Repeated isolation of virulent Newcastle disease viruses of sub-genotype VIId from backyard chickens in Bulgaria and Ukraine between 2002 and 2013.

Here, we report the circulation of highly related virulent Newcastle disease viruses (NDV) in Bulgaria and Ukraine from 2002 until 2013. All of these NDV isolates have the same virulence-associated cleavage site ("RQKR↓F"), and selected ones have intracerebral pathogenicity index values ranging from 1.61 to 1.

Genetic diversity and mutation of avian paramyxovirus serotype 1 (Newcastle disease virus) in wild birds and evidence for intercontinental spread.

Avian paramyxovirus serotype 1 (APMV-1), or Newcastle disease virus, is the causative agent of Newcastle disease, one of the most economically important diseases for poultry production worldwide and a cause of periodic epizootics in wild birds in North America. In this study, we examined the genetic diversity of APMV-1 isolated from migratory birds sampled in Alaska, Japan, and Russia and assessed the evidence for intercontinental virus spread using phylogenetic methods. Additionally, we predicted viral virulence using deduced amino acid residues for the fusion protein cleavage site and estimated mutation rates for the fusion gene of class I and class II migratory bird isolates.

[Biological properties of velogenic strains of the Newcastle disease virus isolated in the Northern Caucasian region].

The results of the biological property investigation of two Newcastle virus strains isolated in Northern Caucasian region--NDV/Adigeya/duck/8/2008 and NDV/Adigeya/duck/15/2008--were presented. The phylogenetic analysis revealed that these strains belonged to genotype 7 of clade 2. Using molecular-biological analysis of established nucleotide sequences including proteolytic site of fusion peptide it was demonstrated that the strains were velogenic.

Ecology of influenza virus in wild bird populations in Central Asia.

The study provides the results of avian influenza virus surveillance in Central Asia during 2003-2009. We have analyzed 2604 samples from wild birds. These samples were collected in Kazakhstan (279), Mongolia (650), and Russia (1675).

[Characterization of the H5N1 influenza virus isolated during an outbreak among wild birds in Russia (Tuva Republic) in 2010].

The study of basic biological properties of H5N1 subtype strain isolated during an outbreak among wild birds in Russia in 2010 was presented. The study was carried out using conventional methods according to the WHO recommendations. H5N1 influenza virus isolated in Siberia belonged to clade 2.