Percentage survival of chickens after inoculation with SD09 or GD09-2 velogenic NDVs.

<p>Percentage survival of chickens after inoculation with SD09 or GD09-2 velogenic NDVs.</p

Histopathology on tissues from 1-week-old chickens infected with NDV GD09-2 or SD09 (H&E).

<p>B and C: amalgamation of collapsed cell and inflammatory exudates created the homogeneous and pink-staining appearance in the white pulps of spleens (black arrow); E and F: dropout and necrosis of the mucosal epithelia in the proventriculus (black arrow); H and I: dropout of epithelium and numerous inflammatory cell infiltration in the small intestine (black arrow); K and L: congestion (black arrow) or glomerulus atrophy (white arrow) in the kidneys; N and O: dropout and necrosis of mucous epithelial cells in the trachea (black arrow); Q and R: congestion and hemorrhage in the lung (black arrow); T and U: venous congestion in the cerebrum (black arrow); W and X: venous congestion in the cerebellum (black arrow); A, D, G, J, M, P, S and V: Corresponding control tissues. Scale bar = 50 µm in cerebellum or 100 µm in other tissues.</p

NDV strains and their accession numbers used for phylogenetic analysis.

<p>NDV strains and their accession numbers used for phylogenetic analysis.</p

Phylogenetic tree based on the nucleotide sequences of the fusion gene (A) (nt 1–1662) and hemagglutinin-neuraminidase gene (B) (nt 1–1713 or 1731) of NDV.

<p>The phylogenetic tree was constructed by the Neighbor-Joining method with 1000 bootstrap replicates (bootstrap values are shown on the tree).</p

Histopathology on tissues from 1-week-old ducks infected with NDV GD09-2 or SD09 (H&E).

<p>B and C: hemorrhage (group GD09-2, black arrow) or degeneration of renal tubules epithelial cells (group SD09, black arrow) and eosinophil infiltration (group SD09, white arrow) in the kidneys; E and F: necrosis and disappear of lymphocyte (black arrow) or coagulation necrosis of massive tissue (white arrow) in the spleens; H and I: villus missing (white arrow) and necrosis of epithelial cell infiltration (black arrow) in the small intestines; K and L: dilatation of hepatic sinus and thrombus (group GD09-2, black arrow), lymphocyte infiltration (group GD09-2, white arrow), dilatation of hepatic sinus (group SD09, black arrow) and venous congestion (group SD09, white arrow) in the livers. A, D, G and J: Corresponding control tissues. A–I: scale bar = 100 µm, J–L: scale bar = 50 µm.</p

Primers used in the study.

<p>Primers used in the study.</p

Details of the two NDV isolates investigated in this study.

a<p>Mean death time in embryonating eggs (hours) (<60: velogen; 60–90: mesogen; >90: lentogen).</p>b<p>Intracerebral pathogenicity index in day-old chicks (1.5–2.0: velogen; 1.0–1.5: mesogen; <0.5: lentogen).</p

Percentage survival (A) and sero-conversion at 14 dpi (B) of ducks after inoculation with SD09 or GD09-2 velogenic NDVs.

<p>Percentage survival (A) and sero-conversion at 14 dpi (B) of ducks after inoculation with SD09 or GD09-2 velogenic NDVs.</p

Immunohistochemical detection of NDV antigens in liver after experimental infection with NDV GD09-2.

<p>B: Viral antigen was detected extensively in the liver cells (black arrow). A: Corresponding control tissues. Scale bar = 50 µm.</p

Virus shedding from ducks by the cloacal route following inoculation with GD09-2 virus.

a<p>By reverse transcriptase-polymerase chain reaction.</p