凉山州腹泻仔猪猪圆环病毒2型感染情况调查

Investigation on the Infection Situation of Porcine Circovirus Type 2 in Diarrhea Piglets in Liangshan

Key words:  Porcine circovirus type 2  ORF2  PCR  Liangshan prefecture

摘要:

为了解凉山州腹泻仔猪猪圆环病毒2型(PCV2)的感染情况,采用PCR方法对采自四川省凉山州西昌市和喜德县7个猪场85份腹泻仔猪粪便、病变组织等样品进行PCV2检测,并将扩增到的PCV2 ORF2基因片段进行测序和序列分析。结果显示,PCV2阳性样品有22份,阳性率为25.9 %,阳性猪场占71.4 %(5/7)。22个ORF2基因片段长度均为459 bp,核苷酸同源性为92.8 % ~ 100 %,氨基酸同源性为93.5 % ~ 100 %。构建的系统进化树显示22个测序序列分别处于2个分支：PCV2b和PCV2d,但未形成明显的地理分支。结果表明凉山州猪群中PCV2感染较为普遍,且以PCV2d亚型为主,并存在一定程度的遗传变异。

Abstract:

In order to know the infection of porcine circovirus type 2 (PCV2) in diarrhea piglets in Liangshan prefecture, a total of 85 samples including feces of diarrhea piglets and pathological tissues from 7 pig farms in Xichang city and Xide county, Liangshan prefecture, Sichuan province were used to detect ORF2 gene of PCV2 by PCR and sequenced. The results showed that 22 samples were PCV2 positive detected by PCR, the positive rate was 25.9 %, and positive farms was 71.4 % (5/7). The lengths of 22 isolates were 459 bp, the nucleotide sequence homologies of ORF2 gene were 92.8 % ~ 100 %, and the amino acid homologies were 93.5 % ~ 100 %. The phylogenetic tree showed that these 22 PCV2 strains isolated from Liangshan belonged to two subtypes: PCV2b and PCV2d, with not formed obvious geographical branch. This study indicated that the epidemic situation of PCV2 in Liangshan was common, PCV2d may be the dominant genotype in Liangshan and certain genetic variation was presented.