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1.
Arch Virol ; 164(11): 2837-2841, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31494776

RESUMO

Since January 2019, abnormal molting has been observed frequently in approximately 40-day-old Pekin ducks in China. To investigate the possible involvement of a virus, we tested the prevalence of duck circovirus (DuCV), goose hemorrhagic polyomavirus (GHPyV), and goose parvovirus (GPV) in 11 molt cases in two provinces. GPV was detected in all cases, particularly in all samples collected from the feather area. The complete genome sequences of three GPV strains were determined and found to have 52 nucleotide changes relative to GPVs associated with short beak and dwarfism syndrome of Pekin ducks. These data will enhance our understanding of GPV diversity and outcomes of GPV infection in Pekin ducks.


Assuntos
Patos/virologia , Gansos/virologia , Muda/fisiologia , Parvovirinae/isolamento & purificação , Doenças das Aves Domésticas/virologia , Animais , China/epidemiologia , Circovirus/genética , Circovirus/isolamento & purificação , Genoma Viral/genética , Parvovirinae/genética , Polyomavirus/genética , Polyomavirus/isolamento & purificação , Doenças das Aves Domésticas/epidemiologia
2.
BMC Vet Res ; 15(1): 271, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31370846

RESUMO

BACKGROUND: Fowl adenoviruses (FAdVs) are associated with many diseases, resulting in huge economic losses to the poultry industry worldwide. Since 2015, outbreaks of FAdV infections with high mortality rates have been reported in China. A continued surveillance of FAdVs contributes to understand the epidemiology of the viruses. RESULTS: We isolated 155 FAdV strains from diseased chickens from poultry in China between 2015 and 2018. PCR analysis determined that 123 samples were FAdV species C, 27 were FAdV species E, and five contained two different FAdV strains. The phylogenetic analysis demonstrates that these sequences of hexon regions were clustered into three distinct serotypes: FAdV-4 (79.4%, 123/155), FAdV-8a (13.5%, 21/155) and FAdV-8b (3.9%, 6/155), of which FAdV-4 was the dominant serotype in China. CONCLUSIONS: The characterization of newly prevalent FAdV strains provides valuable information for the development of an effective control strategy for FAdV infections in chickens.


Assuntos
Infecções por Adenoviridae/veterinária , Aviadenovirus/classificação , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/virologia , Infecções por Adenoviridae/epidemiologia , Infecções por Adenoviridae/prevenção & controle , Infecções por Adenoviridae/virologia , Animais , Aviadenovirus/isolamento & purificação , Galinhas , China/epidemiologia , Filogenia , Doenças das Aves Domésticas/prevenção & controle , Sorogrupo
3.
BMC Vet Res ; 15(1): 274, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31370852

RESUMO

BACKGROUND: In Poland, the leader in goose production in Europe, goose parovirus infection, or Derzsy's disease (DD), must be reported to the veterinary administration due to the serious economic and epizootic threat to waterfowl production. Prophylactic treatment for DD includes attenuated live or inactivated vaccines. Moreover, the control of DD includes the monitoring of maternal derived antibody (MDA) levels in the offspring and antibody titers in the parent flock after vaccination. The aim of this study was to develop an ELISA for the detection of goose parvovirus (GPV) antibodies. RESULTS: Two recombinant protein fragments derived from VP3 (viral protein 3) GPV, namely VP3ep6 and VP3ep4-6 with a mass of 20.9 and 32.3 kDa, respectively, were produced using an Escherichia coli expression system. These proteins were purified by one-step nickel-affinity chromatography, which yielded protein preparations with a purity above 95%. These recombinant proteins were useful in the detection of serum anti-GPV antibodies, and this was confirmed by Western blotting. However, recombinant VP3ep4-6 protein showed a greater ability to correctly identify sera from infected geese. In the next stage of the project, a pool of 166 goose sera samples, previously examined by a virus neutralization test (VN), was tested. For further studies, one recombinant protein (VP3ep4-6) was selected for optimization of the test conditions. After optimization, the newly developed ELISA was compared to other serological tests, and demonstrated high sensitivity and specificity. CONCLUSION: In conclusion, the VP3ep4-6 ELISA method described here can be used for the detection of antibodies to GPV in serum.


