3株猪Ⅱ型圆环病毒的分离及基因组序列分析

Isolation and genomic sequence analysis of three PCV2 isolates

为了解混合感染中猪圆环病毒Ⅱ型(PCV2)毒株的遗传变异特性,本研究对2009年与高致病性猪繁殖与呼吸综合征病毒混合感染的病料中分离的3株PCV2通过PCR、免疫荧光等进行初步鉴定,并扩增病毒全基因组,用DNAStar对序列进行拼接和分析。结果表明:分离得到的HUN-09株(GQ449670)、HUB-09株(GQ449671)和SD-09株(GQ449669)3个PCV2毒株其全基因组长度均为1768bp,与国内外参考毒株核苷酸序列同源性为95%～99.7%,3个分离株之间的核苷酸序列同源性为97.6%～98.5%,与PCV1分离株核苷酸序列同源性为69%～70%。进化分析表明,本研究2009年分离的3株PCV2属于基因型PCV-2a。

Three porcine circovirus type 2 （PCV2） HUN-09 （GQ449670）, HUB-09 （GQ449671）, and SD-09 （GQ449669） were isolated from highly pathogenic porcine reproductive and respiratory syndrome virus co-infected samples. The PCV2 isolates were identified by PCR and confirmed by indirect fluorescent antibody test. The complete genomes of these PCV2 isolates were sequenced and their molecular variations analyzed using DNAStar software. Comparison analysis of the complete genomic sequences of three PCV2 isolates indicated that they were closely related to each other （97.6 % to 98.5 %） and to other PCV2 strains in GenBank （95 % to 99.7 % ）. There was 69 % to 70 % sequences identity among PCV2 and PCV1 isolates gene. Phylogenetic analysis revealed that all three isolates belonged to genotype PCV-2a.