| activation and antiviral effect of acyclovir in cells infected with a varicella-like simian virus. | acyclovir inhibited the replication of a varicella-like simian virus (dhv-1) in cell culture (vero cells) with an ed50 of 38 +/- 2 microm. the activation of acyclovir in this cell culture system was compared with that in the cell system with human varicella zoster virus (vzv). extracts of cells infected with dhv-1 catalyzed the phosphorylation of acyclovir. the phosphorylation was inhibited by dthd, suggesting the catalyst was a dthd kinase. electrophoresis of cytosol fractions on polyacrylamide ... | 1982 | 6285734 |
| molecular analysis of duck hepatitis virus type 1 reveals a novel lineage close to the genus parechovirus in the family picornaviridae. | duck hepatitis virus type 1 (dhv-1) was previously classified as an enterovirus, based primarily on observed morphology and physicochemical properties of the virion. the complete nucleotide sequences of two strains (drl-62 and r85952) of dhv-1 have been determined. excluding the poly(a) tail, the genomes are 7691 and 7690 nt, respectively, and contain a single, large open reading frame encoding a polyprotein of 2249 aa. the genome of dhv-1 is organized as are those of members of the family picor ... | 2006 | 17030865 |
| molecular analysis of duck hepatitis virus type 1 indicates that it should be assigned to a new genus. | the genome sequences of three duck hepatitis virus type 1 (dhv-1) strains were determined. comparative sequence analyses showed that they possessed a typical picornavirus genome organization apart from the unique possession of three in-tandem 2a genes. the 2a1 protein of dhv-1 is an aphthovirus-like 2a protein; the 2a2 protein is not related to any known picornavirus protein; the 2a3 protein is a human parechovirus-like 2a protein. several other features were found to be unique to the dhv-1 geno ... | 2007 | 17067712 |
| molecular characterization of a new serotype of duck hepatitis virus. | duck hepatitis strains 90d and 04g were determined to be antigenically unrelated to type 1 duck hepatitis virus (dhv-1) by in vitro cross-neutralization assay. the genome sequences of 90d and 04g revealed that both strains of the new serotype dhv (n-dhv) possessed a typical picornavirus genome organization apart from the unique possession of three in-tandem 2a genes present in dhv-1. the 2a1, 2a2, and 2a3 proteins represented an aphthovirus-like 2a protein, aig1-like protein, and human parechovi ... | 2007 | 17292992 |
| molecular analysis of duck hepatitis virus type 1. | the genome sequence of a duck hepatitis virus type 1 (dhv-1) strain was determined. comparative sequence analysis showed that the genome possesses a typical picornarivus organization and also exhibits several unique features, such as the similarity of internal ribosome entry site to that of porcine teschovirus 1 and hepatitis c virus, the presence of a longest 3' untranslated region and a shorter leader protein in the picornaviridae, the absence of a predicted maturation cleavage of vp0, the ass ... | 2007 | 17300822 |
| a distinct group of hepacivirus/pestivirus-like internal ribosomal entry sites in members of diverse picornavirus genera: evidence for modular exchange of functional noncoding rna elements by recombination. | the 5' untranslated regions (utrs) of the rna genomes of flaviviridae of the hepacivirus and pestivirus genera contain internal ribosomal entry sites (iress) that are unrelated to the two principal classes of iress of picornaviridae. the mechanism of translation initiation on hepacivirus/pestivirus (hp) iress, which involves factor-independent binding to ribosomal 40s subunits, also differs fundamentally from initiation on these picornavirus iress. ribosomal binding to hp iress requires conserve ... | 2007 | 17392358 |
| development of one-step reverse transcriptase-polymerase chain reaction to detect duck hepatitis virus type 1. | a one-step reverse transcriptase-polymerase chain reaction (rt-pcr) method was developed and optimized for the detection of duck hepatitis virus type 1 (dhv-1) using the viral gene-spin viral dna/rna extraction kit. a pair of dhv-1-specific primers was designed against the gene encoding rna-dependent rna polymerase (3d gene). using rna prepared from duckling liver samples infected with two reference and seven korean field isolates of dhv-1, one-step rt-pcr with dhv1-specific primers amplified a ... | 2007 | 17626480 |
| sequence analysis of a duck picornavirus isolate indicates that it together with porcine enterovirus type 8 and simian picornavirus type 2 should be assigned to a new picornavirus genus. | in a 1990 outbreak, a virus isolated in taiwan from the intestines of ducks showing signs of hepatitis was tentatively classified as a picornavirus on the basis of physical, chemical, and morphological characteristics. the virus was cloned and then found not to be type 1 duck hepatitis virus (dhv-1) or a new serotype of duck hepatitis virus (n-dhv) by serum neutralization. complete genome sequencing indicated that the virus genome had 8351 nucleotides and the typical picornavirus genome organiza ... | 2007 | 17686542 |
| recent korean isolates of duck hepatitis virus reveal the presence of a new geno- and serotype when compared to duck hepatitis virus type 1 type strains. | duck hepatitis was first reported in 1985 in korea. the complete nucleotide sequence of two past korean isolates, dhv-hs and dhv-hss, isolated in 1994 and 1995, and four recent korean isolates, ap-03337, ap-04009, ap-04114 and ap-04203 isolated in 2003 and 2004, were determined. phylogenetic analysis using the 3d protein sequence confirmed that the previously characterized duck hepatitis virus type 1 strains and the six korean isolates described here constitute a monophyletic group and form two ... | 2007 | 17701025 |
| differential diagnosis between type-specific duck hepatitis virus type 1 (dhv-1) and recent korean dhv-1-like isolates using a multiplex polymerase chain reaction. | duck hepatitis can be caused by four types of viruses: duck hepatitis virus (dhv) type 1 (dhv-1), dhv-1a (a variant strain of dhv-1), dhv-2 and dhv-3. in korea, duck hepatitis has been associated with two types of dhv-1, original dhv-1 type-specific strain (dhv-1s) and the recently reported dhv-1 variant strains (dhv-1v). the pathogenicity and pathological findings of ducklings infected with the recent dhv-1v isolates, ap-04114 and ap-04203, were almost identical to those infected with members o ... | 2008 | 18393095 |
| classification of duck hepatitis virus into three genotypes based on molecular evolutionary analysis. | the nucleotide sequences of the complete vp1, vp0, vp3, and partial 3d regions of seven duck hepatitis virus (dhv) serotype 1 (dhv-1) strains isolated in china between 2001 and 2007 and one dhv-1 strain originally obtained from atcc were determined and compared with previously available dhv sequences in genbank. phylogenetic analysis on the basis of vp1 sequences demonstrated three distinct genetic groups. there was an excellent concordance among the genetic groups assigned based on the complete ... | 2008 | 18437547 |
| molecular detection and typing of duck hepatitis a virus directly from clinical specimens. | to develop a new approach for the detection and typing of duck hepatitis a virus (dhav), a pair of non-degenerate primers was designed to amplify a approximately 250-bp genomic region in the 5'utr. 3 reference strains and 6 duck embryo-derived isolates from various regions in china, involving 2 serotypes, were successfully amplified with the primer set. by determining the nucleotide sequence of the amplicon, a molecular typing method was developed. if isolate sequences were compared to dhav 5'ut ... | 2008 | 18462894 |
