Genetic variation of the VP1 gene of the virulent duck hepatitis A virus type 1 (DHAV-1) isolates in Shandong province of China.
To investigate the relationship of the variation of virulence and the external capsid proteins of the pandemic duck hepatitis A virus type 1 (DHAV-1) isolates, the virulence, cross neutralization assays and the complete sequence of the virion protein 1 (VP1) gene of nine virulent DHAV-1 strains, which were isolated from infected ducklings with clinical symptoms in Shandong province of China in 2007-2008, were tested. The fifth generation duck embryo allantoic liquids of the 9 isolates were tested on 12-day-old duck embryos and on 7-day-old ducklings for the median embryonal lethal doses (ELD(50)s) and the median lethal doses (LD(50)s), respectively. The results showed that the ELD(50)s of embryonic duck eggs of the 9 DHAV-1 isolates were between 1.9 × 10(6)/mL to 1.44 × 10(7)/mL, while the LD(50)s were 2.39 × 10(5)/mL to 6.15 × 10(6)/mL. Cross-neutralization tests revealed that the 9 DHAV-1 isolates were completely neutralized by the standard serum and the hyperimmune sera against the 9 DHAV-1 isolates, respectively. Compared with other virulent, moderate virulent, attenuated vaccine and mild strains, the VP1 genes of the 9 strains shared 89.8%-99.7% similarity at the nucleotide level and 92.4%-99.6% at amino acid level with other DHAV-1 strains. There were three hypervariable regions at the C-terminus (aa 158-160, 180-193 and 205-219) and other variable points in VP1 protein, but which didn't cause virulence of DHAV-1 change.
College of Veterinary Medicine, Shandong Agricultural University, Taian, 271018, Shandong, China.
Jiming
J
Gao
Junhao
J
Chen
Xingkui
X
Si
Zhijing
Z
Xie
Yanli
Y
Zhu
Xingxiao
X
Zhang
Shujing
S
Wang
Shijin
S
Jiang
D000595:Amino Acid Sequence; D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D001715:Bird Diseases / Q000473:pathology / Q000821:virology; D002681:China; D003429:Cross Reactions; D004372:Ducks; D014644:Genetic Variation; D006506:Hepatitis A / Q000473:pathology / Q000662:veterinary / Q000821:virology; D035922:Hepatitis A Antibodies / Q000097:blood; D007928:Lethal Dose 50; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D010849:Picornaviridae / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D016019:Survival Analysis; D015678:Viral Structural Proteins / Q000235:genetics*; D014774:Virulence
D057134:Antibodies, Neutralizing; D035922:Hepatitis A Antibodies; D015678:Viral Structural Proteins