the use of bacteriophages or their gene products to control bacterial pathogens as alternatives to currently utilized antibiotics. Clostridium perfringens is a Gram-positive, spore-forming anaerobic bacterium that plays a significant role in human food-borne disease as well as non-food-borne human, animal and poultry diseases. Countries that have complied with the ban on antimicrobial growth promoters (AGP) in feeds have reported increased incidences of C. perfringens-associated necrotic enteritis in poultry. To address these issues, new antimicrobial agents, putative lysins encoded by the genomes of bacteriophages, are being identified in our laboratory. Poultry intestinal material, soil, sewage and poultry processing drainage water were screened for virulent bacteriophages that could lyse the bacterium C. perfringens and produce clear plaques in spot assays. Bacteriophages were isolated that had long non-contractile tails, members of the family Siphoviridae, and with short non-contractile tails, members of the family Podoviridae. Several phage genes were identified that encoded N-acetylmuramoyl-l-alanine amidases, lysozyme-endopeptidases and a zinc carboxypeptidase domain that has not been previously reported in viral genomes. Two putative phage lysin genes (ply) were cloned and expressed in Escherichia coli, and the resultant proteins were purified to near homogeneity. The recombinant lysins were amidases capable of lysing both parental phage host strains of C. perfringens as well as other strains of the bacterium in spot and turbidity reduction assays, but did not lyse any clostridia beyond the species. Consequently, bacteriophage gene products may eventually be utilized to target specific bacterial agents to control animal and human diseases without having deleterious effects on beneficial bacteria.