川东北地区腹泻牛群中牛病毒性腹泻病毒的分子流行病学调查及病毒分离鉴定

Molecular Epidemiological Investigation and Virus Isolation and Identification of Bovine Viral Diarrhea Virus in Diarrhea Cattle in Northeast Sichuan

为了掌握川东北地区腹泻牛群中牛病毒性腹泻病毒(BVDV)的感染情况和主要流行基因型及亚型,采用RT-PCR方法对采集于川东北地区临床腹泻牛粪便样品进行了病原学检测。根据5'-UTR基因序列进行遗传变异分析和基因分型鉴定,并对RT-PCR阳性样品进行了病毒的分离鉴定。结果显示:97份腹泻样品中BVDV平均阳性感染率为9.28%,达州市的阳性率最高(13.04%)、巴中市的阳性率最低(5.26%)。在5'-UTR基因系统进化树中9份阳性样品均为BVDV-1型,包括BVDV-1a(n=2)和BVDV-1b(n=7),经细胞培养、RT-PCR检测、间接免疫荧光检测共分离鉴定出2株致细胞病变型BVDV。表明川东北地区腹泻牛群中均存在BVDV感染,流行的优势基因亚型为BVDV-1b,丰富了BVDV的分子流行病学资料,为川东北地区BVDV的综合防控提供了理论基础。

In order to grasp the infection status and main prevalent gene subtypes of bovine viral diarrhea virus(BVDV)in diarrhea cattle in Northeast Sichuan,RT-PCR was used to detect the etiology of fecal samples of clinical diarrhea cattle collected in Northeast Sichuan,and the genetic variation analysis and genotyping were carried out according to the 5'-UTR gene sequence.The results showed that the average positive rate of BVDV was 9.28%in 97 fecal samples of diarrhea,with Dazhou city the highest positive rate(13.04%)and Bazhong city the lowest positive rate(5.26%).In the phylogenetic tree of 5'-UTR gene,9 positive samples were BVDV-1,including BVDV-1a(n=2)and BVDV-1b(n=7),two cytopathic BVDV strains were isolated and identified by cell culture,RT-PCR and indirect immunofluorescence.The results showed that there is BVDV infection in diarrhea cattle in Northeast Sichuan,and the dominant genotype is BVDV-1b,which enriched the molecular epidemiological data of BVDV and provided a theoretical basis for the comprehensive prevention and control of BVDV in Northeast Sichuan.