Identification of natural recombinants derived from PCV2a and PCV2b

Area of Science:

• Veterinary Virology
• Molecular Epidemiology

Background:

• Porcine circovirus type 2 (PCV2) is a primary cause of significant economic losses in the global swine industry due to associated diseases.
• PCV2 exhibits continuous evolution through genetic mutation and recombination, necessitating ongoing surveillance for novel strains.

Purpose of the Study:

• To identify and characterize recombinant Porcine circovirus type 2 (PCV2) strains circulating in Guangdong Province, China.
• To elucidate the genetic mechanisms and origins of identified PCV2 recombinants.

Main Methods:

• Polymerase chain reaction (PCR) was used to detect PCV2 in suspected porcine samples.
• Full-genome sequencing, phylogenetic analysis, and sequence alignment were performed on confirmed PCV2-positive samples.
• Gene recombination analysis was conducted to identify inter-genotypic recombination events.

Main Results:

• Three novel recombinant PCV2 strains (GD003, GD005, GD008) were identified, originating from recombination between PCV2a and PCV2b strains.
• Recombination events were localized to the ORF2 region, which encodes the major structural protein.
• The identified recombinants shared a common inter-genotypic recombination pattern with a breakpoint in the structural protein gene.

Conclusions:

• This study demonstrates a specific inter-genotypic recombination pattern in PCV2 strains, highlighting the evolutionary dynamics of the virus.
• Understanding these recombination mechanisms provides crucial insights into PCV2 pathogenesis.
• The findings offer valuable data for developing effective strategies for PCV2 prevention and control in the swine industry.