Molecular characterization and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field isolates in Korea

Porcine epidemic diarrhea virus (PEDV) has caused enteric disease with devastating impact since the first identification of PEDV in 1992 in Korea. In this study, we investigated molecular epidemiology, showed genetic diversity, and analyzed phylogenetic relationships of Korean PEDV field isolates with other PEDV reference strains. Genetic analysis of the complete M and ORF3 genes showed that each PEDV group had several unique characteristics, and this indicated that specific groups of PEDVs may be differentiated from the other PEDVs by specific nucleotide differences. Especially, ORF3 gene analysis can be used for discrimination between vaccine and wild-type PEDVs. Sequence and phylogenetic analysis showed that recent, prevalent Korean PEDV field isolates have close relationships to Chinese field strains and differ genetically from European strains and vaccine strains used in Korea. These results raise questions as to whether a new type of PEDV vaccine may be necessary for preventing PEDV infection more effectively in Korea.