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1.
Avian Pathol ; : 1-26, 2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32208867

RESUMO

Waterfowl parvoviruses (WPVs) including goose parvovirus (GPV), novel goose parvovirus-related virus (NGPV) and Muscovy duck parvovirus (MDPV) cause significant economic losses and epizootic threat to the waterfowl industries and little is known about the B-cell epitope of WPVs. In this study, a monoclonal antibody (mAb) 5B5 against the VP3 protein of NGPV was used to identify the possible epitope in the three kinds of WPVs. The mAb 5B5 had neutralizing activities to the three viruses, and reacted with the conserved linear B-cell epitopes of 438LHNPPP443 in VP3 protein of GPV, NGPV and MDPV. To the author's best knowledge, this appears to be the first report on identification of the common conserved neutralizing linear B-cell epitope on VP3 protein of three different WPVs, which would facilitate the development of a novel immunodiagnostic assay for rapid detection of WPVs infection.

2.
Vet Microbiol ; 240: 108542, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31902499

RESUMO

Influenza A virus (IAV) and bacteria co-infection can influence the host clinical conditions. Both H9N2 IAV and Pseudomonas aeruginosa (P. aeruginosa) are potential pathogens of respiratory diseases in mink. In this study, to clarify the effects of H9N2 IAV and P. aeruginosa co-infections on hemorrhagic pneumonia in mink, we carried out to establish the mink models of the two-pathogen co-infections in different orders. Compared with the single infections with H9N2 IAV or P. aeruginosa, the mink co-infected with H9N2 IAV and P. aeruginosa showed severe respiratory diseases, and exacerbated histopathological lesions and more obvious apoptosis in the lung tissues. H9N2 IAV shedding and viral loads in the lungs of the mink co-infected with H9N2 IAV and P. aeruginosa were higher than those in the mink with single H9N2 IAV infection. Furthermore, the clearance of P. aeruginosa in the co-infected mink lungs was delayed. In addition, the anti-H9N2 antibody titers in mink with P. aeruginosa co-infection following H9N2 IAV infection were significantly higher than those of the other groups. This implied that H9N2 IAV and P. aeruginosa co-infection contributed to the development of hemorrhagic pneumonia in mink, and that P. aeruginosa should play a major role in the disease. The exact interaction mechanism among H9N2 IAV, P. aeruginosa and the host needs to be further investigated.

3.
Animals (Basel) ; 9(12)2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31810309

RESUMO

Duck astrovirus type 1 (DAstV-1) infection constitutes a cause of viral hepatitis in ducklings and little is known about the B-cell epitope of DAstV-1. In this study, a monoclonal antibody (mAb) 3D2 against open reading frame 2 (ORF2) protein of DAstV-1 was used to identify the possible epitope in the four serotypes of DAstV. The mAb 3D2 showed no neutralization activity to DAstV-1, and reacted with the conserved linear B-cell epitopes of 454STTESA459 in DAstV-1 ORF2 protein. Sequence analysis, dot blot assay, and cross-reactivity test indicated that the epitope peptide was highly conserved in DAstV-1 sequence and mAb 3D2 had no cross-reactivity with other DAstV serotypes. To the best of our knowledge, this is the first report about identification of the specific conserved linear B-cell epitope of DAstV-1, which will facilitate the serologic diagnosis of DAstV-1 infection.

