广西猪圆环病毒2型的遗传进化分析

【目的】了解广西各地当前流行的猪圆环病毒2型（PCV2）基因型差异、出现的时间、致病性及其今后流行趋势。【方法】根据GenBank中已发表的PCV2核苷酸全序列设计1对引物,从广西不同市（县）采集的猪组织样本（脾脏、肺脏、淋巴结、流产胎儿）中成功克隆获得34株PCV2 ORF2基因序列,并对其进行遗传进化分析。【结果】获得的34株PCV2中有9株ORF2基因全长为705bp,1株为696bp,其余的为702bp;经遗传进化分析,发现PCV2可以分为PCV2a、PCV2b、PCV2c、PCV2d、PCV2e5个基因型,在34株PCV2ORF2基因中,有7株属于PCV2d型,1株属于PCV2e型,25株属于PCV2b型,未发现PCV2a和PCV2c型,而新发现的GXHP-2不归属于任何一个基因型。【结论】广西目前流行的PCV2有PCV2b、PCV2d、PCV2e3个基因型,其中以PCV2b为主。

Analysis of genetic variations in porcine circovirus type 2 strains in Guangxi

【Objective】The present experiment was conducted to study the time of occurrence, pathogenicity, future epidemic trends and genotypic differences amongst porcine circovirus type 2 （PCV2） from different regions of Guangxi. 【Method】A pair of primer was designed according to the PCV2 sequence, obtained from GenBank, to clone the ORF2 gene sequence of PCV2 in 34 isolates, which were obtained from the porcine samples of lung, kidney, lymphnodes and aborted fetus in different regions of Guangxi. 【Result】Out of 34 strains, the full-length sequence of ORF2 gene in 9 strains was 705 bp, one of them was 696 bp and the others were 702 bp. Phylogenetic analysis of the complete genome and ORF2 gene indicated that PCV2 strains could be divided into five genotypes viz., PCV2a, PCV2b, PCV2c, PCV2d and PCV2e. Of the 34 isolates, 7 belonged to PCV2d, one belonged to PCV2e, and the other 25 belonged to PCV2b. The PCV2a and PCV2c genotypes were not found. The new GXHP-2 sequence formed a branch in the phylogenetic tree alone. 【Conclustion】 The results revealed that PCV2b, PCV2d and PCV2e were the epidemic genotypes of PCV2 in Guangxi, of which, the most common was PCV2b.