Assuntos
Anticorpos Antivirais/sangue , Proteínas do Capsídeo/imunologia , Ensaio de Imunoadsorção Enzimática/veterinária , Infecções por Parvoviridae/veterinária , Parvovirinae/imunologia , Doenças das Aves Domésticas/diagnóstico , Animais , Ensaio de Imunoadsorção Enzimática/normas , Infecções por Parvoviridae/sangue , Infecções por Parvoviridae/diagnóstico , Doenças das Aves Domésticas/sangue , Doenças das Aves Domésticas/virologia , Proteínas Recombinantes/imunologia , Sensibilidade e Especificidade
4.
Vet Microbiol ; 235: 136-142, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282371

RESUMO

Infectious Bursal Disease Virus (IBDV) of the ITA genotype (G6) was shown to have peculiar molecular characteristics and, despite a subclinical course, aggressiveness towards lymphoid tissues after experimental infection of specific-pathogen-free (SPF) chickens. The aim of the present study was to evaluate and compare with a Classical IBDV strain, ITA IBDV distribution and persistence in various tissues (bursa of Fabricious, spleen, thymus, bone marrow, caecal tonsils, Harderian gland, kidney, liver and proventriculus), its cloacal shedding and the involvement of gut TLR-3 in duodenum tissues. The 35-day-old SPF chickens were experimentally infected and sampled up to 28 days post infection (dpi) for IBDV detection and TLR-3 quantification by qRT-PCR. The ITA IBDV strain was detected in lymphoid and most non-lymphoid tissues up to the end of the trial, with higher loads compared to the Classical IBDV. Most of those differences were found during the first 2 weeks post-infection. Notably, bone marrow and caecal tonsils presented higher viral loads until 28 dpi, allowing to speculate that these organs may serve as non-bursal lymphoid tissues supporting virus replication. Differences in relative TLR-3 gene expression between ITA IBDV-infected birds and Classical-IBDV infected ones were observed at 4, 14 and 21 dpi, being initially higher in Classical group and later in ITA group. Our results provide new insights into IBDV pathogenesis showing that IBDV of ITA genotype leads to a high and persistent viral load in lymphoid tissues and to a delayed antiviral response.


Assuntos
Infecções por Birnaviridae/veterinária , Vírus da Doença Infecciosa da Bursa/genética , Tecido Linfoide/virologia , Doenças das Aves Domésticas/imunologia , Carga Viral , Animais , Infecções por Birnaviridae/imunologia , Medula Óssea/patologia , Medula Óssea/virologia , Galinhas , Ensaio de Imunoadsorção Enzimática , Genótipo , Vírus da Doença Infecciosa da Bursa/patogenicidade , Tonsila Palatina/virologia , Doenças das Aves Domésticas/virologia , Organismos Livres de Patógenos Específicos , Receptor 3 Toll-Like/genética , Replicação Viral
5.
Vet Microbiol ; 235: 151-163, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282373

RESUMO

This study demonstrates that the Muscovy duck reovirus (MDRV) p10.8 protein is one of many viral non-structural proteins that induces both cell cycle arrest and apoptosis. The p10.8 but not σC is a nuclear targeting protein that shuttles between the nucleus and the cytoplasm. Our results reveal that p10.8-induced apoptosis in cultured cells occurs by the nucleoporin Tpr/p53-dependent and Fas/caspase 8-mediated pathways. Furthermore, a compelling finding from this study is that the p10.8 and σC proteins of MDRV facilitate CDK2 and CDK4 degradation via the ubiquitin-proteasome pathway. We found that depletion of Cdc20 reversed the p10.8- and σC- mediated CDK4 degradation and p10.8-induced apoptosis, suggesting that Cdc20 plays a critical role in modulating p10.8-mediated cell cycle and apoptosis. Furthermore, we found that depletion of chaperonin-containing tailless complex polypeptide 1 (CCT) 2 and CCT5 reduced the level of Cdc20 and reversed the p10.8- and σC-mediated CDK4 degradation and p10.8-induced apoptosis, indicating that molecular chaperone CCT2 and CCT5 are required for stabilization of Ccd20 for mediating both cell cycle arrest and apoptosis. This study provides mechanistic insights into how p10.8 induces both cell cycle arrest and apoptosis.


