640. Efficacy of the Use of Bacteriophages to Combat Pectobacterium atrosepticum

BACKGROUND: This inquiry aimed to investigate the potential of bacteriophages vB_PatP_CB3, vB_PatP_CB4, and vB_PatP_CB5 as methods for controlling the spread of Pectobacterium atrosepticum, a bacterial pathogen that causes black-leg disease and extensive crop damage. Structure of Podovirus [Figure: see text] Morphology of typical N4-like podovirus (Anatomy of an N4-like Podovirus phage, (adapted from Insight into DNA and Protein Transport in Double-stranded DNA Viruses: The Structure of Bacteriophage N4, J. McPartland, et al.)) Soft Rot in Potato [Figure: see text] Pectobacterium atrosepticum infection in potato (Pectobacterium atrosepticum infection in Solanum tuberosum, the common potato (M. Kuznetsova All-Russian Institute of Phytopathology)) METHODS: Phages were initially selected based on the location of isolation of the phage and its proximity to a field with a known current, or recent previous, Pectobacterium atrosepticum infection among potato crops. Phages were narrowed down by the specificity of their receptor-binding proteins for the protein receptors on the bacterium cell wall, as determined by FASTA sequence comparison between phage tail fiber RBPs and bacterial integral glycoproteins. A standard serial dilution and phage titration protocol in conjunction with a plaque assay were subsequently used to evaluate the efficacy of each phage, both individually and in a cocktail. Plaque Assay Diagram [Figure: see text] Standard plaque assay procedure used inoculate plates to obtain plaques RESULTS: Plaque assays showed that vB_PatP_CB5 produced a large number of plaques, indicating successful cell lysis and bacteriophage propagation within the bacterial colony. In contrast, vB_PatP_CB3 and vB_PatP_CB4 produced no measurable plaques. Plaques on Bacterial Lawn [Figure: see text] Observed plaque formation after initial 24 hour period Plaque Charts from Trial 1 [Figure: see text] Plaque formation from trial 1 Plaque Charts from Trial 3 [Figure: see text] Plaque Charts from Trial 3 CONCLUSION: Based on these findings, it was concluded that vB_PatP_CB5 is the most effective at lysing and controlling growth of P. atrosepticum. These results have implications for the development of new phage-based treatments for black-leg disease and for limiting the associated crop damage. DISCLOSURES: All Authors: No reported disclosures