水貂犬瘟热病毒分离鉴定及其H基因序列分析

Isolation and Identification of Canine Distemper Virus in Minks and Sequence Analysis of H Gene

为了解山东地区水貂犬瘟热病毒(CDV)遗传变异特征,采集水貂养殖场的发病水貂病料,通过RT-PCR鉴定为CDV阳性,将阳性病料接种Vero/Dog SLAM细胞进行病毒分离,通过间接免疫荧光、电镜负染、测序等方法鉴定,得到4株犬瘟热病毒,分别命名为WD1株、WD2株、WX1株和WX2株。分离株H基因测序结果显示,WD1株、WD2株、WX1株均为Asia-Ⅰ型,其中WD1和WD2与近几年仅在水貂和狐狸养殖场流行的新犬瘟热毒株核苷酸和氨基酸序列同源性分别为97.5%~99.2%和97%~99%;WX-1型与国内犬源HL001株的同源性最高,核苷酸和氨基酸序列同源性分别为99.6%和99.5%;WX2与疫苗株同属于一个分支,与疫苗毒Lederle株核苷酸和氨基酸序列同源性高达99.5%和98.8%。结果表明,水貂养殖场存在多株犬瘟热病毒混合感染的情况,提醒养殖场应注意防控,该结果也为犬瘟热病毒分子流行病学积累了资料。

To understand the genetic variation characteristics of canine distemper virus of mink in Shandong province,the samples of minks suspected infected with CDV were collected in fur animal farms.The samples were diagnosed with canine distemper virus positive by RT-PCR.And then were cultured in Vero/Dog SLAM cells.Four strains of CDV were isolated,and were named as WD1,WD2,WX1,WX2,respectively.Sequence analysis of the CDV H gene showed that the isolation strains WD1,WD2 and WX1 were grouped in the Asia-1 genotype.The strains of WD1 and WD2 shared identities ranging from 97.5 % to 99.2% at the nucleotide level and 97% to 99% at the amino acid level with the CDV strains which being spread in mink and fox farms recently.The strain WX1 shared the highest similarity with the strain HL001 which was isolated from dog,it displayed 99.6% nt identity and 99.5% aa identity.The strain WX2 was grouped in the vaccine strain,and it displayed 99.5% nt identity and 98.8% aa identity with the vaccine strain Lederle.This study showed that the minks were mixed with infections of different CDV strains in mink farms,which remind the farm to pay attention to the prevention and control and accumulate data for the research of the molecular epidemiology of the canine distemper virus.