| identification and molecular analysis of the highly pathogenic duck hepatitis virus type 1 in hubei province of china. | duck hepatitis virus types 1 (dhv-1) jx strain was isolated from infected ducklings with clinical symptoms from hubei province of china. these isolated strains showed high pathogenicity to both duck embryo and duckling in duck embryo neutralization assay and animal infection experiment. the complete genome of jx strain was sequenced. comparative genome analysis with other available strains in genbank indicated that jx strain shared 94-99% similarity at the nucleotide level and 95-99% at amino ac ... | 2008 | 18486957 |
| development and application of a one-step real-time taqman rt-pcr assay for detection of duck hepatitis virus type1. | a one-step real-time rt-pcr assay (rrt-pcr) was developed for efficient detection of duck hepatitis virus type1 (dhv-1). a pair of specific primers was designed against the conserved region in the 3d gene that encodes the rna dependent rna polymerase with a single conserved taqman probe. the detection limit of this assay was 10 viral genomic copies per reaction and it was highly specific to dhv-1. the rrt-pcr assay was used to determine the distribution and concentration of dhv-1 virulent strain ... | 2008 | 18611411 |
| development and application of a reverse transcriptase polymerase chain reaction to detect chinese isolates of duck hepatitis virus type 1. | we developed a reverse transcriptase polymerase chain reaction (rt-pcr) method for the detection of duck hepatitis virus type 1 (dhv-1) in the tissues of infected and clinically affected ducks and in chick and duck embryos. we found the assay to be effective in detecting the virus in china, where it is being used in studies on the epidemiology of the disease. we applied this simple and rapid diagnostic method to the detection of dhv isolates grown in chick and duck embryos and in tissues obtaine ... | 2009 | 18706944 |
| development and application of a reverse transcriptase polymerase chain reaction to detect chinese isolates of duck hepatitis virus type 1. | we developed a reverse transcriptase polymerase chain reaction (rt-pcr) method for the detection of duck hepatitis virus type 1 (dhv-1) in the tissues of infected and clinically affected ducks and in chick and duck embryos. we found the assay to be effective in detecting the virus in china, where it is being used in studies on the epidemiology of the disease. we applied this simple and rapid diagnostic method to the detection of dhv isolates grown in chick and duck embryos and in tissues obtaine ... | 2009 | 19475729 |
| [genomic sequence of a new serotype duck hepatitis virus]. | a strain of highly pathogenic duck hepatitis virus was isolated in south china from a pekin duck flock in 1999. no cross reaction with type 1 and 3 duck hepatitis virus was found by serum neutralization. we suggested the strain should be classified as a new serotype of duck hepatitis virus and named it as dhv-n g strain in our previous study. we wanted to reveal the evolution of this virus in molecular level and gene sequence differences between it and dhv-1 strains. | 2009 | 19623953 |
| development of duck hepatitis a virus type 3 vaccine and its use to protect ducklings against infections. | a variant type of duck hepatitis a virus (dhav), dhav-3 was recently discovered in south korea and china. sequence analyses verified that the variant is genetically or serologically different from the dhav-1 and dhav-2 types. duck hepatitis had been reported in south korea since 1985 and an attenuated dhav-1 vaccine had efficiently prevented epidemics of dhav-1 until 2002. despite the dhav-1 based vaccine in use the novel dhav-3 circulating in south korea remains to be a threat to duckling farmi ... | 2009 | 19747575 |
| generation of infectious and pathogenic duck hepatitis virus type 1 from cloned full-length cdna. | a full-length cdna clone of duck hepatitis virus type 1 (dhv-1) isolated from duck was assembled in the plasmid vector pbluescript ii sk+. rna synthesized in vitro by means of a sp6 promoter inserted in front of the cdna produced infectious particles after transfection of bhk-21 cells, as shown by the appearance of cytopathic effect. the rescued virus was also found to be highly pathogenic to young ducks by intradermal injection and resulted in a fatal disease indistinguishable from that of wild ... | 2010 | 19919844 |
| [construction of infectious molecular clone of duck hepatitis virus type 1 cl strain]. | to construct an infectious clone for studying functions of duck hepatitis virus (dhv) typel genome by reverse genetic technique. | 2009 | 20222452 |
| development and evaluation of a vp1-elisa for detection of antibodies to duck hepatitis type 1 virus. | the vp1-encoding gene of the duck hepatitis type 1 virus (dhv-1) hp-1 strain was cloned and expressed in escherichiacoli. the open reading frame (orf) of vp1 comprised 714 bp and encoded 238 amino acids, with a predicated molecular mass of 26.5 kda. the expressed vp1 fusion protein in e. coli was detected by western blotting with duck anti-dhv-1 polyclonal serum. a vp1-elisa using the expressed vp1 protein as a coating antigen for the detection of antibodies to dhv-1 in ducks was developed. in c ... | 2010 | 20609374 |
| expression of the c-terminal orf2 protein of duck astrovirus for application in a serological test. | duck astrovirus (dastv) is an important pathogen causing duck viral hepatitis (dvh), a highly contagious and fatal disease in young ducklings. to provide an antigen for a diagnostic serum test, the c-terminus of dastv orf2 protein was expressed in escherichia coli. four positive and 30 negative sera were used to validate the purified orf2 protein by developing an indirect enzyme-linked immunosorbent assay (elisa). no cross-reactions were found against other duck pathogens, including duck hepatit ... | 2010 | 20863856 |
| the duck hepatitis virus 5'-utr possesses hcv-like ires activity that is independent of eif4f complex and modulated by downstream coding sequences. | duck hepatitis virus (dhv-1) is a worldwide distributed picornavirus that causes acute and fatal disease in young ducklings. recently, the complete genome of dhv-1 has been determined and comparative sequence analysis has shown that possesses the typical picornavirus organization but exhibits several unique features. for the first time, we provide evidence that the 626-nucleotide-long 5'-utr of the dhv-1 genome contains an internal ribosome entry site (ires) element that functions efficiently bo ... | 2011 | 21450110 |
| detection and characterization of avian nephritis virus in ducklings. | the first evidence of avian nephritis virus (anv) in ducks is described. a diagnostic investigation was performed on three duck farms in croatia. samples from dead-in-shell ducklings and ducklings aged 30 days were collected and prepared for molecular and histopathological examination. intestinal and liver samples were tested by polymerase chain reaction (pcr) for the presence of anv, duck enteritis virus, duck hepatitis virus 1 and derzsy's disease virus. multiple tissues were collected for his ... | 2011 | 21500037 |
