Genetic Variation and Pathogenic Distinctions of Porcine Epidemic Diarrhea Virus GII a and GII c subtype

Pathogenicity assays in suckling piglets demonstrated that both strains induced typical PED symptoms; however, the CH/GZ/2024 strain exhibited enhanced pathogenicity, characterized by an earlier onset of diarrhea, higher mortality rates, and more severe intestinal lesions compared to the CH/SX/2025 strain. Conversely, the CH/SX/2025 strain displayed increased tissue tropismand induced a robust interferon immune response, which we speculated may be associated with the glycosylation site mutation in the S1 protein of the CH/SX/2025 strain.

In conclusion, two different PEDV subtypes were successfully isolated from diseased newborn piglets, and their pathogenic differences were clarified. This study provides experimental basis for molecular epidemiological monitoring of PEDV and the optimization of prevention and control strategies.