安徽省部分地区2016–2018年猪圆环病毒2型遗传进化分析

Genetic evolution of porcine circovirus 2 strains in Anhui province during 2016−2018

摘要:

【背景】猪圆环病毒(Porcine circovirus，PCV)可以引起断奶仔猪多系统衰竭综合症(Postweaning multisystemic wasting syndrome，PMWS)。【目的】了解安徽省部分地区猪圆环病毒2型(PCV2)的遗传变异情况。【方法】采用PCR技术，对2016?2018年间安徽省部分地区猪场疑似PMWS感染的组织样品共计31份进行PCV2检测和全基因扩增，并通过DNAStar等生物信息学软件对所得到的PCV2毒株基因序列进行遗传进化分析。【结果】所得的8株PCV2安徽株与GenBank上已发表的国内外参考毒株相比较，核苷酸相似性为92.8%?99.0%，ORF2及其推导的氨基酸序列相似性分别为85.8%?99.6%和82.5%?100%。遗传进化树分析结果显示8株安徽株中有1株PCV2a，2株PCV2b，5株PCV2d，未发现PCV2c、PCV2e和PCV2f基因型。此外，通过对ORF2基因编码的氨基酸序列分析，发现各基因型Cap蛋白氨基酸序列上的位点具有其独特性。【结论】近年来PCV2在安徽地区的猪群中感染较为普遍，其中PCV2d基因型的感染病例增多，逐渐成为安徽地区的优势流行株。本研究为安徽地区的PCV2防控提供了一定的参考依据。

Abstract:

[Background] Porcine circovirus can cause postweaning multisystemic wasting syndrome. [Objective] To understand the epidemiology and genetic variation of porcine circovirus 2 (PCV2) in Anhui province. [Methods] Total 31 tissue samples of pig suspected suffering PMWS were collected. PCR was employed to identify PCV2 and its genome. genetic evolution of the PCV2 virus strains were analyzed by DNAStar and other bioinformatics software. [Results] Nucleotide comparability of identified 8 strains with the strains published on GenBank was 92.8%?99.0%. The comparability of ORF2 and its derived amino acid sequences was 85.8%?99.6% and 82.5%?100%, respectively. The results of genetic evolution showed that there were one strain of PCV2a, two strains of PCV2b and five strains of PCV2d among the eight strains. Moreover, there were no genotypes of PCV2c, PCV2e and PCV2f. In addition, through the analysis of amino acid sequence, unique site was found on Cap protein with each genotype. [Conclusion] PCV2 infection in pigs was common in Anhui province. PCV2d was the dominant genotype. This study provides a basis for PCV2 prevention and control in Anhui province.