| goose haemorrhagic hepatitis caused by a new subtype duck hepatitis type 1 virus. | duck hepatitis type 1 virus (dhv-1) causes a fatal disease in ducklings but there is no report of dhv-1 isolation from goose. recently, cases of a new disease in overfeeding geese were reported from china. the cases were characterized by haemorrhagic hepatitis lesions on liver after post mortem examinations. the flocks showed about 20-40% morbidity and less than 5% mortality. the histopathological lesions showed destroyed structure of hepatocytic tissue, severe vacuolation and necrosis of hepato ... | 2011 | 21641125 |
| recovery of duck hepatitis a virus 3 from a stable full-length infectious cdna clone. | recently, duck hepatitis a virus 3 (dhav-3) with genetically distinct characteristics from dhav-1 and dhav-2 was recognized in south korea and china. in this short communication, we successfully constructed a stable full-length infectious cdna clone derived from dhav-3 by solving instability of cloned full-length cdna in escherichia coli (e. coli). the cdna fragments amplified from the genome of dhav-3 were assembled and inserted into a low-copy-number plasmid. finally, a full-length cdna clone ... | 2011 | 21801768 |
| analysis of codon usage in type 1 and the new genotypes of duck hepatitis virus. | in this study, an abundant (a+u)% and low codon bias were revealed in duck hepatitis virus type 1 (dhv-1) and the new serotype strains isolated from taiwan, south korea and mainland china (dhv-n). the general correlation between base composition and codon usage bias suggests that mutational pressure rather than natural selection is the main factor that determines the codon usage bias in these samples. by comparative analysis of the codon usage patterns of 40 orfs of dhv, we found that all of dhv ... | 2011 | 21708221 |
| the development of a rapid sybr green i-based quantitative pcr for detection of duck circovirus. | this report describes a one-step real-time polymerase chain reaction assay based on sybr green i for detection of a broad range of duck circovirus (ducv). align with all ducv complete genome sequences and other genus circovirus download from the genbank (such as goose circovirus, pigeon circovirus), the primers targets to the replicate gene of ducv were designed. the detection assay was linear in the range of 1.31 × 102-1.31 × 107 copies/μl. the reaction efficiency of the assay using the slope ( ... | 2011 | 21978576 |
| Duck Hepatitis A Virus Possesses a Distinct Type IV Internal Ribosome Entry Site Element of Picornavirus. | Sequence analysis of duck hepatitis virus type 1 (DHV-1) led to its classification as the only member of a new genus, Avihepatovirus, of the family Picornaviridae, and so was renamed duck hepatitis A virus (DHAV). The 5' untranslated region (5' UTR) plays an important role in translation initiation and RNA synthesis of the picornavirus. Here, we provide evidence that the 651-nucleotide (nt)-long 5' UTR of DHAV genome contains an internal ribosome entry site (IRES) element that functions efficien ... | 2012 | 22090106 |
| isolation and characterization of a low pathogenic duck hepatitis a virus 3 from south korea. | the d11-jw-018 strain of duck hepatitis a virus (dhav) was isolated from 7-day-old ducklings in kyeonggi province, south korea with no clinical signs of typical hepatitis. phylogenetic analyzed of whole genome showed that d11-jw-018 strain was belonged to dhav-3 genotype. the pathogenicity of the d11-jw-018 strain in 1-, 7-, 14-, and 21-day-old ducklings was examined. mortality of d11-jw-018 strain was lower than drl-62 (dhav-1) age-dependent but incubation period was longer in 1-day-old ducklin ... | 2012 | 23265242 |
| genetic characterization of a novel picornavirus in turkeys (meleagris gallopavo) distinct from turkey galliviruses and megriviruses and distantly related to the members of the genus avihepatovirus. | this study reports the metagenomic detection and complete genome characterization of a novel turkey picornavirus from faecal samples of healthy (1/3) and affected (6/8) commercial turkeys with enteric and/or stunting syndrome in hungary. the virus was detected at seven of the eight farms examined. the turkey/m176-tuasv/2011/hun genome (kc465954) was genetically different from the currently known picornaviruses of turkey origin (megriviruses and galliviruses), and showed distant phylogenetic rela ... | 2013 | 23559479 |
| live attenuated vaccine based on duck enteritis virus against duck hepatitis a virus types 1 and 3. | as causative agents of duck viral hepatitis, duck hepatitis a virus type 1 (dhav-1) and type 3 (dhav-3) causes significant economic losses in the duck industry. however, a licensed commercial vaccine that simultaneously controls both pathogens is currently unavailable. here, we generated duck enteritis virus recombinants (rc-kce-2vp1) containing both vp1 from dhav-1 (vp1/dhav-1) and vp1 from dhav-3 (vp1/dhav-3) between ul27 and ul26. a self-cleaving 2a-element of fmdv was inserted between the tw ... | 2016 | 27777571 |
| development and evaluation of a das-elisa for rapid detection of tembusu virus using monoclonal antibodies against the envelope protein. | since april 2010, tembusu virus (tmuv) which is a contagious pathogen of waterfowls, causing symptoms of high fever, loss of appetite and fall in egg production, has been reported in east of china. a double antibody sandwich enzyme-linked immunosorbent assay (das-elisa) which detects for tmuv was developed, using two monoclonal antibodies (mabs) against the tmuv envelope (e) protein. balb/c mice were immunized with purified recombinant e protein expressed in e. coli. three hybridoma cell lines d ... | 2014 | 24797141 |
| identification and expression analysis of the interferon-induced protein with tetratricopeptide repeats 5 (ifit5) gene in duck (anas platyrhynchos domesticus). | the interferon-induced proteins with tetratricopeptide repeats (ifits) protein family mediates antiviral effects by inhibiting translation initiation, cell proliferation, and migration in the interferon (ifn) dependent innate immune system. several members of this family, including ifit1, ifit2, ifit3 and ifit5, have been heavily studied in mammals. avian species contain only one family member, ifit5, and little is known about the role of this protein in birds. in this study, duck ifit5 (duifit5 ... | 2015 | 25816333 |
| anti-dhav-1 reproduction and immuno-regulatory effects of a flavonoid prescription on duck virus hepatitis. | the flavonoid prescription baicalin-linarin-icariin-notoginsenoside r1 (blin) has a curative effect on duck virus hepatitis (dvh) caused by duck hepatitis a virus type 1 (dhav-1). however, the mechanism of this curative effect is not understood. | 2017 | 28385083 |
| viral-host interaction in kidney reveals strategies to escape host immunity and persistently shed virus to the urine. | hepatitis a virus is one of five types of hepatotropic viruses that cause human liver disease. a similar liver disease is also identified in ducks caused by duck hepatitis a virus (dhav). notably, many types of hepatotropic viruses can be detected in urine. however, how those viruses enter into the urine is largely unexplored. to elucidate the potential mechanism, we used the avian hepatotropic virus to investigate replication strategies and immune responses in kidney until 280 days after infect ... | 2017 | 28038465 |