4.
Int J Mol Sci ; 20(24)2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31817666

RESUMO

Autophagy is a tightly regulated catabolic process and is activated in cells in response to stress signals. Despite extensive study, the interplay between duck hepatitis A virus type 1 (DHAV-1) and the autophagy of host cells is not clear. In this study, we applied proteomics analysis to investigate the interaction mechanism between DHAV-1 and duck embryo fibroblast (DEF) cells. In total, 507 differentially expressed proteins (DEPs) were identified, with 171 upregulated proteins and 336 downregulated proteins. The protein expression level of heat shock proteins (Hsps) and their response to stimulus proteins and zinc finger proteins (ZFPs) were significantly increased while the same aspects of ribosome proteins declined. Bioinformatics analysis indicated that DEPs were mainly involved in the "response to stimulus", the "defense response to virus", and the "phagosome pathway". Furthermore, Western blot results showed that the conversion of microtubule-associated protein 1 light chain 3-I (LC3-I) to the lipidation form of LC3-II increased, and the conversion rate decreased when DEF cells were processed with 4-phenylbutyrate (4-PBA). These findings indicated that DHAV-1 infection could cause endoplasmic reticulum (ER) stress-induced autophagy in DEF cells, and that ER stress was an important regulatory factor in the activation of autophagy. Our data provide a new clue regarding the host cell response to DHAV-1 and identify proteins involved in the DHAV-1 infection process or the ER stress-induced autophagy process.

5.
Vet Microbiol ; 239: 108496, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31767077

RESUMO

Duck circovirus (DuCV) has a small, single-stranded circular DNA genome of approximately 1.99 kb. Through a genome sequence analysis using the dottup program, we found that a quadruple tandem repeat sequence (QTR) in the intergenic region between the rep and cap genes of the DuCV genome, but not in other circoviruses. The QTR was also substantially different and evolutionarily conserved in the genotype 1 and 2 DuCV strains. Furthermore, a luciferase reporter assay demonstrated that QTR functioned as a downstream sequence element (DSE) of polyadenylation signals to enhance mRNA stability, which was dependent on four copies but not the QTR direction. Cap and Rep expression derived by subgenomic constructs also revealed a critical role of QTR in regulating viral gene expression. Finally, a reverse genetic study of a DuCV-based minicircle DNA technique found that a deletion of QTR induced a significant deficiency in viral genes transcription and replication. Our findings were the first to report that QTR only exists in the DuCV genome and serves as a novel molecular marker of DuCV genotyping, and has revealed its crucial biological function in regulating viral gene expression.


Assuntos
Circovirus/genética , Regulação Viral da Expressão Gênica/genética , Sequências de Repetição em Tandem/genética , Animais , Infecções por Circoviridae/virologia , DNA Viral/genética , Genoma Viral/genética , Genótipo , Estabilidade de RNA
6.
Biomolecules ; 9(10)2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31658691

RESUMO

As a disease characterized by severe liver necrosis and hemorrhage, duck viral hepatitis (DVH) is mainly caused by duck hepatitis A virus (DHAV). The positive-strand RNA genome of DHAV type 1 (DHAV-1) contains an internal ribosome entry site (IRES) element within the 5' untranslated region (UTR), structured sequence elements within the 3' UTR, and a poly(A) tail at the 3' terminus. In this study, we first examined that insulin-like growth factor-2 mRNA-binding protein-1 (IGF2BP1) specifically interacted with the DHAV-1 3' UTR by RNA pull-down assay. The interaction between IGF2BP1 and DHAV-1 3' UTR strongly enhanced IRES-mediated translation efficiency but failed to regulate DHAV-1 replication in a duck embryo epithelial (DEE) cell line. The viral propagation of DHAV-1 strongly enhanced IGF2BP1 expression level, and viral protein accumulation was identified as the key point to this increment. Collectively, our data demonstrated the positive role of IGF2BP1 in DHAV-1 viral proteins translation and provided data support for the replication mechanism of DHAV-1.

