2株PEDV分离株在仔猪体内致病性差异OA

Porcine epidemic diarrhoea virus(PEDV)is one of the major pathogens threatening the health and productivity of pig farms.Continuous viral mutation has led to a significant decline in the protective efficacy of traditional vaccines based on the CV777 strain.To compare the differences in pathogenicity between different PEDV strains in piglets,using 1-day-old piglets as an infection model,techniques such as haematoxylin and eosin(HE)staining,indirect immunofluorescence,RT-qPCR,and Western blot were employed to compare the pathogenicity differences of the GroupⅠ strain CH/QD/2018(PEDV-QD)and the Group Ⅱ variant strain LJX01/2014(PEDV-LZ)in piglets.The results indicated that,compared with the PEDV-QD group,piglets in the PEDV-LZ group exhibited more severe clinical diarrhoea symptoms and more pronounced pathological changes in the duodenum,jejunum and ileum;indirect immunofluorescence results showed that the relative fluorescence intensity in the duodenum of the PEDV-LZ group was significantly higher than that of the PEDV-QD group;Virus copy number detection in anal swab and intestinal content samples indicated that PEDV-LZ replicated more rapidly,with the most severe infection observed in ileal tissue;Western blot results showed that PEDV-N protein expression was higher in the ileal tissue of piglets in the PEDV-LZ group,suggesting that PEDV-LZ possesses greater infectivity.This study provides a reference for further elucidating the differences in pathogenicity between the two PEDV strains and for formulating effective prevention and control strategies.