| treatment effect of a flavonoid prescription on duck virus hepatitis by its hepatoprotective and antioxidative ability. | duck virus hepatitis (dvh) caused by duck hepatitis a virus type 1 (dhav-1) is an acute and lethal disease of young ducklings. however, there is still no effective drug to treat dvh. | 2017 | 27927057 |
| the 2a2 protein of duck hepatitis a virus type 1 induces apoptosis in primary cell culture. | duck hepatitis a virus type 1, (dhav-1) 2a2(pro), is one of the most highly conserved viral proteins within the dhav serotypes. however, its effect on host cells is unclear. we predicted that dhav-1 2a2(pro) was a gtpase-like protein based on the results of multiple sequence alignment and homologous modeling analysis. upon transfection of a recombinant plasmid expressing dhav-1 2a2, cells displayed fragmented nuclei, chromatin condensation, oligonucleosome-sized dna ladder, and positive terminal ... | 2016 | 27314270 |
| phosphorylated codonopsis pilosula polysaccharide could inhibit the virulence of duck hepatitis a virus compared with codonopsis pilosula polysaccharide. | to screen effective anti-duck hepatitis a virus (dhav) drugs, we applied stmp-stpp method to prepare phosphorylated codonopsis pilosula polysaccharide (pcpps), the phosphorylation-modified product of codonopsis pilosula polysaccharide (cpps). the ir spectrum and field emission scanning electron microscope (fe-sem) were subsequently used to analyze the structure of pcpps. several tests were conducted to compare the anti-dhav activities of cpps and pcpps. the mtt method was used to compare the eff ... | 2017 | 27713010 |
| comparison of the anti-duck hepatitis a virus activities of phosphorylated and sulfated astragalus polysaccharides. | duck hepatitis a virus (dhav) (picornaviridae) causes an infectious disease in ducks which results in severe losses in duck industry. however, the proper antiviral supportive drugs for this disease have not been discovered. polysaccharide is the main ingredient of astragalus that has been demonstrated to directly and indirectly inhibit rna of viruses replication. in this study, the antiviral activities of astragalus polysaccharide (aps) and its derivatives against dhav were evaluated and compare ... | 2017 | 27703041 |
| molecular genotyping of duck hepatitis a viruses (dhav) in vietnam. | the aim of this study was to identify the genetic characteristics and molecular genotyping of duck hepatitis a virus (dhav) isolated in vietnam during 2009-2013. | 2016 | 27694732 |
| hepatitis virus infections in poultry. | viral hepatitis in poultry is a complex disease syndrome caused by several viruses belonging to different families including avian hepatitis e virus (hev), duck hepatitis b virus (dhbv), duck hepatitis a virus (dhav-1, -2, -3), duck hepatitis virus types 2 and 3, fowl adenoviruses (fadv), and turkey hepatitis virus (thv). while these hepatitis viruses share the same target organ, the liver, they each possess unique clinical and biological features. in this article, we aim to review the common an ... | 2016 | 27610716 |
| development and evaluation of indirect elisas for the detection of igg, igm and iga1 against duck hepatitis a virus 1. | duck hepatitis a virus 1 (dhav-1) is the principal pathogen that causes duck viral hepatitis (dhv), a highly fatal infectious disease in ducklings. given the importance of the humoral immune response in the clearance of dhav-1, indirect enzyme-linked immunosorbent assays (i-elisas) to detect immune indices, including igg, igm and iga1, were developed and evaluated in this study. the optimal concentrations of coating-antigen were 1.79μg/ml, 2.23μg/ml and 2.23μg/ml for igg, igm and iga1, respectiv ... | 2016 | 27577105 |
| a one-step duplex rrt-pcr assay for the simultaneous detection of duck hepatitis a virus genotypes 1 and 3. | duck hepatitis a virus (dhav) is a highly infectious pathogen that causes significant bleeding lesions in the viscera of ducklings less than 3 weeks old. there are three serotypes of dhav: serotype 1 (dhav-1), serotype 2 (dhav-2) and serotype 3 (dhav-3). these serotypes have no cross-antigenicity with each other. to establish an rrt-pcr assay for the rapid detection of a mixed infection of dhav-1 and dhav-3, two pairs of primers and a pair of matching taqman probes were designed based on conserv ... | 2016 | 27435338 |
| [development and evaluation of an inactivated bivalent vaccine against duck viral hepatitis]. | the rapid mutation and widely spread of duck hepatitis a virus (dhav) lead to the vast economic loss of the duck industry. to prepare and evaluate bivalent inactivated vaccine laboratory products of dhav, 6 strains were screened from 201 dhav-1 strains and 38 dhav-3 strains by using serotype epidemiological analysis in most of the duck factory. vaccine candidate strains were selected by eld50 and ld50 tests in the 6 strains. continuously passaged, the 5th passaged duck embryos bodies grinding fl ... | 2015 | 26939441 |
| replication cycle of duck hepatitis a virus type 1 in duck embryonic hepatocytes. | duck hepatitis a virus type 1 (dhav-1) is an important agent of duck viral hepatitis. until recently, the replication cycle of dhav-1 is still unknown. here duck embryonic hepatocytes infected with dhav-1 were collected at different time points, and dynamic changes of the relative dhav-1 gene expression during replication were detected by real-time pcr. and the morphology of hepatocytes infected with dhav was evaluated by electron microscope. the result suggested that the adsorption of dhav-1 sa ... | 2016 | 26874587 |
| circulation and in vivo distribution of duck hepatitis a virus types 1 and 3 in infected ducklings. | the circulation of duck hepatitis a virus types 1 (dhav-1) and 3 (dhav-3) in southeast asia has resulted in a continuously changing epidemiological scenario. in this study, a duplex real-time pcr assay for simultaneous quantitative detection of dhav-1 and dhav-3 was established, and 200 liver samples from dead ducklings collected from 31 different flocks in shandong province, china, were tested. fifty-eight (29.0 %) samples from 13 flocks were positive for dhav-1 single infection, 113 (56.5 %) s ... | 2016 | 26597185 |
| duck hepatitis a virus serotype 1 minigenome: a model for studying the viral 3'utr effect on viral translation. | to date, the genetic replication and translation mechanisms as well as the pathogenesis of duck hepatitis a virus type 1 (dhav-1) have not been adequately characterized due to the lack of a reliable and efficient cell culture system. although the full-length infections clone system is the best platform to manipulate the virus, it is relatively difficult to assemble this system due to the lack of a suitable cell line. it has been proven that the minigenome system an efficient reverse genetics sys ... | 2015 | 26578153 |
| identification of a conserved neutralizing linear b-cell epitope in the vp1 proteins of duck hepatitis a virus type 1 and 3. | duck virus hepatitis (dvh), mainly caused by duck hepatitis a virus (dhav), is a severe disease threaten to duck industry and has worldwide distribution. as the major structural protein, the vp1 protein of dhav is able to induce neutralizing antibody in ducks. in this study, a monoclonal antibody (mab) 4f8 against the intact dhav-1 particles was used to identify the possible epitope in the three serotypes of dhav. the mab 4f8 had weak neutralizing activities to both dhav-1 and dhav-3, and reacte ... | 2015 | 26427545 |
