Fig. 7.

Macroscopic and microscopic small intestine lesions in piglets from three groups. (A-C) Small intestines from representative piglets inoculated with PEDV Aram-P5 (A), -P29-CA (B), or mock (C) were examined for gross lesions. Note that only piglets inoculated with the parental virus typical thin and transparent intestinal walls (panel A). (D-F) Hematoxylin and eosin-stained tissue sections of the jejunum from representative piglets inoculated with PEDV Aram-P5 (D), -P29-CA (E), or mock (F) (100× magnification). Jejunums from piglets infected with the virulent Aram-P5 strain showed acute diffuse, severe atrophic enteritis with villous shortening (panel D). The normal villous epithelium of the jejunums was recorded in pigs inoculated with Aram-P29-CA (panel E), and a mock-inoculated piglet (panel F). (G-I) Detection of PEDV antigen by IHC analysis of jejunum tissue sections from representative piglets inoculated with PEDV Aram-P5 (G), -P29-CA (H), or mock (I) (200× magnification). PEDV antigen signals appear as brown staining and were detected in epithelial cells of the jejunums of all PEDV Aram-P5-inoculated piglets (panel G). No PEDV antigen was detected in the jejunums of piglets inoculated with Aram-P29-CA (panel H), or a mock-inoculated piglet (panel I).

PEDV, porcine epidemic diarrhea virus.