Skip to main content
[Preprint]. 2021 Dec 29:rs.3.rs-1211792. [Version 1] doi: 10.21203/rs.3.rs-1211792/v1

Figure 3. Pathological findings in the lungs of SARS-CoV-2 infected Syrian hamsters.

Figure 3

The hamsters were infected with B.1.617.2 or B.1.1.529 variant of SARS-CoV-2 and sacrificed on 3 days (n = 4) and 6 days (n = 4) post infection for histopathological examinations. a, Macroscopic images of the lungs obtained from B.1.617.2 or B.1.1.529-infected Syrian hamsters at 6 dpi. Yellow arrows indicate areas of pulmonary hemorrhage. b, Representative histopathological images for the lung sections obtained from the animals infected with B.1.617.2 or B.1.1.529 at 3 or 6 dpi are shown at low magnification. Scale bars, 200 μm. Focal alveolar hemorrhage found in B.1.617.2-infected animals at 6 dpi is highlighted by dashed lines and shown at higher magnification in the inset image (scale bar indicating 100 μm). c, Histopathological score of viral pneumonia in the lungs of infected hamsters. Score was determined based on the percentage of alveolitis in a given section collected from each animal in each group using the following scoring: 0, no pathological change; 1, affected area (≤10%); 2, affected area (<50%, >10%); 3, affected area (≥50%); an additional point was added when pulmonary edema and/or alveolar hemorrhage was observed. Data are expressed as scatter plots with the median score ± 95% confidential interval. Each dot represents the score of each animal. Comparison between B.1.617.2 (n = 4) or B.1.1.529 (n = 4) was performed using Kruskal-Wallis test with a Dunn’s post-tests. ns, not significant; *, P < 0.05. d, RNA in situ hybridization (RNA-ISH) for SARS-CoV-2 viral RNA. Representative RNA-ISH images for the alveoli and bronchi of hamsters infected with B.1.617.2 (n = 4) or B.1.1.529 (n = 4) virus at 3 or 6 dpi are shown. Left panels, alveolar region. Right panels, bronchial region. Scale bars, 20 μm.