| development of an indirect elisa method based on the vp3 protein of duck hepatitis a virus type 1 (dhav-1) for dual detection of dhav-1 and dhav-3 antibodies. | an indirect enzyme-linked immunosorbent assay (i-elisa) based on the recombinant vp3 protein of duck hepatitis a virus type 1 (dhav-1) was developed and evaluated in this study. the optimal antigen, serum and enzyme-labeled antibody dilutions were 1:160 (0.94μg), 1:160 and 1:2000, respectively. the optimal blocking buffer was 1% gelatin. the cutoff value was determined to be 0.332, and the analytical sensitivity was 1:1280 (od450-630=0.37). the results of the specificity evaluation showed that n ... | 2015 | 26341062 |
| molecular evolution and genetic analysis of the major capsid protein vp1 of duck hepatitis a viruses: implications for antigenic stability. | the duck hepatitis a virus (dhav), a member of the family picornaviridae, is the major cause of outbreaks with high mortality rates in young ducklings. it has three distinctive serotypes and among them, serotypes 1 (dhav-1) and 3 (dhav-3) were recognized in china. to investigate evolutionary and antigenic properties of the major capsid protein vp1 of these two serotypes, a primary target of neutralizing antibodies, we determined the vp1 coding sequences of 19 dhav-1 (spanning 2000-2012) and 11 d ... | 2015 | 26173145 |
| effects of bush sophora root polysaccharide and its sulfate on immuno-enhancing of the therapeutic dvh. | bush sophora root polysaccharide (bsrps) and its sulfate, sulfated bush sophora root polysaccharide (sbsrps), possess the antiviral activities against duck hepatitis a virus. however their antiviral mechanisms are still not clear. this paper reported their immuno-enhancing roles in the therapeutic effects for duck virus hepatitis (dvh). the effects of bsrps and sbsrps on stimulating lymphocyte proliferation were investigated by mtt methods. after that, ducklings were challenged with dhav and tre ... | 2015 | 26118485 |
| epidemiology and molecular characterisation of duck hepatitis a virus from different duck breeds in egypt. | duck hepatitis virus (dhv) is an acute highly contagious disease of ducklings caused by three distinct serotypes of duck hepatitis a virus (dhav), a member of the rna family picornaviridae, where serotype 1 is the most widespread serotype worldwide. to date, little if any is known about the prevalence and genetic characterisation of dhav outside asia. the current study describes surveillance on dhv in 46 commercial duck farms in egypt with a history of high mortality in young ducklings from 3 to ... | 2015 | 25862279 |
| identification of a conserved b-cell epitope on duck hepatitis a type 1 virus vp1 protein. | the vp1 protein of duck hepatitis a virus (dhav) is a major structural protein that induces neutralizing antibodies in ducks; however, b-cell epitopes on the vp1 protein of duck hepatitis a genotype 1 virus (dhav-1) have not been characterized. | 2015 | 25706372 |
| analysis of synonymous codon usage patterns in duck hepatitis a virus: a comparison on the roles of mutual pressure and natural selection. | codon usage patterns of duck hepatitis a virus (hav) were studied in the present study. the major trends of codon usage patterns were analyzed using principal component analysis on the basis of the relative synonymous codon usage values. correlation analysis was utilized to reveal the associations of the first two major axes of pca and nucleotide- or amino acid-relevant indices. our results showed that compositional constraint and/or mutational pressure are major factors influencing codon usage ... | 2014 | 25674595 |
| [molecular characteristic of duck hepatitis a virus type 1 causing pancreatitis ]. | [objective] we studied the molecular characteristics of the full-length genome of duck hepatitis a virus type 1 causing pancreatitis in muscovy ducklings. [methods] we determined the entire genomic sequence of duck hepatitis a virus type 1 strain mpzj1206 using reverse transcription polymerase chain reaction assay and analyzed the bioinformatics of the viral genome sequence. [ results] the genome length of strain mpzj1206 comprised 7703 bases, with a g + c content of 43.05%. the genome of mpzj12 ... | 2014 | 25522597 |
| recombinant vp1 protein of duck hepatitis virus 1 expressed in pichia pastoris and its immunogenicity in ducks. | the vp1 gene of duck hepatitis virus type 1 (dhv-1) strain vj09 was amplified by reverse transcription pcr from the liver of a duckling with clinical symptoms of viral hepatitis. the resulting vp1 cdna was 720 bp in length and encoded a 240-amino-acid protein. in vp1 gene-based phylogenetic analysis, the vj09 strain grouped with dhv-1 genotype c. the vp1 gene was inserted into the expression vector ppiczαa and expressed in pichia pastoris. the expressed vp1 protein was purified and identified by ... | 2014 | 25518714 |
| the anti-dhav activities of astragalus polysaccharide and its sulfate compared with those of bsrps and its sulfate. | this paper studied the anti-duck hepatitis a virus (dhav) activities of astragalus polysaccharide (aps) and its sulfate (saps) compared with those of bush sophora root polysaccharide (bsrps) and its sulfate (sbsrps). the antiviral activities of aps and saps were measured by mtt and real-time pcr methods, in vitro. in vivo experiment, the mortality rate and the evaluation indexes of hepatic injury, peroxidative injury and immune level were measured. just like the condition of bsrps and sbsrps, th ... | 2015 | 25498644 |
| the prevalence of duck hepatitis a virus types 1 and 3 on korean duck farms. | this study reports the prevalence of duck hepatitis a virus (dhav) types 1 and 3 on korean duck farms. by rt-nested pcr assays specific for dhav-1 or dhav-3, dhav-1 was detected in 9 of 157 liver samples (5.7 %) from 2 of 30 farms (6.7 %), and dhav-3 was positive in 104 of 157 liver samples (66.2 %) from 23 of 30 farms (76.7 %). dual infections with dhav-1 and dhav-3 were detected in 23 of 157 samples (14.6 %) from 5 of 30 farms (16.7 %). the data indicate that dhav-3 infections are prevalent an ... | 2015 | 25359107 |
| the cd8α gene in duck (anatidae): cloning, characterization, and expression during viral infection. | cluster of differentiation 8 alpha (cd8α) is critical for cell-mediated immune defense and t-cell development. although cd8α sequences have been reported for several species, very little is known about cd8α in ducks. to elucidate the mechanisms involved in the innate and adaptive immune responses of ducks, we cloned cd8α coding sequences from domestic, muscovy, mallard, and spotbill ducks using reverse transcription polymerase chain reaction (rt-pcr). each sequence consisted of 714 nucleotides a ... | 2015 | 25332128 |
| roles of the antioxidant properties of icariin and its phosphorylated derivative in the protection against duck virus hepatitis. | duck viral hepatitis (dvh) is an acute disease of young ducklings with few convenient and effective veterinary drugs to treat. in pathology, present study mainly focused on the immune mechanism, but very few studies have concerned with the role of oxidative stress in the pathogenesis of dvh. to study the antioxidative and hepatoprotective effects of icariin and its phosphorylated derivative against dvh, we prepared phosphorylated icariin (p-icariin) using the sodium trimetaphosphate-sodium tripo ... | 2014 | 25244948 |