Assuntos
Proteínas Cdc20/metabolismo , Chaperonina com TCP-1/metabolismo , Orthoreovirus/genética , Doenças das Aves Domésticas/virologia , Infecções por Reoviridae/veterinária , Proteínas não Estruturais Virais/metabolismo , Animais , Apoptose , Caspase 8/genética , Caspase 8/metabolismo , Proteínas Cdc20/genética , Pontos de Checagem do Ciclo Celular , Linhagem Celular , Cercopithecus aethiops , Chaperonina com TCP-1/genética , Patos/virologia , Fibroblastos/virologia , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , RNA Interferente Pequeno , Células Vero , Proteínas não Estruturais Virais/genética
6.
Vet Microbiol ; 235: 164-169, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282374

RESUMO

Marek's disease virus (MDV) is a highly contagious alphaherpesvirus that causes rapid onset of T cell lymphomas in chickens. MDV continues to break through vaccinal immunity due to the emergence of highly virulent field strains. Earlier studies revealed that deletion of the meq gene from MDV results in attenuated vaccines that protect against disease when chickens are infected with highly virulent strains. However, meq-deleted viruses still retain the ability to induce lymphoid organ atrophy, which raises safety concerns. In an earlier study, we found that deletion of lorf9 counteracts this lymphoid organ atrophy. Here, we describe the generation of a double deletion mutant virus lacking virus-encoded meq and lorf9. In vitro studies revealed that during replication, the mutant virus had kinetic characteristics similar to the parental virus; however, in vivo the replication capability was significantly reduced. Results of animal studies revealed no obvious MDV-specific symptoms and lesions. Importantly, the double deletion mutant virus lost the capacity to induce lymphoid organ atrophy, which has been the main obstacle during development of a good vaccine candidate.


Assuntos
Deleção de Genes , Herpesvirus Galináceo 1/genética , Herpesvirus Galináceo 1/patogenicidade , Tecido Linfoide/patologia , Doença de Marek/patologia , Proteínas Oncogênicas Virais/genética , Animais , Atrofia , Galinhas , Tecido Linfoide/virologia , Mutação , Doenças das Aves Domésticas/virologia , Replicação Viral
7.
Arch Virol ; 164(10): 2525-2530, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31286221

RESUMO

In this study, we investigated which structural proteins of pigeon paramyxovirus type 1 (PPMV-1) are responsible for its low pathogenicity in chickens. The results revealed that the pathogenicity of the virus is determined by multiple genes. The NP protein and F protein were found to have the strongest individual effect on virulence, and this effect further enhanced when the two proteins were expressed in combination. Our study highlights the influence of the NP and F proteins on the pathogenicity of PPMV-1 in chickens.


Assuntos
Doença de Newcastle/virologia , Vírus da Doença de Newcastle/genética , Vírus da Doença de Newcastle/patogenicidade , Proteínas do Nucleocapsídeo/genética , Doenças das Aves Domésticas/virologia , Proteínas Virais de Fusão/genética , Fatores de Virulência/genética , Animais , Galinhas , Columbidae , Doença de Newcastle/patologia , Vírus da Doença de Newcastle/isolamento & purificação , Doenças das Aves Domésticas/patologia , Virulência
8.
Onderstepoort J Vet Res ; 86(1): e1-e6, 2019 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-31291734

RESUMO

Between July and September 2017, samples collected from six unvaccinated chickens in Namibia were shown to be positive for infectious bursal disease virus (IBDV) by RT-PCR. Partial sequence and phylogenetic analysis of the VP1 and VP2 genes from six viruses revealed that they all belong to the very virulent pathotype (Genogroup 3) and are genetically very similar to IBDVs identified in neighbouring Zambia. This is the first molecular characterisation of IBDV in Namibia and has implications on the control and management of the disease in the country.


Assuntos
Infecções por Birnaviridae/veterinária , Galinhas , Vírus da Doença Infecciosa da Bursa/isolamento & purificação , Doenças das Aves Domésticas/epidemiologia , Animais , Infecções por Birnaviridae/epidemiologia , Vírus da Doença Infecciosa da Bursa/genética , Namíbia/epidemiologia , Filogenia , Doenças das Aves Domésticas/virologia , Análise de Sequência de DNA/veterinária
9.
BMC Vet Res ; 15(1): 232, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286975