7.
Virol J ; 16(1): 112, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488178

RESUMO

BACKGROUND: Reverse genetics systems enable the manipulation of viral genomes and therefore serve as robust reverse genetic tools to study RNA viruses. A DNA-launched rescue system initiates the transcription of viral genomic cDNA from eukaryotic promoter in transfected cells, generating homogenous RNA transcripts in vitro and thus enhancing virus rescue efficiency. As one of the hazardous pathogens to ducklings, the current knowledge of the pathogenesis of duck astrovirus type 1 (DAstV-1) is limited. The construction of a DNA-launched rescue system can help to accelerate the study of the virus pathogenesis. However, there is no report of such a system for DAstV-1. METHODS: In this study, a DNA-launched infectious clone of DAstV-1 was constructed from a cDNA plasmid, which contains a viral cDNA sequence flanked by hammerhead ribozyme (HamRz) and a hepatitis delta virus ribozyme (HdvRz) sequence at both terminals of the viral genome. A silent nucleotide mutation creating a Bgl II site in the ORF2 gene was made to distinguish the rescued virus (rDAstV-1) from the parental virus (pDAstV-1). Immunofluorescence assay (IFA) and western blot were conducted for rescued virus identification in duck embryo fibroblast (DEF) cells pre-treated with trypsin. The growth characteristics of rDAstV-1 and pDAstV-1 in DEF cells and the tissue tropism in 2-day-old ducklings of rDAstV-1 and pDAstV-1 were determined. RESULTS: The infectious DAstV-1 was successfully rescued from baby hamster kidney (BHK-21) cells and could propagate in DEF cells pre-treated with 1 µg/ml trypsin. Upon infection of DEF cells pre-treated with trypsin, DAstV-1 mRNA copies were identified after serial passaging, and the result showed that rDAstV-1 and pDAstV-1 shared similar replication kinetics. Animal experiment showed that the rDAstV-1 had an extensive tissue tropism, and the virus was capable of invading both the central and the peripheral immune organs in infected ducklings. CONCLUSIONS: An improved DNA-launched reverse genetics system for DAstV-1 was firstly constructed. Infectious virus recovered from BHK-21 cells could propagate in DEF cells pre-treated with trypsin. This is the first report of the successful in vitro cultivation of DAstV-1. We believe this valuable experimental system will contribute to the further study of DAstV-1 genome function and pathogenesis.


Assuntos
Infecções por Astroviridae/veterinária , Avastrovirus/genética , Avastrovirus/isolamento & purificação , Patos/virologia , Genética Reversa/métodos , Cultura de Vírus/métodos , Animais , Infecções por Astroviridae/virologia , Avastrovirus/crescimento & desenvolvimento , Linhagem Celular , Clonagem Molecular , DNA Complementar/genética , Genoma Viral , Plasmídeos , RNA Viral/genética , Transfecção , Tropismo Viral , Vírion/genética
8.
Virus Res ; 270: 197670, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31330206

RESUMO

The nuclear localization signals (NLS) were usually composed of basic residues (K and R) and played an important role in delivery of genomes and structural protein into nucleus. In this research, we identified that 3Dpol/3CD entered into nucleus during viral propagation of duck hepatitis A virus type 1 (DHAV-1). To investigate the reason that 3Dpol/3CD entered into nucleus, the amino acid sequence of 3CD was analyzed through NLS Mapper program. The basic region 17PRKTAYMRS25 was subsequently proved to be a functional NLS to guide 3Dpol/3CD into nucleus. 18R, 19K and 24R were found essential for maintaining the nuclear targeting activity, and exchange between 24R and 24K had no impact on cellular localization of 3Dpol. Since the entry of 3Dpol/3CD into nucleus was essential for shutoff of host cell transcription and maintaining the viral propagation of picornavirus numbers, our study provided new insights into the mechanism of DHAV-1 propagation.

9.
Vaccine ; 37(31): 4364-4369, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31227355

RESUMO

Duck hepatitis A virus (DHAV) is the major pathogen of duck viral hepatitis, which has caused great economic losses to duck breeding industry. As an effective delivery tool for protein antigens, Lactococcus lactis (L. lactis) has been successfully used to stimulate mucosal and systemic immune response. In this study, a recombinant L. lactis named NZ3900-VP1 was constructed, which could express VP1 protein of DHAV type 3 (DHAV-3) by using a nisin-controlled expression (NICE) system. The animal experiment in both mice and ducklings were performed to detect the immune response and protection effect of oral vaccination by the recombinant L. lactis. The results showed that oral vaccination with L. lactis NZ3900-VP1 significantly induced specific anti-VP1 IgG antibodies and mucosal secretory immunoglobulin A (sIgA) of DHAV-3 in mice and ducklings, and cytokines including interleukin-2 (IL-2), interferon gamma (IFN-γ), interleukin-10 (IL-10) and interleukin-4 (IL-4). Notably, the ducklings vaccinated with L. lactis NZ3900-VP1 were effectively protected when facing natural infestation of DHAV-3, which indicated that the recombinant L. lactis could serve as an effective vaccine to prevent DHAV-3 infection in ducklings.