| virulent and attenuated strains of duck hepatitis a virus elicit discordant innate immune responses in vivo. | previous studies of duck hepatitis a virus infection have focused only on the pathogenicity and host response of one strain. here, we show that the virulent sh strain and the attenuated fc64 strain induced varied pathogenicity, apoptosis and immune responses in the livers of 1-day-old ducklings. sh infection caused apoptosis and visible lesions in the liver; serum aspartate aminotransferase, alanine transaminase, alkaline phosphatase, γ-glutamyltransferase and total bilirubin activities were mar ... | 2014 | 25217614 |
| characterization of monoclonal antibodies against duck hepatitis type 1 virus vp1 protein. | the vp1 protein of duck hepatitis type 1 virus (dhv-1), one of the major structural proteins, is able to induce neutralizing antibody in ducks, but a monoclonal antibody (mab) against vp1 protein has never been characterized. four hybridoma cell lines secreting anti dhv-1a vp1 mabs were prepared and designated 2d9, 2d10, 5f7, and 3e8. immunoglobulin subclass tests differentiated them as igg1 (2d9 and 2d10) and igg2b (5f7 and 3e8). dot blot and western blotting assays showed that mabs reacted wit ... | 2014 | 25110119 |
| detection, differentiation, and vp1 sequencing of duck hepatitis a virus type 1 and type 3 by a 1-step duplex reverse-transcription pcr assay. | duck hepatitis a virus (dhav) is an infectious pathogen causing fatal duck viral hepatitis in ducklings. although both the inactivated vaccines and live attenuated vaccines have been used to protect ducklings, dhav-1 and dhav-3 still cause significant serious damage to the duck industry in china and south korea. for rapid detection, differentiation, and epidemic investigation of dhav in china, a genotype-specific 1-step duplex reverse-transcription (rt) pcr assay was established in this study. t ... | 2014 | 25012848 |
| propagation of viruses infecting waterfowl on continuous cell lines of muscovy duck (cairina moschata) origin. | duck circovirus, duck hepatitis a virus 1, goose parvovirus and goose haemorrhagic polyomavirus are economically damaging pathogens of waterfowl, and replicate poorly or not at all in established cell lines. age1.cr, age1.cr.pix and age1.cs cell lines, originating from the muscovy duck, were tested for their suitability to isolate and identify these viruses. immunofluorescence (if) and quantitative polymerase chain reaction investigations verified that all cell lines are permissive for all four ... | 2014 | 24992264 |
| molecular cloning and expression analysis of ferritin, heavy polypeptide 1 gene from duck (anas platyrhynchos). | h-ferritin is a core subunit of the iron storage protein ferritin, and is related to the pathogenesis of malignant diseases. a differential expressed sequence tag of the ferritin, heavy polypeptide 1 gene (fth1) was obtained from our previously constructed suppression subtractive cdna library from 3-day-old ducklings challenged with duck hepatitis virus type i (dhv-1). the expression and function of fth1 in immune defense against infection remains largely unknown in ducks. in this study, the ful ... | 2014 | 24981929 |
| chickens host diverse picornaviruses originated from potential interspecies transmission with recombination. | while chickens are an important reservoir for emerging pathogens such as avian influenza viruses, little is known about the diversity of picornaviruses in poultry. we discovered a previously unknown diversity of picornaviruses in chickens in hong kong. picornaviruses were detected in 87 cloacal and 7 tracheal samples from 93 of 900 chickens by reverse transcription-pcr, with their partial 3d(pol) gene sequences forming five distinct clades (i to v) among known picornaviruses. analysis of eight g ... | 2014 | 24906980 |
| simultaneous detection of duck hepatitis a virus types 1 and 3, and of duck astrovirus type 1, by multiplex rt-pcr. | | 2014 | 24903592 |
| genetic characterization of a novel duck-origin picornavirus with six 2a proteins. | a novel virus was detected from diseased ducks and completely determined. the virus was shown to have a picornavirus-like genome layout. interestingly, the genome contained a total of up to six 2as, including four 2as (2a1-2a4) each having an npgp motif, an aig1-like 2a5, and a parechovirus-like 2a6. the 5'utr was predicted to possess a hepacivirus/pestivirus-like internal ribosome entry site (ires). however, the subdomain iiie consisted of a 3 nt stem and five unpaired bases, distinct from thos ... | 2014 | 24659102 |
| duck hepatitis a virus (dhav) genotype definition: comment on the article by cha et al. | duck hepatitis a virus (dhav) is genetically divided into three different genotypes: the original type dhav-1, a type recently isolated in taiwan (dhav-2), and a recently described type isolated in south korea and china (dhav-3). recently, cha et al. (2013) concluded that the existence that both dhav-1 and dhav-2 had been classified into one branch, with dhav genotype 3 (dhav-3) in another, and that the phylogenetic distance unit showed was 0.5, a tremendous value. however, there might be some c ... | 2014 | 24636163 |
| apoptosis induction in duck tissues during duck hepatitis a virus type 1 infection. | to investigate the role of apoptosis in duck viral hepatitis pathogenesis, 4- and 21-d-old ducks were inoculated with duck hepatitis a virus serotype 1 and killed at 2, 6, 12, 24, and 48 h postinfection. tdt-mediated dutp nick-end labeling was used to detect apoptosis cells. expression profiles of apoptosis-related genes including caspase-3, -8, -9, and bcl-2 in spleen, bursa of fabricius, liver, and the quantity of virus in blood were examined using real-time pcr. the tdt-mediated dutp nick-end ... | 2014 | 24604844 |
| bush sophora root polysaccharide and its sulfate can scavenge free radicals resulted from duck virus hepatitis. | in order to study the antioxidant effect of bush sophora root polysaccharide (bsrps) and its sulfate on anti-duck virus hepatitis (dvh), sulfated bush sophora root polysaccharide (sbsrps) was prepared by chlorosulfonic acid-pyridine method. ducklings were fed with bsrps and sbsrps after challenged dhav. death was monitored, evaluation indexes of peroxidative and hepatic injury at the initial (4th and 8th hour) and later (54th hour) stages were detected. the results showed a fine treatment effect ... | 2014 | 24582875 |
| comparison of bush sophora root polysaccharide and its sulfate's anti-duck hepatitis a virus activity and mechanism. | in order to research the sulfating modification in enhancing the anti-duck hepatitis a virus (dhav) activity of bush sophora root polysaccharide (bsrps), sulfated bush sophora root polysaccharide (sbsrps) was prepared by chlorosulfonic acid-pyridine method. kbr pellets method was applied to analyze their different structures. anti-dhav activity was studied by duck embryonic hepatocytes culture in vitro and artificial inoculation method in vivo. direct immunofluorescence method and real-time pcr ... | 2014 | 24507289 |
| dna methylation and regulation of the cd8a after duck hepatitis virus type 1 infection. | cluster of differentiation 8 (cd8) is expressed in cytotoxic t cells, where it functions as a co-receptor for the t-cell receptor by binding to major histocompatibility complex class i (mhci) proteins, which present peptides on the cell surface. cd8a is critical for cell-mediated immune defense and t-cell development. cd8a transcription is controlled by several cis-acting elements and trans-acting elements and is also regulated by dna methylation. however, the epigenetic regulation of cd8a in th ... | 2014 | 24505360 |
