Fig. 3.

Clinical symptoms, necropsy examinations, histopathology and IHC of the small intestines of piglets inoculated with P6 of the PDCoV strain CH/XJYN/2016 (10^4.0 TCID₅₀/mL). (a) The infected pigs had severe diarrhea; (b) Necropsy examinations of the CH/ XJYN /2016-infected piglets. Severe hyperemia, swelling and transparency were present in the intestinal tissues, especially in the small intestine. (c-d) HE-stained tissue jejunum sections from CH/XJYN/2016-infected piglets (100 × magnification); (c) Severe villous ablation was observed in the infected piglets; (d) Severe villous atrophy and fusion, degeneration and necrosis of mucosal epithelial cells were observed in the infected piglets; (f-g) Detection of PDCoV antigen by IHC analysis of small intestine sections from CH/XJYN/2016-infected piglets (400 × magnification). PDCoV antigen signals appeared brown and were detected in jejunal epithelial cell samples from CH/XJYN/2016-infected piglets; (e) The normalvillous epithelium of the jejunum from mock control piglets; (h) No PEDV antigen was detected in jejunum from mock control piglets.