CHARACTERIZATION OF NEWCASTLE DISEASE VIRUS STRAINS ISOLATED FROM MIGRATORY BIRDS IN RUSSIA
Research was carried out to investigate two highly pathogenic Newcastle Disease Virus (NDV) strains isolated from dead wild birds. The phylogenetic analysis has shown that both isolated strains belong to class II genotype 7 and most closely related to the strains previously isolated from poultry in China. High mortality (IVPI=2) in chickens was observed. Morphological investigation has revealed disruptions of brain, trachea and lung tissues in chickens, no damage to the intestine was observed. The genetic divergence from LaSota vaccine strain (class II genotype 2) commonly used in Russia makes these viruses a high-risk agent for poultry. The findings obtained are indicative of a possibility for highly pathogenic NDV viruses to be transmitted from Southeast Asian countries to Russia by migrating birds that can complicate the ND situation.