猪圆环病毒2型田间分离株的全基因组克隆与基因亚型分析

Cloning and Sequence Analysis of the Complete Genome of Porcine Circovirus Type 2 Isolate

关键词:  猪圆环病毒2型  全基因组  序列分析

Key words:  Key words: porcine circovirus type 2  complete genome  sequence analysis

摘要:

为了解我国猪圆环病毒2型（PCV2）的流行态势和毒株的基因变异情况，从北京、江苏、湖北等地疑似断奶仔猪多系统综合征（PMWS）患病死亡猪中采集肺脏、脾脏和淋巴结等组织，将PCR鉴定为阳性的病料在PK-15细胞上进行增殖培养，成功分离到6株猪圆环病毒2型毒株，分别命名为B07、B12、HB、LHW、LPC和NJ。对其全基因组进行克隆和序列分析的结果显示，LPC基因组全长为1766 bp，其余均为1767 bp；6个毒株序列之间同源性高达96.0%~99.9%，6个毒株与参考毒株序列的同源性为94.4%~99.8%。PCV2全基因组的进化分析结果表明，B12、HB、LHW、LPC和NJ为PCV2b亚型，B07为PCV2d亚型，从而证实PCV2b亚型毒株成为我国猪群中分离率较高的流行毒株，并且我国猪群存在PCV2d亚型毒株。

Abstract:

To understand the prevalent trend and genetic variations of procine circovirus type 2 (PCV2) in our country, lungs, spleens and lymphonodi associated with postweaning multisystemic wasting syndrome(PMWS) were collected from Beijing, Jiangsu and Hubei province, and the disease materials that proved to be positive by polymerase chain reaction(PCR) were cultured in PK-15 cells. Six PCV2 strains were successfully isolated and marked as B07, B12, HB, LHW, LPC and NJ, respectively. The complete genome of 6 isolated strains was cloned, sequenced and analyzed. Results showed that the full length of genomic sequence of LPC was 1766 bp, while the others were 1767 bp. The 6 isolated strains showed high identity with each other(96%～99.9%) and the identity between 6 isolated strains and the reference viruses was 94.4%～99.8%. Phylogenetic analysis demonstrated the isolated strains B12, HB, LHW, LPC and NJ were classified into PCV2b genotype, B07 was classified into PCV2d genotype. In conclusion, PCV2b group strain was predominant prevailing strain and the pig farms had PCV2d group strain infection.