| [sequence analysis of vp1 gene of the duck hepatitis a virus type 3 strains isolated from shandong province of china in 2012]. | to reveal the genetic variation of the viral protein 1 (vp1) gene of the duck hepatitis a virus type 3 (dhav-3), the vp1 gene of 13 virulent dhav-3 strains isolated from shandong province of china in 2012 were amplified by rt-pcr, sequenced and analyzed. the results showed that all the vp1 genes of the 13 isolates contained 720 nucleotides encoding 240 amino acids, and shared with nucleotide identities of 94. 6%-99.9% and amino acid identities of 95.0%-100%. the nucleotide and amino acid sequenc ... | 2013 | 24386841 |
| virus isolate from carp: genetic characterization reveals a novel picornavirus with two aphthovirus 2a-like sequences. | picornaviruses have been isolated from a variety of hosts, mainly mammals and birds. here, we describe the sequence analysis of carp picornavirus 1 (cpv-1) f37/06 that was isolated from an organ pool (heart, brain, liver) of a common carp (cyprinus carpio). this carp perished after an accidental discharge of liquid manure into a fish pond and presented without obvious clinical symptoms. experimental intraperitoneal infection of young carp with cpv-1 revealed no clinical signs, but the virus was ... | 2014 | 24337965 |
| rapid detection of duck hepatitis a virus genotype c using reverse transcription loop-mediated isothermal amplification. | a one-step reverse transcription loop-mediated isothermal amplification (rt-lamp) assay was used and optimized to develop a rapid and sensitive detection system for duck hepatitis a virus genotype c (dhav-c) rna. a set of four specific primers was designed against highly conserved sequences located within the 3d gene from dhav (strain gx1201). under optimal reaction conditions, the sensitivity of dhav-c-specific rt-lamp was 100-fold higher than that of reverse transcriptase-polymerase chain reac ... | 2014 | 24291148 |
| effect of age on the pathogenesis of dhv-1 in pekin ducks and on the innate immune responses of ducks to infection. | duck hepatitis virus (dhv) affects 1-week-old but not 3-week-old ducks, and it causes a more severe disease in the younger ducks. these differences may be partially due to the host response to dhv infection. in order to understand this difference, we characterized the pathobiology of and innate immune response to dhv infection in 1-day-old (1d) and 3-week-old (3 w) ducks. viral rna was detected in duck livers at 24, 36 and 72 h after inoculation with dhv at a dose of 10(3) ld50. virus-induced pa ... | 2014 | 24162826 |
| genetic characterization of duck hepatitis a viruses isolated in china. | in recent years, the spread of duck hepatitis a viruses (dhavs) has represented a serious threat and significant economic impact in duck industry of china. the sixteen reported dhav isolates (15 dhav-1 strains and one dhav-3) were identified from infected ducks with clinical symptoms in china between 2009 and 2012. in the present study, the virulence of these viruses and complete sequences of the virion protein 1 (vp1) genes of the 16 dhavs were characterized. the median embryonic lethal doses ( ... | 2013 | 24144860 |
| identification and expression analysis of the leukocyte cell-derived chemotaxin-2 (lect2) gene in duck (anas platyrhynchos). | leukocyte cell-derived chemotaxin 2 (lect2), first identified as a chemotactic factor, is involved in the regulation of liver regeneration, carcinogenesis, and natural killer t-cell homeostasis in mammals. the function of lect2 in the duck remains unclear, however. a suppression subtractive cdna library was constructed from the livers of 3-day-old ducklings treated with duck hepatitis virus type i (dhv-1). a total of 66 expressed sequence tags (ests) were identified in the libraries. among the n ... | 2014 | 24076354 |
| transcriptome analysis of duck liver and identification of differentially expressed transcripts in response to duck hepatitis a virus genotype c infection. | duck is an economically important poultry and animal model for human viral hepatitis b. however, the molecular mechanisms underlying host-virus interaction remain unclear because of limited information on the duck genome. this study aims to characterize the duck normal liver transcriptome and to identify the differentially expressed transcripts at 24 h after duck hepatitis a virus genotype c (dhav-c) infection using illumina-solexa sequencing. | 2013 | 23923051 |
| complete genome sequence of a duck hepatitis a virus 1 isolated from a pigeon in china. | we report here the complete genome sequence of a duck hepatitis a virus 1 (dhav-1), strain fj1220, isolated from a dead pigeon in eastern china. dhav-1 fj1220 has high homology of up to 99.6% to the dhav-1 strain du/ch/lgd/111238 but relatively low homology to strains ffz05 and fz05. an amino acid hypervariable region in the vp1 protein of fj1220 has the motif (180)tpsgr(184) replaced by (180)alsrg(184) compared to strains ffz05 and fz05. | 2013 | 23846267 |
| improved duplex rt-pcr assay for differential diagnosis of mixed infection of duck hepatitis a virus type 1 and type 3 in ducklings. | infection with duck hepatitis a virus (dhav) causes an acute, rapidly spreading, and fatal disease of young ducklings. dhav type 1 (dhav-1) and type 3 (dhav-3) have been identified in china. in this study, a duplex rt-pcr assay was developed to identify dhav-1 and dhav-3 with mixed infection. the method was shown to be high specificity and sensitivity. the minimum detection limit of the method has been determined to be 10pg total rna templates extracted from duck liver samples or 10² copies vira ... | 2013 | 23624117 |
| high yield expression of duck hepatitis a virus vp1 protein in escherichia coli, and production and characterization of polyclonal antibody. | vp1 protein, the capsid protein of duck hepatitis a virus (dhav), contains critical epitopes for inducing a protective immune response. due to its low-level expression in escherichia coli (e. coli), the function of this protein is poorly characterized. in this study, a codon-optimized vp1 gene was chemically synthesized in terms of the codon usage bias in e. coli and subcloned into pet32a (+) to increase its expression. the recombinant vp1 fusion protein was purified from inclusion body by ni(2+ ... | 2013 | 23583731 |
| development and application of a universal taqman real-time pcr for quantitation of duck hepatitis b virus dna. | to develop a quantitative assay for universal detection of duck hepatitis b virus (dhbv) dna, a taqman real-time fluorescent quantitative polymerase chain reaction (fq-pcr) assay was developed using primers and probes based on genomic sequences located at nucleotide 241-414 of the dhbv core region which possesses the highest homology among the 44 dhbv genomes available in genbank. the dhbv core gene cloned in pgem-t was used to generate dhbv dna standard. the assay had a lowest detection limit o ... | 2013 | 23557670 |
| an experimental study of the pathogenicity of a duck hepatitis a virus genotype c isolate in specific pathogen free ducklings. | duck hepatitis a virus genotype c (dhav-c), recognized recently, is one of the pathogens causing fatal duck viral hepatitis in ducklings, especially in asia. to demonstrate the pathogenesis of the dhav-c isolate, 3-day-old specific pathogen free ducklings were inoculated subcutaneously with a dhav-c isolate and the clinical signs were observed. virus distribution, histological and apoptotic morphological changes of various tissues were examined at different times post inoculation. the serial, ch ... | 2012 | 23237375 |
