Porcine epidemic diarrhea virus (PEDV) is a major causative pathogen of a highly contagious, acute enteric viral disease. This study evaluated the emergence of nine variants in Jiangsu and Anhui provinces of China from 2020 to 2023. S gene-based phylogenetic analysis indicated that three variants belong to the G1c subgroup, while the other six strains are clustered within the G2c subgroup. Recombination analyses supported that three variants of the G1c subgroup were likely derived from recombination of parental variants FR0012014 and a donor variant AJ1102. In addition, there are novel mutations on amino acid 141–148 and these likely resulted in changes in antigenicity in the three variants. These results illustrated that the study provides novel insights into the epidemiology, evolution, and transmission of PEDV in China.

Porcine epidemic diarrhea virus (PEDV), a highly infectious alphacoronavirus, has resulted in substantial economic losses within the global swine industry. Existing vaccines and therapeutic agents have proven inadequate in effectively preventing and controlling PEDV. Natural compounds offer distinct advantages in antiviral research due to their abundant availability, diverse biological activities, and low toxicity. In this study, the antiviral properties of the naturally occurring alkaloid 1-deoxynojirimycin (DNJ) against PEDV were examined. The CC₅₀ of DNJ was determined to be 912.5 μM through experimental analysis on Vero-E6 cells. DNJ demonstrated an inhibitory effect on PEDV activity, with a 50% inhibitory concentration (IC₅₀) of 57.76 μM. The compound primarily inhibited PEDV proliferation during the viral life cycle stages of attachment and replication. Moreover, DNJ mitigated the production of reactive oxygen species (ROS) and inflammation associated with PEDV infection. Computational docking predictions suggest that the viral non-structural proteins include Nsp12, Nsp14, and Nsp16 may serve as potential targets for DNJ. Consequently, DNJ represents a promising candidate for the development of novel therapeutic agents against PEDV.