Genetic and Filogenetic Characterization of some Newcastle Strains Isolated from Poultry in Albania

Abstract section. In this study, we present the molecular characterization and phylogenetic analysis of three strains of NDV, isolated from the Tirana region in Albania during the 2011-2014 years. Three strains with number 28, 29 and 31, isolated from a different farm of poultry in Tirana Region (Rural flocks), which were diagnosedclinically with the ND. The Intracerebral Pathogenicity Index in SPF bird one day old was determined by doing the proteolytic sequencing at the cleavage, and specifying the aminoacid motif at proteolytic cleavage site. More over we performed BLAST search and phylogenetic analysis of obtained RNA sequences. All strains replicated well in the SPF –chicken emryo eggs. The isolates displayed an aminoacid motif at the proteolytic cleavage site at the Fusion (F) protein with multiple basic amino acids as a well a Phenylalanine on position 117. For one isolate (28) numerous nucleotide positions had signals for at last two nucleotides, making it imposible to conclude on a specific sequence. The pathogenicity of all three isolates (28, 29 and 33), was assessed by the analysis of the F protein cleavage site and by standart ICPI. The ICPI (pathogenicity index) of our strains varies from of 1.85, 2 and 1.75, respectively which according [19,7] are typical for velogenic strains of NDV. We found that two NDV strain has a most close genetic relationship with the Serbia 2007 NDV, having 98% similarity at nucleotide level.Velogenic viscerotropic strains are considered endemic in our country.