This article describes the nomenclature, history and genetic evolution of duck hepatitis A virus, and updates the epidemiology, clinical symptom and surveillances of duck virus hepatitis A. It also summarizes the present status and progress of duck virus hepatitis A and illustrated the necessity and urgency of its research, which provides rationale for the control of duck hepatitis A virus disease in China.
Animals ; Ducks ; virology ; Hepatitis Virus, Duck ; classification ; genetics ; isolation & purification ; Hepatitis, Viral, Animal ; virology ; Picornaviridae Infections ; veterinary ; virology

OBJECTIVETo clone and analyze duck hepatitis B virus genome from Chongqing brown duck.

METHODSDuck hepatitis B virus (DHBV) DNA extracted from a Chongqing brown duck was amplified by PCR and cloned into PGEM-T vector using T-A clone method. The sequence of this DHBV genome was analyzed with some softwares after identified.

RESULTSThe duck hepatitis B virus genome from Chongqing brown duck (DHBVcq), which was 3 024 nucleotides long, contained three ORFs whose onset and end nucleotides were in accord with those of HPUGA, encoding P, PreC/C and PreS/S protein respectively. Comparison of this strain with other DHBV reported in GenBank showed that the homology of DHBVcq and M32990 got the highest score of 94.9% at nucleotide level, while DHBVcq and DHBVCG got the least (89.8%). Most of the conserved regulation nucleotides and amino acids sequence found in other DHBV were also identified in DHBVcq. The epsilon region of DHBVcq, which was important for encapsidation of pgRNA and synthesis of minus-strand DNA, differed from that of most other DHBV strains, forming a stem-loop conformation with a three- nucleotides upper stem rather than a common nine-nucleotides one in free status.

CONCLUSIONThe successful clone and analysis of DHBVcq provide further studies with helpful information.

Animals ; Cloning, Molecular ; DNA, Viral ; chemistry ; genetics ; Ducks ; Hepatitis B Virus, Duck ; classification ; genetics ; Hepatitis Virus, Duck ; genetics ; Open Reading Frames ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Sequence Homology

The authentic 3' terminal sequences of genomes of duck hepatitis virus (DHV) serotype I strain C80 and serotype I variant strain E63 were obtained by using 3' RACE and RT-PCR techniques. The analysis showed that 3' terminal sequences in the genomes of the two DHV strains include the 3D region of 1359 nucleotides (nt), the terminator codon TGA, and 3'untranslated region (UTR) of 314 nt. The poly (A) tails of C80 and E63 are 18 nt and 19 nt in length respectively. The deduced 3D proteins of 453 amino acids of both DHV strains contain the motifs KDELR, DxxxxD, GxxCSGxxxTxxxNS, YGDD, and FLKR characteristic for RNA polymerase of picornaviruses, which confirms DHV serotype I to be a member of Picornaviridae . The amino acid sequence identities among 3D protein of the two DHV strains with representatives of nine other picornavirus genera range from 16% to 37%, which are within the value ranges (18%-60%) of 3D amino acid sequence identities obtained from inter-genera comparisons. In addition, DHV serotype I possesses the longest 3'UTR in the family Picornaviridae. Phylogenetic analysis of 3D proteins indicated that DHV serotype I may belong to a separated genus of the family Picornaviridae.
3' Untranslated Regions ; genetics ; Amino Acid Sequence ; Animals ; Base Sequence ; Cloning, Molecular ; Ducks ; Genome, Viral ; Hepatitis Virus, Duck ; classification ; genetics ; Molecular Sequence Data ; Phylogeny ; Sequence Alignment

Duck hepatitis B virus (DHBV) belongs to the Avihepadnavirus genus of the Hepadnaviridae, and it not only has the same replication pattern, but also has the similar genomic and antigenic structures to Hepatitis B virus (HBV). The genome of DHBV is a partially double-stranded closed circular DNA. The genome consists of three distinct open reading frames (ORFs): ORF-PreS/S, ORF-PreC/C and ORF-P, which all locate on the negative DNA strand and encode four separate proteins. The ORF-PreS/S encodes envelope proteins L and S, and the ORF-PreC/C and ORF-P encode capsid proteins C and polymerase proteins P, respectively. The characteristics of genome structure,viral proteins features and functions were described in this review in order to provide useful information for the further study of DHBV and the duck model infected by DHBV.
Animals ; Ducks ; Hepadnaviridae Infections ; veterinary ; virology ; Hepatitis B Virus, Duck ; chemistry ; genetics ; isolation & purification ; Hepatitis, Viral, Animal ; virology ; Open Reading Frames ; Protein Structure, Tertiary ; Viral Proteins ; chemistry ; genetics

Animals ; DNA, Viral ; genetics ; isolation & purification ; Ducks ; Hepatitis B Virus, Duck ; genetics ; isolation & purification ; Hepatitis, Viral, Animal ; virology ; Organic Chemicals ; Polymerase Chain Reaction ; methods ; Sensitivity and Specificity

OBJECTIVEWe have evaluated the direct effect of ampelopsis (APS) on duck hepatitis B virus (DHBV) replication in ducklings in vivo.

METHODOne-day-old ducklings were infected with DHBV. After infection for 7 days, the animals were treated with APS at dosages of 70, 150, 300 mg x kg(-1) of body weight via the oral route. The drug was given twice per day for 10 days continuously, and normal saline was used as control. The blood was drawn from the posterior tibial vein of all ducks before treatment (T0), after the medication for 5 (T5), 10 (T10) days and withdrawal of the drug for 3 days (P3). DHBV DNA in duck serum was detected by dot blot.