10.
Vet Res ; 50(1): 17, 2019 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-30819249

RESUMO

Porcine circovirus-associated disease (PCVAD) is one of the most serious infectious diseases in pigs worldwide. The primary causative agent of PCVAD is porcine circovirus type 2 (PCV2), which can cause lymphoid depletion and immunosuppression in pigs. Our previous study demonstrated that Laiwu (LW) pigs, a Chinese indigenous pig breed, have stronger resistance to PCV2 infection than Yorkshire × Landrace (YL) pigs. In this study, we found that the YL pigs showed more severe lymphocyte apoptosis and higher viral load in the spleen tissue than LW pigs. To illustrate the differential gene expression between healthy and infected spleens, transcriptome profiling of spleen tissues from PCV2-infected and control YL pigs was compared by RNA sequencing. A total of 90 differentially expressed genes (DEGs) was identified, including CD207, RSAD2, OAS1, OAS2, MX2, ADRB3, CXCL13, CCR1, and ADRA2C, which were significantly enriched in gene ontology (GO) terms related to the defense response to virus and cell-cell signaling, and another nine DEGs, KLF11, HGF, PTGES3, MAP3K11, XDH, CYCS, ACTC1, HSPH1, and RYR2, which were enriched in GO terms related to regulation of cell proliferation or apoptosis. Among these DEGs, the CXCL13 gene, which can suppress lymphocyte apoptosis during PCV2 infection, was significantly down-regulated in response to PCV2 infection in YL but not in LW pigs. By analysis of the regulatory elements in the promoter and 3'-untranslated region (3'-UTR) of porcine CXCL13, we found that the single nucleotide polymorphism (SNP) -1014 G (LW) > A (YL) and the Sus scrofa microRNA-296-5p (ssc-miR-296-5p) participated in regulating CXCL13 expression during the response to PCV2 infection.


Assuntos
Apoptose , Quimiocina CXCL13/metabolismo , Infecções por Circoviridae/veterinária , Circovirus , Linfócitos/virologia , Baço/virologia , Doenças dos Suínos/virologia , Animais , Western Blotting/veterinária , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/metabolismo , Infecções por Circoviridae/virologia , Circovirus/metabolismo , DNA Viral/genética , Citometria de Fluxo/veterinária , Perfilação da Expressão Gênica/veterinária , Regulação Viral da Expressão Gênica , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Análise de Sequência de RNA/veterinária , Baço/metabolismo , Baço/patologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/metabolismo , Carga Viral/veterinária
11.
Virology ; 528: 101-109, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30590261

RESUMO

Duck virus hepatitis (DVH) caused by duck hepatitis A virus type 1 (DHAV-1) is an acute and highly contagious disease affecting young ducklings. The VP1 protein is one of the major structural proteins of DHAV-1 carries critical epitopes responsible for the induction of neutralizing antibodies. In this study, we have successfully constructed an immune phage display VHHs library against DHAV-1 with the size of 6 × 106 colonies. A nanobody (Nb) against VP1 protein of DHAV-1, named Nb25, was identified from the immunized phage display library. Nb25 could react with the conserved linear B-cell epitope of 174PAPTST179 in DHAV-1 VP1, even though Nb25 showed no neutralizing activity to DHAV-1. To the best of our knowledge, this is the first report about preparation of anti-DHAV-1 Nbs and identification of the specific conserved linear B-cell epitope of DHAV-1 with Nb, which will facilitate the serologic diagnosis of DHAV-1 infection.


