鸭肝炎病毒的分离与鉴定

1999-2008年从山东、河南、浙江、江苏、广西、山西、江西、广东、福建和辽宁等地有典型鸭病毒性肝炎症状的病死雏鸭中共分离得到22株病毒。用鸭肝炎病毒（DHV）Ⅰ型（DHV-1）抗血清和新型DHV （N-DHV）抗血清对分离的22株病毒进行血清中和试验；对22株病毒的抗原相关VP1基因进行RT-PCR扩增和测序，然后对VP1基因的核苷酸与推导的氨基酸序列进行分析。结果表明，目前我国存在DHV-1和N-DHV两种血清型。其中分离到的12株为DHV-1，10株为N-DHV。依据VP1基因序列同源性进行的血清型分型结果与根据抗原性鉴定进行的血清型分型结果一致。12株DHV-1的氨基酸序列同源性为95%左右，10株N-DHV的氨基酸同源性为98%左右；DHV-1分离株与N-DHV分离株间氨基酸同源性为72%-77%。同血清型病毒株间的VP1基因变异很小，表明DHV的抗原性稳定。

Isolation and Identiifcation of Duck Hepatitis Virus

22 strains of duck hepatitis virus（DHV） were isolated from sick or died ducks with typical symptoms of duck hepatitis in Shandong,Henan,Zhejiang,Jiangsu,Guangxi,Shanxi,Jiangxi,Guangdong,Fujian and Lia-oning Provinces from 1999 to 2008. Serum neutralization test were conducted using duck hepatitis virus I type（DHV-1） antiserum and the new DHV（N-DHV） antiserum with these 22 strains. The VP1 genes of the isolated strains were amplified using RT-PCR and then sequenced. Amino acid sequences of VP1 were then deduced and analyzed. The results showed that there were two serotypes of DHV in China. Among the 22 strains,12 strains were in DHV-1 and 10 strains in N-DHV. The serotyping result based on the homology of VP1 gene sequences was identical to the result based on the antigenicity serotyping. Amino acid sequence homology was 95% within 12 DHV-1 strains and 98% within 10 N-DHV strains respectively. The amino acid homology of VP1 gene was 72-77% between DHV-1 and N-DHV strains. The less variation of VP1 gene in the same serotype strains suggested that the antigenicity of DHV was stable.