Detection of New castel (Fgene)in Suspected broiller Flocks in Southern Khorasan Province.
2006
Kianizadeh, Mahdi
Newcastle disease (ND) is a contagious viral disease of many avian species particularly domestic poultry. In spite of performing vaccination program world widely, ND remains as a constant threat to commercial poultry. Although ND is endemic in Iran, but some devastating outbreaks are reported across the country annually. In this study 3 Newcastle disease viruses (NDV); (ND2/BIR85, ND6/BIR85, ND9/BIR85) were isolated from different broiler flocks in southern Khorasan province . The NDV isolates were genetically analyzed based on 851 nucleotides segment, which include the region encoding the cleavage activation site of the fusion (F) protein gene. The sequence results of the NDV isolates were compared with the sequence of 6 Iranian ND viruses, isolated formerly. Some international and regional country NDV isolates (Data from GenBank) were used for phylogentically analysis. Two out of three current NDV isolates showed conserved amino acid motif 111GRRQRRF117 at cleavage site as former Iranian NDV isolates, presented virulent ND virus. Since amino acid mutation (R K) at position 115, cleavage site motif of ND9/BIR85 isolate, was 111GRRQKRF117 that is first report from Iranian ND virus isolate. Due to amino acid substitution R K, ND9/BIR85 isolate lost glycozylation site at position N85. In phylogenic analysis, the Iranian ND isolates formed separate group. ND virus isolates from Pakistan showed less distances from the root. Based on our results, ND viruses are evolving and year-to-year changes will affect on virulence and emerging new genotype. To establish an effective control program for Newcastle disease, regular epidemiologically and genetically studies on circulating ND viruses in wild and domestic birds are needed.
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