| [overview on duck virus hepatitis a]. | 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. | 2012 | 23167191 |
| complete genome sequence of a duck hepatitis a virus type 3 identified in eastern china. | we report here the complete genome sequence of a novel duck hepatitis a virus type 3 (dhav-3) isolated from a dead cherry valley duckling in eastern china. the whole genomic nucleotide sequence and polyprotein amino acid sequence of the virus had higher homology with those of chinese dhav-3 isolates, medium homology with those of korean dhav-3 isolates, and the lowest homology with those of vietnamese isolate dn2. the result indicated that the genetic evolution of dhav-3 isolates had obvious geo ... | 2012 | 23166253 |
| complete genome sequence of a novel duck hepatitis a virus discovered in southern china. | we report here the complete genomic sequence of a novel duck hepatitis a virus (dhav) isolated from mixed infections with dhav type 1 (dhav-1) and dhav-3 in ducklings in southern china. the whole nucleotide sequence had the highest homology with the sequence of dhav-3 (genbank accession number dq812093) (96.2%). to our knowledge, this is the first report of gene rearrangement between dhav-1 and dhav-3, and it will help to understand the epidemiology and molecular characteristics of duck hepatiti ... | 2012 | 22923805 |
| 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 teste ... | 2012 | 22899433 |
| development and application of a reverse transcription loop-mediated isothermal amplification method for rapid detection of duck hepatitis a virus type 1. | we developed and evaluated a reverse transcription loop-mediated isothermal amplification (rt-lamp) assay for detecting duck hepatitis a virus type 1 (dhav-1). the amplification could be finished in 1 h under isothermal conditions at 63 °c by employing a set of four primers targeting the 2c gene of dhav-1. the rt-lamp assay showed higher sensitivity than the rt-pcr with a detection limit of 0.1 eld(50) 0.1 ml(-1) of dhav-1. the rt-lamp assay was highly specific; no cross-reactivity was observed ... | 2012 | 22869367 |
| development of a real-time quantitative pcr for detecting duck hepatitis a virus genotype c. | recently, duck hepatitis a virus genotype c (dhav-c), a causative agent of duck viral hepatitis, has been responsible for increasing economic losses in the duck industry in china and south korea. in this study, a real-time pcr assay targeting the 2c gene for detecting dhav-c was developed. the assay was confirmed to be specific and sensitive, and the minimum detection limit was 3.36 × 10(3) copies per reaction, making this assay suitable for rapid diagnosis of dhav-c infection from clinical samp ... | 2012 | 22855514 |
| protective immune responses in ducklings induced by a suicidal dna vaccine of the vp1 gene of duck hepatitis virus type 1. | a suicidal dna vaccine based on a semliki forest virus (sfv) replicon was evaluated for the development of a vaccine against duck hepatitis virus type 1 (dhv-1). the vp1 gene of dhv-1 was cloned and inserted into psca1, an sfv dna-based replicon vector. the resultant plasmid, psca/vp1, was transfected into bhk-21 cells and the antigenicity of the expressed protein was confirmed using an indirect immunofluorescence and western blot assay. immunogenicity was studied in ducklings. ducklings were in ... | 2012 | 22819169 |
| complete genome comparison of duck hepatitis virus type 1 parental and attenuated strains. | two complete duck hepatitis virus type 1 (dhv-1) genomes, strain sy5 and its chicken embryos passage descendent vaccine strain zj-a, were compared and analyzed in order to identify possible sites of attenuation. of the 205 nucleotide changes, 22 resulted in sense mutations, 174 produced nonsense mutations. besides, there are 7 consistent nucleotides substitutions in 5'utr and 2 in 3'utr. three of these 22 sense mutations resided in vp0, 6 exists in vp1, one exists in vp3, 3 exists in 2a2, 3 exis ... | 2012 | 22723199 |
| establishment of a duck cell line susceptible to duck hepatitis virus type 1. | until recently, there was no cell line that could produce continuously high-titer duck hepatitis virus type 1 (dhv-1). in this study, a duck embryo fibroblast (def) cell line was established, and the susceptibility of this cell line to dhv-1 was determined. the primary culture of def cells was from a duck embryo that was partially digested with trypsin. digested tissue pieces were cultured at 37°c in dulbecco's modified eagle medium supplemented with 10% fetal bovine serum. the cultured def cell ... | 2012 | 22633926 |
| rapid detection of duck hepatitis virus type-1 by reverse transcription loop-mediated isothermal amplification. | a reverse transcription loop-mediated isothermal amplification (rt-lamp) assay for the detection of duck hepatitis virus type-1 (dhv-1) was established. using primers specific to the highly conserved 3d gene of dhv-1, the developed rt-lamp assay detected the viral rna of dhv-1 extracted from both allantoic fluid and liver samples of infected ducks. the assay is as sensitive as rt-pcr, and shows no cross-reaction with other common avian viral and bacterial pathogens. in addition to detection via ... | 2012 | 22465103 |
| cytokine gene expression in the livers of ducklings infected with duck hepatitis virus-1 jx strain. | duck hepatitis virus type 1 (dhv-1) causes a highly contagious disease in ducklings and is often associated with liver necrosis, hemorrhages, and high mortality. in the current study, the expression levels of gene transcripts encoding proinflammatory cytokines and the virus were measured by quantitative reverse-transcription pcr in duck livers after infection with a dhv-1 jx isolate obtained from natural cases in hubei province, china. in addition, sera il-1β, il-6, and alanine aminotransferase ... | 2012 | 22334733 |
| a multiplex pcr for detection of six viruses in ducks. | in this study, six pairs of specific primers that can amplify dna fragments of different sizes were designed and synthesized according to viral protein gene sequences published in genbank. then, a multiplex pcr method was established for rapid detection of duck hepatitis virus 1, duck plague virus, duck tembusu virus, muscovy duck parvovirus, muscovy duck reovirus, and duck h9n2 avian influenza virus, and achieve simple and rapid detection of viral diseases in ducks. single pcr was used to confi ... | 2017 | 28728835 |
| host differences affecting resistance and susceptibility of the second generation of a pekin duck flock to duck hepatitis a virus genotype 3. | earlier work suggested the possibility to anti duck hepatitis a virus genotype 3 (dhav-3) using the resistance breeding strategy. here, we report the creation of the second generations of a resistant pekin duck flock (designated z8r2) and a highly susceptible pekin duck flock (designated z8s2) and the investigation of their responses to dhav-3. experimental infection with dhav-3 at 7 days of age resulted in a high mortality (66.3%) in 11 susceptible z8s2 families and an extremely low mortality r ... | 2017 | 28674528 |
| raw rehmannia radix polysaccharide can effectively release peroxidative injury induced by duck hepatitis a virus. | duck viral hepatitis (dvh), caused by duck hepatitis a virus (dhav), is a fatal contagious infectious disease which spreads rapidly with high morbidity and high mortality, and there is no effective clinical drug against dvh. | 2017 | 28638862 |