Assuntos
Epitopos de Linfócito B/imunologia , Vírus da Hepatite do Pato/imunologia , Anticorpos de Domínio Único/isolamento & purificação , Proteínas Estruturais Virais/imunologia , Animais , Técnicas de Visualização da Superfície Celular , Patos , Hepatite Viral Animal/diagnóstico , Hepatite Viral Animal/imunologia , Doenças das Aves Domésticas/virologia
12.
Front Microbiol ; 9: 2250, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30319572

RESUMO

The duck hepatitis A virus type 1 (DHAV-1) is a member of Picornaviridae family, the genome of the virus contains a 5' untranslated region (5' UTR), a large open reading frame that encodes a polyprotein precursor and a 3' UTR followed by a poly(A) tail. The translation initiation of virus proteins depends on the internal ribosome-entry site (IRES) element within the 5' UTR. So far, little information is known about the role of the 3' UTR and poly(A) tail during the virus proliferation. In this study, the function of the 3' UTR and poly(A) tail of DHAV-1 in viral replication and IRES-mediated translation was investigated. The results showed that both 3' UTR and poly(A) tail are important for maintaining viral genome RNA stability and viral genome replication. During DHAV-1 proliferation, at least 20 adenines were required for the optimal genome replication and the virus replication could be severely impaired when the poly (A) tail was curtailed to 10 adenines. In addition to facilitating viral genome replication, the presence of 3' UTR and poly(A) tail significantly enhance IRES-mediated translation efficiency. Furthermore, 3' UTR or poly(A) tail could function as an individual element to enhance the DHAV-1 IRES-mediated translation, during which process, the 3' UTR exerts a greater initiation efficiency than the poly(A)25 tail.

13.
Vet Microbiol ; 221: 33-37, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29981705

RESUMO

Generally, duck hepatitis A virus type 1 (DHAV-1) only infects young ducklings. Since December 2016, severe outbreaks of duck viral infection with egg drop, feed consumption decline, and ovary-oviduct disease have occurred in some laying duck flocks in Shandong Province of China. DHAV-1 isolated from the affected ducks was confirmed as the causative pathogen of the egg drop. Compared with other DHAV-1 strains, the novel isolate has three special amino acid mutation points in the most variable regions at the C-terminus of VP1. The experimental infection in laying ducks indicated that successful immunization with DHAV-1 vaccine could protect laying duck from infection. To the best of our knowledge, this is the first reported incidence of a severe duck disease outbreak involving egg drop syndrome caused by DHAV-1.


Assuntos
Surtos de Doenças/veterinária , Patos , Vírus da Hepatite A/classificação , Hepatite A/veterinária , Doenças das Aves Domésticas/virologia , Animais , China/epidemiologia , Feminino , Hepatite A/patologia , Hepatite A/virologia , Oviductos/patologia , Oviductos/virologia , Oviposição , Filogenia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/patologia
14.
Vet Microbiol ; 216: 7-12, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29519528

RESUMO

Three parvoviruses were isolated from the raccoon dogs experiencing severe enteritis, named RDPV-DP1, RDPV-DP2 and RDPV-DP3, respectively. The VP2 genes of the 3 isolates showed 99.9% identity at the nucleotide level, and shared 99.1%-99.5% identity with the reference CPVs. The RDPVs resembled original CPV-2, but with four mutations. The RDPVs displayed S297A of VP2 protein as CPV-2a or CPV-2b prevalent throughout most of the world. Residue N375D was found in the 3 isolates, resembling CPV-2a/2b/2c. And the 3 isolates had a natural mutation of VP2 residue V562L, which is adjacent to residue 564 and 568 and might be involved in host range. Interestingly, VP2 S27T was firstly found in the isolates. Phylogenetic analysis of VP2 genes revealed that the RDPVs were clustered into one small evolutionary branch and shared the identical branch with 7 CPV-2 isolates from raccoon dogs and one CPV-2 isolate from fox, not with CPV vaccine viruses. Phylogenetic analysis of NS1 genes demonstrated that the RDPVs shared the identical branch with the reference CPV-2a/2b/2c. Experimental infection showed that RDPV infection caused a high morbidity in raccoon dogs. It implied that the RDPV was virulent to raccoon dogs and continued to evolve in China.


