Pathotyping of Newcastle Disease Virus With a Filamentous Bacteriophage

Abstract

A filamentous phage bearing the peptide sequence TLTTKLY was isolated from a heptapeptide phage display library against newcastle disease virus (NDV). In order to investigate the potential of this specific phage as an immnological reagent in virus pathotyping, an enzyme-linked immunosorbent assay (ELISA)-based method was developed. This method can differentiate the velogenic strains from the mesogenic and lentogenic strains. An equilibrium-binding assay in solution showed that the interaction between the phage and the NDV strains gave rise to two widely differing dissociation constant (Kdrel ). Based upon the first Kdrel values, NV starins can be classified into two groups; the first comprises the velogenic strains, and the second consist of the mesogenic and lentogenic strains. These results indicate a high degree of correlation between the binding affinities and pathotayping of NDv strains using the TLTTKLY phage.