Rapid differentiation of virulent and avirulent strains of Newcastle disease virus by RT-PCR

In terms of the fusion(F) protein gene sequences of Newcastle disease virus(NDV) and the difference of the sequence at F protein gene cleavage sites between the virulent and avirulent strains of the NDV,three pairs of specific oligonucleotide primers were designed.Eleven NDV strains including field isolates from chickens and pheasant,2 NDV standard virulent and avirulent strains(F48E8 and LaSota strain) were detected through RT-PCR amplification.The results indicated that 11 NDV strains could be differentiated as virulent and avirulent strains by RT-PCR,and the results were accordant basically with the differentiating result of conventional pathogenicity test which included MDT,ICPI and IVPI.So RT-PCR was proved to be used for the rapid diagnosis of ND and differentiation of NDV virulent and avirulent strains.