A Recombinant Porcine Epidemic Diarrhea Virus with Multiple S2 Subunit Mutations from China: Isolation, Genetic...

Area of Science:

• Veterinary Virology
• Molecular Epidemiology
• Swine Disease Research

Background:

• Porcine epidemic diarrhea virus (PEDV) causes significant economic losses in the swine industry due to fatal diarrhea in piglets.
• Emerging PEDV variants, resulting from mutation and recombination, represent a continuous global threat.
• Ongoing surveillance of PEDV evolution is crucial for disease management.

Purpose of the Study:

• To isolate and characterize a novel PEDV strain, PEDV/FJLY202201, from China.
• To analyze the genetic makeup, evolutionary history, and virulence of the novel PEDV strain.
• To understand the complex evolution and molecular pathogenesis of PEDV.

Main Methods:

• Isolation and complete genome sequencing of a novel PEDV strain.
• Phylogenetic and recombination analyses to determine genetic origins and structure.
• Virulence assessment through experimental challenge in 3-day-old piglets.

Main Results:

• PEDV/FJLY202201 was identified as a recombinant strain with two recombination events between G2a and G2b strains.
• Three breakpoints were located in ORF1b, Domain 0 (D0), and the S2 subunit, with notable mutations in the S2 subunit.
• Experimental challenge resulted in severe diarrhea, 30.35% weight loss, and 100% mortality in piglets.

Conclusions:

• PEDV/FJLY202201 exhibits high virulence and complex genetic evolution.
• The identified mutations in the S2 subunit are significant and warrant further investigation.
• This study provides insights into PEDV genetic evolution and pathogenesis, aiding future surveillance and control strategies.