Epidemiological Investigation of Duck Hepatitis A Virus (DHAV)
Isolated from Sichuan Basin by RT-PCR Disclose the Existence of
Mixed Infection and the Feasibility of DHAV-A Evolved from C80
Strain
1Rongchang Campus,
Southwest University, China 402460; 2Chongqing University
of Science and Technology, 401331, China. *Corresponding author: chhuang2007@sinano.ac.cn (HC); jixainglucky@126.com
(LJ)
Abstract
Thirty-five DHAV field isolates from suspected
ducklings in Sichuan Basin in 2002-2010 were RT-PCR confirmed by sequencing their VP1 gene.
Results demonstrated that DHAV-A (22) and DHAV-C (13) were dominant types.
Furthermore, DHAV-A, DHAV-C infection and their co-infection
still exists to some degrees. Gene analysis of VP1 disclosed that there are not
obvious differences in nucleotides similarity and amino acid mutation except the V160
and G/N/D187 for reference strain was changed as G160 and
S187 for DHAV-A field strains and these two amino acid sites can be
afterwards used as a beacon of molecular epidemiological investigation. Besides, all DHAV-A isolates possess nearest genetic
relationship with reference strain C80 which was also previously isolated from
China and used as vaccine strain. The
feasibility that some variant strains were evolved from C80 strain may not be excluded.
Key words:
DHV,
Molecular analysis,
RT-PCR, Virion protein 1 (VP1)