Quantification of PPR viral RNA in blood, nasal and oral swabs determined using real-time RT-PCR.

<p>Both nasal and oral swabs were collected from sheep (A) and goats (B) at various time points until 21 dpi. Viral RNA quantification from whole blood (C) was also performed at identical time points. Note that in the case of sheep (C), viral RNA was not detectable at any time point before or after experimental infection with PPRV. Results presented are the mean value with standard deviation from animals at each time point. P<0.05 for sheep and goat nasal swabs at 6, 8 and 11 dpi and for sheep and goat oral swabs at 6 and 8 dpi compared to −2 dpi by t-test. P<0.05 for goats whole blood at 4, 6 and 8 dpi compared to −2 dpi by t-test.</p

Quantification of interferon-gamma (IFN-γ) in serum samples collected from sheep and goats following PPRV infection.

<p>Measurement of IFN-γ levels were performed using an IFN-γ ELISA and cross-reactive antibodies against bovine IFN-γ, and quantified using a standard provided by the manufacturer. Results presented are the mean values with standard deviations from animals at each time point. P<0.05 for goats at 8 dpi compared to −2 dpi by t-test.</p

Rectal temperatures of sheep and goats following PPRV infection.

<p>Rectal temperatures of sheep and goats were measured 2 days prior to experimental infection with PPRV (Malig strain), and following infection at regular intervals until 21 dpi. Results presented are the mean temperatures with standard deviations from animals at each time point.</p

Histopathology and immunohistochemistry of goat lung at 8 dpi.

<p>(A) Hyperplasia of bronchiolar epithelium is evident with scattered epithelial degeneration (arrowheads) and abundant neutrophils within the lumen. Surrounding parenchyma is consolidated (*) with severe infiltration of mononuclear inflammatory cells. Note large syncytial cell (arrow). (B) Positive immunolabelling for CD68 was observed within multinucleated syncytial cells indicating they are of monocyte/macrophage origin (arrow). Note positive immunostaining of adjacent macrophages (arrowheads). (C) Positive immunolabeling for cytokeratin is observed within pneumocytes (arrowhead); however, syncytial cells are negative (arrow) indicating that they are not of epithelial origin. (D) Double immunolabelling detected the simultaneous expression of CD68 macrophage marker (brown stain, arrow) and PPRV antigen (pink stain, arrowhead) within multinucleated syncytial cells. Inset: Double immunolabelling detected expression of CD68 macrophage marker (brown stain, arrowhead) and PPRV antigen (pink stain, arrow) within the same cell indicating the presence of viral antigen within macrophages. Bar = 10 µm.</p

Seroconversion following experimental PPRV infection.

<p>PPRV-specific antibody titres in serum from sheep (A) and goats (B) measured using an indirect ELISA and virus neutralization test (VNT). Results presented are the mean values with standard deviations from animals at each time point. P<0.05 for ELISA from sheep and goats starting at 8 dpi compared to −2 dpi and P<0.05 for VNT from sheep and goats starting at 11 dpi compared to −2 dpi by t-test.</p

Real-time RT-PCR, H&E and IHC result comparison for goats euthanized on 6, 8 and 11 days post-infection.

<p>Y = Lesions present consistent with PPR infection.</p><p>N = No significant histopathological findings.</p><p>NS− No sample.</p><p>IHC = Immunohistochemistry score: +wk = weak immunostaining (<20 cells);+ = mild immunostaining (<25% of the section);++ = moderate immunostaining (25% to 50% of the section);+++ = abundant immunostaining (51% to 75% of the section);++++ = extensive immunostaining (>75% of the section).</p

Cross-section through a tonsil from a goat at 8 dpi.

<p>There is necrosis of surface epithelium and extensive neutrophilic infiltrate (*) as well as occasional syncytial cells (arrow) and intranuclear inclusion bodies in upper epithelial layers (arrowhead, see inset). HE stain, bar = 50 µm. Inset: Eosinophilic intranuclear inclusion bodies. Bar = 5 µm.</p

Real-time RT-PCR, H&E and IHC result comparison for sheep euthanized on 6, 8 and 11 days post-infection.

<p>Y = Lesions present consistent with PPR infection.</p><p>N = No significant histopathological findings.</p><p>NS− No sample.</p><p>IHC = Immunohistochemistry score: +wk = weak immunostaining (<20 cells);+ = mild immunostaining (<25% of the section);++ = moderate immunostaining (25% to 50% of the section);+++ = abundant immunostaining (51% to 75% of the section);++++ = extensive immunostaining (>75% of the section).</p