宁夏地区犬细小病毒的分离鉴定及其VP2基因进化分析

Isolation and Identification of the Canine Parvovirus and Evolution Analyses of the VP2 Gene in Ningxia Hui Autonomous Region,China

犬细小病毒(Canine parvovirus,CPV)具有高度传染性,是幼犬最危险的消化道传染病病原之一。为了解宁夏地区CPV的流行现状及其VP2基因的遗传变异情况,本研究采集了14份经胶体金试纸条检测为CPV阳性的腹泻犬粪样,进行病毒分离和鉴定,并将分离株VP2基因全序列进行克隆和测序分析。结果显示,14份样品中成功分离到5株CPV;病毒TCID50在104.9/0.1mL^105.4/0.1mL之间;HA效价均达1∶512以上;序列分析显示,5株分离株中3株为new CPV-2a型,2株为new CPV-2b型;分离株与参考株的核苷酸和氨基酸相似性分别为98.2%~99.9%和96.9%~99.8%;聚类分析显示,分离株序列全部聚类在同一分支。本研究的结果为我国西北地区CPV分离株的分子流行病学和遗传多样性提供了依据,有助于该地区预防和控制CPV感染。

The canine parvovirus(CPV)is highly infectious and is one of the most dangerous digestive tract infectious diseases in puppies. We wished to study the prevalence of the CPV and variation of the VP2 gene in Ningxia Hui Autonomous Region,China. Fourteen feces samples of diarrhea dogs with CPV positive tested by colloidal gold test strips were collected and virus isolation and identification experiments were conducted. Then we cloned and analyzed the whole gene sequence of VP2. Results showed that 5 strains of CPV were successfully isolated from 14 samples,the virus TCID50 was 104.9/0.1 mL to 105.4/0.1 mL,the HA titer were higher than 1∶512. Sequence analysis showed that among the 5 isolates,3 strains were new CPV-2 a and 2 strains were new CPV-2 b. The nucleotide and amino acid sequence similarity between isolates and reference strains were 98.2%~99.9% and 96.9%~99.8%,respectively. Cluster analysis showed that the isolates sequences were all clustered in the same cluster. These results provide a basis for understanding the molecular epidemiology and genetic diversity of CPV isolates in Northwest China. Our data could contribute to the prevention and control of CPV infection in this area.