Isolation,Identification And Molecular Characteristics Of Pigeon Newcastle Disease Virus In Shandong Province

Pigeon Newcastle disease,so-called pigeon plague,caused by pigeon Newcastle disease virus,is an acute,febrile and highly contagious infectious disease in pigeons.Pigeon Newcastle disease virus is also called Pigeon Paramyxovirus type ?(PPMV-?).It has only one serotype.Pigeon Newcastle disease is the mutation result of avian Newcastle disease virus which have long stood in pigeons and adapted to the doves.PPMV-? is the mutant strain of avian paramyxovirus type ?.Pigeon Newcastle disease caused by pigeon paramyxovirus type ? virus which can infect dove with different breeds and ages.The virus spreads rapidly and causes great economic losses to pigeon industry.It is very important to prevent and control this disease in pigeon industry.In order to obtain the basic disease status information of the pigeon in Shandong province,20 pigeon farms were investigated in this research.Total 320 blood samples and anus swab samples were collected in these farms.The blood samples were used to detect the antibody titer of ND,and the anus swab samples were used to detect the virus.The results showed as following:(1)NDV antibody test result:the NDV HI antibody titer of most samples is below 1:64.The HI antibody titer of zero accounted for 18.7%and over 1:256 accounted for 19.96%.The average of ND antibody titer is 3.65 log 2,which showing that most of the pigeon in the farms had low levels of NDV antibody.(2)Viral isolation and identification:The NDV positive anal swab samples were disposed and inoculated into 9 days-old SPF embryo eggs.And 4 PPMV type ? strains were isolated from these samples.After plaque purification,they were selected to be sequenced for the F gene and HN genes.The results showed that the F protein cleavage motif of four PPMV-? isolates were 112 KRQKRF117,which being similar to the virulent cleavage motif.The phylogenetic tree of F gene and HN gene analysis showed that the four isolates were classified as classll genotype?b.The results of pathogenicity showed that The MDT values of four PPMV type ? strains were 62.4 h,66.1 h,84.2 h and 63.3 h,respectively.And the ICPI values were 1.34,1.42,0.97 and 1.36,respectively.It indicated that these strains were medium virulence strains.It should be very useful to prevent and control pigeon Newcastle disease in the future.