Assuntos
Infecções por Parvoviridae/veterinária , Parvovirus Canino/genética , Parvovirus Canino/patogenicidade , Animais , Proteínas do Capsídeo/genética , China/epidemiologia , Doenças do Cão/epidemiologia , Doenças do Cão/virologia , Cães , Variação Genética , Especificidade de Hospedeiro , Mutação , Infecções por Parvoviridae/epidemiologia , Infecções por Parvoviridae/fisiopatologia , Infecções por Parvoviridae/virologia , Parvovirus Canino/isolamento & purificação , Filogenia , Cães Guaxinins , Análise de Sequência de DNA
15.
Vet Microbiol ; 214: 21-27, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29408028

RESUMO

Duck circovirus (DuCV) is divided into genotypes 1 and 2. The DuCV ORF3 protein is a newly identified viral protein with apoptotic activity. In this study, the differences in the gene sequences, subcellular localization, and apoptotic activities of the ORF3 proteins of DuCV genotypes 1 and 2 were analyzed. A T-to-A point mutation at nucleotide 236 (T236A) in the ORF3 gene sequence of DuCV genotype 1 was observed, which generates a premature stop codon (TAG) and resulted in a truncated ORF3 protein. The ORF3 protein of DuCV genotype 2 is 20 amino acids longer at its C-terminus than the truncated ORF3 protein of genotype 1. A variant monopartite-type nuclear localization signal (RRLRTCNCRACRTLK) was identified within the C-terminal region of the ORF3 protein of DuCV genotype 2, which is essential for the nuclear localization of the protein. The 20 C-terminal residues of the DuCV genotype 2 ORF3 protein also inhibits the apoptotic activity of the protein. Our findings provide insight into the biological and functional characteristics of the DuCV ORF3 protein.


Assuntos
Apoptose/genética , Circovirus/genética , Regulação Viral da Expressão Gênica , Sinais de Localização Nuclear/genética , Fases de Leitura Aberta/genética , Proteínas Virais/genética , Animais , Núcleo Celular , Infecções por Circoviridae/virologia , DNA Viral/genética , Patos/virologia , Genoma Viral , Genótipo , Filogenia
16.
Virol J ; 14(1): 212, 2017 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-29100535

RESUMO

BACKGROUND: DNA-launched infectious system is a useful tool with high rescue efficiency that allows the introduction of mutations in specific positions to investigate the function of an individual viral element. Rescued virus particles could be harvested by directly transfecting the DNA-launched recombinant plasmid to the host cells, which will reduce labor and experimental cost by skipping the in vitro transcription assay. METHODS: A total of four overlapping fragments covering the entire viral genome were amplified and then were assembled into a transformation vector based on pIRES2-EGFP to establish the DNA-launched infectious system of duck hepatitis A virus type 1 (DHAV-1), named pIR-DHAV-1. Reverse transcription polymerase chain reaction (RT-PCR) detection, quantitative real-time polymerase chain reaction (qRT-PCR), western blotting assay and indirect immunofluorescence (IFA) were conducted for rescued virus identification. A total of 4.0 µg of recombinant plasmid of pIR-DHAV-1 and in vitro transcribed product of 4.0 µg of RNA-launched infectious clone named pR-DHAV-1 were transfected into BHK-21 cells to analyze the rescue efficiency. Following that, tissue tropism of rescued virus (rDHAV-1) and parental virus (pDHAV-1) were assayed for virulence testing in 1-day-old ducklings. RESULTS: Rescued virus particles carry the designed genetic marker which could be harvested by directly transfecting pIR-DHAV-1 to BHK-21 cells. The qRT-PCR and western blotting results indicated that rDHAV-1 shared similar growth characteristics with pDHAV-1. Furthermore, DNA-launched infectious system possessed much higher rescue efficiency assay compared to RNA-launched infectious system. The mutation at position 3042 from T to C has no impact on viral replication and tissue tropism. From 1 h post infection (hpi) to 48 hpi, the viral RNA copies of rDHAV-1 in liver were the highest among the six tested tissues (with an exception of thymus at 6 hpi), while the viral RNA copy numbers in heart and kidney were alternately the lowest. CONCLUSION: We have constructed a genetically stable and highly pathogenic DNA-launched infectious clone, from which the rescued virus could be harvested by direct transfection with recombinant plasmids. rDHAV-1 shared similar growth characteristics and tissue tropism with pDHAV-1. The DNA-launched infectious system of DHAV-1 possessed higher rescue efficiency compared to the traditional RNA-launched infectious system.


