Determination of the Infection Dynamics of Escherichia coli O157:H7 by Bacteriophage ΦV10

ΦV10 is an <i>Escherichia coli</i> O157:H7-specific bacteriophage that has been used to develop luminescent reporter assays for the detection of this important foodborne pathogen. Previous work demonstrated the specificity of ΦV10 for infection of <i>E.coli</i> O157:H7 through interaction with the O157 antigen. In addition, modification of the lipopolysaccharide (LPS) via O-acetylation prevents ΦV10 infection in an <i>E. coli</i> O157:H7 expressing a phage-encoded O-acetylase gene. Through assays for phage binding, plaque formation, and lysogeny using non-O157:H7 and O157: non-H7 strains, as well as complementation of an O157:H^- strain, it is demonstrated in this study that both the somatic O157 antigen and flagellar H7 antigen are required for productive infection of <i>E. coli</i> O157:H7 by ΦV10. Together, the results indicate that the O157 antigen is required for phage binding and that the H7 antigen is necessary to complete the infection process.