广西壮族自治区猪圆环病毒2型(PCV2)分子流行病学调查及遗传变异分析OACSTPCD

[Objective]This study was conducted to understand the prevalence and genetic characteristics of porcine circovirus type 2(PCV2)in Guangxi Zhuang Autonomous Region.[Method]The clinical samples collected from different areas of Guangxi Zhuang Autonomous Region were subjected to PCV2 detection and whole genome sequence amplification by PCR assay.The bioinformatics software including BioEdit,Mega 7.0,RDP 5 and SimPlot(ver 3.5.1)were used to perform nucleotide sequence similarity,genetic variation and recombination analyses on the while genome sequences of 24 PCV2 strains obtained.In addition,the variation sites on amino acid sequences of the Cap protein were analyzed.[Result]The genomic size of the PCV2 Guangxi strains were all 1 768 bp.Nucleotide sequence similarity analysis showed that the PCV2 Guangxi strains shared 44.7%to 99.7%similarity with the referential strains PCV1-PCV4,and had the lowest similarity with PCV3.The PCV2 Guangxi strains were determined as PCV2b and PCV2d subtypes,with PCV2d being the most prevalent.Whole genome sequence recombination analysis demonstrated that there were recombination events in selected PCV2 Guangxi strains.In comparison with the vaccine strains AY686764-PCV2b and HM641752-PCV2b,a total of 21 variation sites were observed on the amino acid sequences of the Cap protein of the PCV2 Guangxi strains.[Conclusion]PCV2d was the dominant subtype of the PCV2 Guangxi strains.Several strains had genomic recombination events and unique amino acid variations on some loci,indicating a clear genetic evolution trend.The research results provided basic data for the epidemiological investigation and genetic evolution analysis of PCV2 in Guangxi Zhuang Autonomous Region.