RESUMO

BACKGROUND: Recently, serotype 4 fowl adenovirus (FAdV-4) has spread widely and caused huge economic loss to poultry industry. However, little is known about the molecular pathogenesis of FAdV-4. Fiber protein is thought to be vital for its infection and pathogenesis. RESULTS: Two novel monoclonal antibodies (mAbs) targeting the fiber-1 protein of FAdV-4 were generated, designated as mAb 3B5 and 6H9 respectively. Indirect immunofluorescence assay (IFA) showed that both mAbs only reacted with the FAdV-4 and FAdV-10, not with other serotypes including FAdV-1, FAdV-5, FAdV-6, FAdV-7, FAdV-8 and FAdV-9 tested. Although both mAbs did not recognize the linear epitopes, they could efficiently immunoprecipitate the fiber-1 protein in LMH cells either infected with FAdV-4 or transfected with pcDNA3.1-Fiber-1. Moreover, mAb 3B5 as a capture antibody and HRP-conjugated mAb 6H9 as a detection antibody, a novel sandwich ELISA for efficient detection of FAdV-4 was generated. The limit of detection of the ELISA could reach to 1000 TCID50/ml of FAdV-4 and the ELISA could be efficiently applied to detect FAdV-4 in the clinical samples. CONCLUSION: The two mAbs specific targeting fiber-1 generated here would pave the way for further studying on the role of fiber-1 in the infection and pathogenesis of FAdV-4, and the established mAb based sandwich ELISA would provide an efficient diagnostics tool for detection of FAdV-4/10.


Assuntos
Infecções por Adenoviridae/diagnóstico , Anticorpos Monoclonais/metabolismo , Aviadenovirus/fisiologia , Proteínas do Capsídeo/imunologia , Doenças das Aves Domésticas/diagnóstico , Infecções por Adenoviridae/virologia , Animais , Anticorpos Antivirais/metabolismo , Aviadenovirus/genética , Proteínas do Capsídeo/genética , Linhagem Celular , Galinhas , Ensaio de Imunoadsorção Enzimática , Técnica Indireta de Fluorescência para Anticorpo , Limite de Detecção , Camundongos Endogâmicos BALB C , Doenças das Aves Domésticas/virologia
10.
J Vet Sci ; 20(3): e27, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31161745

RESUMO

In 2016, novel H5N6 highly pathogenic avian influenza virus emerged in Korea. During the outbreak, the virus caused the largest culling, especially in brown chicken lines. We determined the pathogenicity and transmissibility of the virus in 2 white chicken lines of the specific pathogen-free chickens, broilers and brown chicken line of Korean native chicken (KNC). A KNC had a longer virus shedding period and longer mean death time than others. Our study showed that this characteristic in the KNC might have contributed to a farm-to-farm transmission of the brown chicken farms.


Assuntos
Vírus da Influenza A/patogenicidade , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Animais , Cruzamento , Galinhas/virologia , Influenza Aviária/transmissão , Doenças das Aves Domésticas/transmissão , República da Coreia , Virulência
11.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 35(5): 412-418, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31223110

RESUMO

Objective To measure the effect of duck viperin protein on the proliferation of duck Tembusu virus (DTMUV). Methods We analyzed the duck viperin gene using a bioinformatics. Plasmids pGEX-6P-viperin and pEGFP-N1-viperin were constructed and transformed into Rosseta and transfected into BHK-21 cells, respectively. BHK-21 cells transfected with plasmid pEGFP-N1-viperin and empty vector were infected with DTMUV. The content of DTMUV in cell precipitation and supernatant was analyzed by real-time fluorescent quantitative PCR. Finally, the effect of viperin on DTMUV proliferation and the binding proteins captured by EGFP monoclonal antibody were evaluated using mass spectrometry. Results Significant differences were observed between the expression levels of viperin gene in duck compared to other species. Duck viperin was found to inhibit the budding of DTMUV in BHK-21 cells. Further, we identified six proteins that might be involved in the inhibition of the proliferation and budding of DTMUV, possibly indicative of the viperin anti-Tembusu virus pathway in ducks. Conclusion Expression patterns of duck viperin reveal how the budding of duck Tembusu virus is inhibited.