RESULTThe duck serum DHBV-DNA levels were reduced in the group of APS (150, 300 mg x kg(-1)) after treated for 5 and 10 days and the levels of DHBV-DNA did not markedly relapse in both groups of APS after withdrawal of the drug for 3 days. We provide the first evidence that APS can efficiently inhibits DHBV replication in ducks in vivo.

CONCLUSIONAPS therefore warrants further investigation as a potential therapeutic agent for HBV infections.

Ampelopsis ; chemistry ; Animals ; Antiviral Agents ; pharmacology ; DNA, Viral ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Ducks ; blood ; virology ; Hepatitis B Virus, Duck ; drug effects ; metabolism ; physiology ; Virus Replication ; drug effects

OBJECTIVETo discuss the possibility of hepatitis B virus (HBV) transmission through dental handpieces.

METHODSInvestigation was carried on methods for disinfecting and sterilizing dental handpieces and the condition of HBsAg contamination on dental handpieces before and after disinfection and sterilization by randomly sampling all special stomatological hospitals and dental clinics in a same city and 10 dental departments from the third, second and first class hospitals. The possibility of HBV transmission through dental handpieces was probed by investigating whether ducks can be infected by bath liquid of dental handpieces contaminated by DHBV, while in such bath liquid, DHBV can not be detected by serum dot hybridization.

RESULTSFrom 2001 to 2004, in methods to disposing dental handpieces, the use of autoclave was remarkably increased while of the disinfectant wipe, immersion and other methods was remarkably decreased. The positive rate of HBsAg from dental handpieces in practice was 1.65%. It was evident that the bath liquid of dental handpieces contaminated by DHBV can conduct infection in vivo test of duck, while DHBV can not be detected in such bath liquid by serum dot hybridization, it is proved that the negative result of HBsAg in non-sterilized dental handpieces can not eliminate the possibility of HBV transmission through dental handpieces.

CONCLUSIONThere might exist the possibility of HBV transmission through dental handpieces however, the autoclaves might kill the virus contaminating on dental handpieces.

Animals ; DNA, Viral ; blood ; Dental Instruments ; virology ; Ducks ; virology ; Equipment Contamination ; Hepatitis B ; transmission ; Hepatitis B Virus, Duck ; genetics ; isolation & purification ; Sterilization ; methods ; standards

OBJECTIVETo study the inhibitory effect of binding peptides on duck hepatitis B virus (DHBV) replication in duck hepatocytes.

METHODSSpecific binding peptides to duck hepatitis B virus polymerase (DHBVP) were screened by phage display technology (PDT), then were sequenced and synthesized. Binding peptides were added into primary culture of duck hepatocytes infected with DHBV in vitro. DHBV-DNA in the cytoplasm, cell nucleus and medium supernatant was assayed over time.

RESULTSSeven binding peptides were obtained after 3-round screening by PDT. Duck primary hepatocytes infected by DHBV were treated with above obtained binding peptides. The DHBV-DNA levels in medium supernatant and cytoplasm of duck hepatocytes treated with synthesized peptides (the 3rd and the 6th peptide) were significantly lower than those of control cells (P<0.05).

CONCLUSIONSpecific binding peptides to DHBVP could inhibit the replication of DHBV.

Animals ; Cells, Cultured ; Ducks ; Hepadnaviridae Infections ; virology ; Hepatitis B Virus, Duck ; drug effects ; genetics ; Hepatitis, Viral, Animal ; virology ; Hepatocytes ; virology ; Peptide Nucleic Acids ; pharmacology ; RNA-Directed DNA Polymerase ; metabolism ; Virus Replication ; drug effects

Brown ducks carrying DHBV were widely used as hepatitis B animal model in the research of the activity and toxicity of anti-HBV dugs. Studies showed that the ratio of DHBV carriers in the brown ducks in Guilin region was relatively high. Nevertheless, the characters of the DHBV genome of Guilin brown duck remain unknown. Here we report the cloning of the genome of Guilin brown duck DHBV and the sequence analysis of the genome. The full length of the DHBV genome of Guilin brown duck was 3 027bp. Analysis using ORF finder found that there was an ORF for an unknown peptide other than S-ORF, PORF and C-ORF in the genome of the DHBV. Vector NTI 8. 0 analysis revealed that the unknown peptide contained a motif which binded to HLA * 0201. Aligning with the DHBV sequences from different countries and regions indicated that there were no obvious differences of regional distribution among the sequences. A fluorescence quantitative PCR for detecting DHBV was establishment based on the recombinant plasmid pGEM-DHBV-S constructed. This study laid the groundwork for using Guilin brown duck as a hepatitis B animal model.
Animals ; Base Sequence ; China ; epidemiology ; Cloning, Molecular ; Ducks ; Genome, Viral ; Hepadnaviridae Infections ; diagnosis ; veterinary ; virology ; Hepatitis B Virus, Duck ; classification ; genetics ; isolation & purification ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; methods ; Poultry Diseases ; diagnosis ; virology

Animals ; Antiviral Agents ; pharmacology ; therapeutic use ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Ducks ; Glycyrrhizic Acid ; pharmacology ; therapeutic use ; Hepadnaviridae Infections ; drug therapy ; Hepatitis B Virus, Duck ; drug effects ; Hepatitis, Viral, Animal ; drug therapy ; Phytotherapy