Assuntos
Vírus da Hepatite do Pato/crescimento & desenvolvimento , Vírus da Hepatite do Pato/isolamento & purificação , Hepatite Viral Animal/virologia , Infecções por Picornaviridae/virologia , Cultura de Vírus/métodos , Animais , Linhagem Celular , DNA Viral/genética , Marcadores Genéticos , Vetores Genéticos/genética , Genoma Viral/genética , Vírus da Hepatite do Pato/genética , Infecções por Picornaviridae/veterinária , Transfecção , Vírion/genética
17.
J Virol Methods ; 249: 165-169, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28918072

RESUMO

Duck short beak and dwarfism syndrome (SBDS) is an emerging infectious disease caused by a novel goose parvovirus-related virus (NGPV) in China. Until now, it remains uncertain whether the Cherry Valley ducks and mule ducks with SBDS are co-infected with classical goose parvovirus (GPV) and NGPV. In this study, a duplex semi-nested PCR assay with high specificity and sensitivity was developed for detection of the two viruses. Using the duplex PCR assay, NGPV was tested positive in all the 15 duck flocks with SBDS, whereas classical GPV was not detected in all the 133 sick and dead ducks collected from East China. A total of 87 (91.58%) Cherry Valley ducks aged from 5 to 18days and 35 (92.11%) mule ducks aged from 17 to 25days were detected positive for NGPV. In the NGPV-positive ducks, the virus detection rates were 81.97% to 8.20% in heart, liver, spleen, lung, kidney, pancreas, bile, thymus, bursa of Fabricius, and brain. The results indicated that NGPV was prevalent in the duck flocks of East China, whereas classical GPV was not detected in Cherry Valley ducks and mule ducks with SBDS. NGPV has extensive tissue tropism in Cherry Valley duck and mule duck, which could invade both the central and peripheral immune organs and break through the blood-brain barrier of ducks.


Assuntos
Patos/virologia , Infecções por Parvoviridae/veterinária , Parvovirus/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Doenças das Aves Domésticas/virologia , Animais , Bico , Encéfalo/virologia , China/epidemiologia , Limite de Detecção , Infecções por Parvoviridae/diagnóstico , Infecções por Parvoviridae/epidemiologia , Infecções por Parvoviridae/virologia , Parvovirus/genética , Filogenia , Doenças das Aves Domésticas/diagnóstico , Doenças das Aves Domésticas/mortalidade , Sensibilidade e Especificidade , Síndrome , Tropismo Viral
18.
Sci Rep ; 7(1): 7429, 2017 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-28785024

RESUMO

H9N2 influenza A virus (IAV) causes low pathogenic respiratory disease and infects a wide range of hosts. In this study, six IAVs were isolated from mink and identified as H9N2 IAV. Sequence analysis revealed that the six isolates continued to evolve, and their PB2 genes shared high nucleotide sequence identity with H7N9 IAV. The six isolates contained an amino acid motif PSRSSR↓GL at the hemagglutinin cleavage site, which is a characteristic of low pathogenic influenza viruses. A serosurvey demonstrated that H9N2 IAV had spread widely in mink and was prevalent in foxes and raccoon dogs. Transmission experiments showed that close contact between H9N2-infected mink and naive mink, foxes and raccoon dogs resulted in spread of the virus to the contact animals. Furthermore, H9N2 challenge experiments in foxes and raccoon dogs showed that H9N2 IAV could infect these hosts. Virological and epidemiological surveillance of H9N2 IAV should be strengthened for the fur animal industry.


