北京市猪场猪圆环病毒3型感染状况调查及其ORF2基因遗传进化分析

Investigation on the Infection Status of Porcine Circovirus Type 3 in Beijing and Phylogenetic Analysis of ORF2 Gene

Key words:  Porcine circovirus type 3  PCR detection  ORF2 gene  phylogenetical analysis

摘要:

为了了解猪圆环病毒3型(PCV3)在北京市不同区县猪场中的流行情况,本研究建立PCR检测方法,对来自北京市8个区县56个养殖场的1177份临床样品进行检测,并对获得的部分ORF2全基因序列进行遗传进化分析。结果显示,PCV3总体阳性率1.0%(12/1177),场阳性率为8.9% (5/56)。对PCV3阳性样本进行ORF2基因测序及同源性比对,共测得12株PCV3 ORF2全长基因序列,其中包括6株不同的ORF2全长基因序列。结果显示,该6株序列之间的核苷酸相似性为97.7%-99.5%之间；推导氨基酸序列的相似性为97.2%-100%之间。与参考毒株之间的核苷酸同源性为96.0%-99.5%,推导氨基酸同源性为92.1%-100.0%,进化树显示北京毒株属于PCV3b基因型。表明PCV3在北京多个猪场呈现一定的流行趋势,流行毒株以PCV3b基因型为主,有必要进一步开展北京地区PCV3的流行病学调查。

Abstract:

For understanding of porcine circovirus virus type 3(PCV3) prevalence of pigs in Beijing, A total of 1177 clinical samples from 56 farms in 8 districts and counties of Beijing were collected and detected by PCR metheod established, and part of the strain of the ORF2 gene sequence analysis of genetic evolution. The results showed that the overall positive rate of PCV3 was 1.0%(12/1177) and the field positive rate was 8.9%(5/56). The ORF2 gene sequencing and homology alignment were performed on PCV3 positive samples, while six different PCV3 ORF2 full-length gene sequences were detected. The results showed that the nucleotide similarity between the six sequences was in 97.7%-99.5%; while the deduced amino acid sequence similarity was in 97.2%-100%. Compared with reference strains, the homology was 96.0%-99.5%, while the deduced amino acid homology was 92.1%-100.0%. The phylogenetic tree showed that the Beijing strains belonged to PCV3b genotype. The result indicated that PCV3 had a certain epidemic trend in Beijing pig farms, and the prevalent strains were mainly of PCV3b genotype. Therefore, it was necessary to further conduct epidemiological investigation of PCV3 in Beijing.