Assuntos
Transmissão de Doença Infecciosa , Vírus da Influenza A Subtipo H9N2/crescimento & desenvolvimento , Infecções por Orthomyxoviridae/veterinária , Motivos de Aminoácidos/genética , Animais , Anticorpos Antivirais/sangue , Raposas , Vírus da Influenza A Subtipo H9N2/classificação , Vírus da Influenza A Subtipo H9N2/genética , Vírus da Influenza A Subtipo H9N2/isolamento & purificação , Vison , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/virologia , RNA Replicase/genética , Guaxinins , Análise de Sequência de DNA , Estudos Soroepidemiológicos , Proteínas Virais/genética
19.
Vet Microbiol ; 205: 92-98, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28622870

RESUMO

Six feline panleukopenia viruses (FPV) were detected in the intestinal samples from the 176 mink collected in China during 2015 to 2016, named MEV-SD1, MEV-SD2, MEV-SD3, MEV-SD4, MEV-SD5 and MEV-SD6. The VP2 genes of the isolates shared 98.9%-100% identity with the reference sequences. The substitution of residue V300A in VP2 protein differentiates the isolates from the reference MEVs, and A300 is a characteristic of FPV. Furthermore, phylogenetic analysis of VP2 genes indicated that the six isolates were clustered into the same branch of all the reference FPVs. The NS1 genes of the isolates shared 98.2%-100% identity with the reference sequences. The NS1 genes of the six isolates and the three reference FPVs formed one unique evolutionary branch. To clarify the pathogenicity of the isolates, animal experiments were performed on healthy mink, using MEV-SD1. As a result, the morbidity of the inoculated animals was 100% and the mortality was as high as 38.9%. It was implied that the FPV infection caused a high morbidity and mortality in mink and the inoculation dose had an effect on pathogenicity of MEV-SD1 in mink.


Assuntos
Vírus da Panleucopenia Felina/classificação , Panleucopenia Felina/virologia , Animais , Gatos , China , Vírus da Panleucopenia Felina/genética , Vírus da Panleucopenia Felina/isolamento & purificação , Vírus da Panleucopenia Felina/patogenicidade , Vison , Filogenia
20.
Antonie Van Leeuwenhoek ; 110(4): 585-592, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28058577

RESUMO

Streptococcus suis is an important zoonotic pathogen causing infections in pigs and humans. Bacterial surface-related proteins are often explored as potential vaccine candidates and diagnostic antigens. In the present study, glutamate dehydrogenase, a highly conserved immunogenic extracellular protein, was used to establish a dot horseradish peroxidase enzyme-linked staphylococcal protein A immunosorbent assay (Dot-PPA-ELISA) for diagnosis of S. suis infection. The antigen-antibody reaction was optimised through checkerboard titration involving serial dilutions, followed by selective blocking tests and evaluations of cross-reaction, repeatability, and stability. Comparative analysis by using a conventional plate ELISA kit showed that the specificity and sensitivity of the Dot-PPA-ELISA were 97.5 and 96.6%, respectively. Furthermore, dynamic changes in the levels of antibody in rabbits immunised with a propolis inactivated vaccine were monitored by Dot-PPA-ELISA. A total seroprevalence of 73.1% in 305 pig serum samples indicated the method's applicability to detect S. suis infection. Cumulatively, the results suggested that Dot-PAA-ELISA is a convenient, rapid, sensitive, and specific diagnostic method suitable for studying large numbers of samples obtained from clinical and epidemiological studies, thereby helping reduce important economic losses.


Assuntos
Anticorpos Antibacterianos/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Glutamato Desidrogenase/imunologia , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/veterinária , Streptococcus suis/imunologia , Animais , Coelhos , Sensibilidade e Especificidade , Infecções Estreptocócicas/microbiologia
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