Assuntos
Patos , Flavivirus/fisiologia , Doenças das Aves Domésticas/virologia , Proteínas/metabolismo , Liberação de Vírus , Animais , Anticorpos Monoclonais , Linhagem Celular , Cricetinae , Proteínas/genética , Transfecção
12.
Vet Immunol Immunopathol ; 212: 15-22, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31213247

RESUMO

Marek's disease virus (MDV), an α-herpesvirus targeting avian species, causes fatal Marek's disease (MD) in chickens. The host interferon (IFN) responses play a key role in resisting viral infection. However, host IFN responses following MDV infection in the chicken central immune organs (thymus and bursa of Fabricius), which contain numerous MDV target cells, is poorly understood. In this study, we performed animal experiments in specific pathogen-free chickens infected with two virulent MDV strains (BS/15 and Md5) or without infection as negative controls. Specifically, the type I IFN (IFN-α and IFN-ß) transcriptional and proteomic expression levels at 7, 10, 14, 17, and 21 days post infection (dpi) were detected and analyzed. Our results indicated that the mRNA and protein expression levels of IFN-α and IFN-ß in the thymus and bursa of Fabricius were mainly downregulated in cytolytic infection (such as 10 dpi) and reactivation (such as 17 dpi) stages, but not the latent (such as 14 dpi) stage of MDV infection, which was determined by comprehensively analyzing the MDV viral load and immune organ damage caused by MDV infection. These data suggest that MDV could inhibit the expression of host type I IFNs, which may be involved in the MDV-induced host immunosuppression and contribute to the immune escape of MDV from host immunity. Furthermore, we found that the downregulated expression of the host type I IFNs induced by BS/15 and Md5 infection was significantly different, which we speculated may be related to the diverse virulence and pathogenicity of MDV strains. In conclusion, our study demonstrated that MDV mostly inhibited the expression of type I IFNs in infected hosts, which may be associated to its pathogenesis.


Assuntos
Interferon Tipo I/imunologia , Doença de Marek/imunologia , Doenças das Aves Domésticas/imunologia , Animais , Bolsa de Fabricius/imunologia , Galinhas , Expressão Gênica , Herpesvirus Galináceo 2 , Interferon Tipo I/genética , Interferon-alfa/genética , Interferon-alfa/imunologia , Interferon beta/genética , Interferon beta/imunologia , Doenças das Aves Domésticas/virologia , Proteômica , RNA Mensageiro/genética , Organismos Livres de Patógenos Específicos , Timo/imunologia , Carga Viral , Virulência
13.
BMC Vet Res ; 15(1): 205, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31208467

RESUMO

BACKGROUND: Poultry farming is widely practiced by rural households in Vietnam and the vast majority of domestic birds are kept on small household farms. However, smallholder poultry production is constrained by several issues such as infectious diseases, including avian influenza viruses whose circulation remains a threat to public health. This observational study describes the demographic structure and dynamics of small-scale poultry farms of the Mekong river delta region. METHOD: Fifty three farms were monitored over a 20-month period, with farm sizes, species, age, arrival/departure of poultry, and farm management practices recorded monthly. RESULTS: Median flock population sizes were 16 for chickens (IQR: 10-40), 32 for ducks (IQR: 18-101) and 11 for Muscovy ducks (IQR: 7-18); farm size distributions for the three species were heavily right-skewed. Muscovy ducks were kept for long periods and outdoors, while chickens and ducks were farmed indoors or in pens. Ducks had a markedly higher removal rate (broilers: 0.14/week; layer/breeders: 0.05/week) than chickens and Muscovy ducks (broilers: 0.07/week; layer/breeders: 0.01-0.02/week) and a higher degree of specialization resulting in a substantially shorter life span. The rate of mortality due to disease did not differ much among species, with birds being less likely to die from disease at older ages, but frequency of disease symptoms differed by species. Time series of disease-associated mortality were correlated with population size for Muscovy ducks (Kendall's coefficient τ = 0.49, p-value < 0.01) and with frequency of outdoor grazing for ducks (τ = 0.33, p-value = 0.05). CONCLUSION: The study highlights some challenges to disease control in small-scale multispecies poultry farms. The rate of interspecific contact and overlap between flocks of different ages is high, making small-scale farms a suitable environment for pathogens circulation. Muscovy ducks are farmed outdoors with little investment in biosecurity and few inter-farm movements. Ducks and chickens are more at-risk of introduction of pathogens through movements of birds from one farm to another. Ducks are farmed in large flocks with high turnover and, as a result, are more vulnerable to disease spread and require a higher vaccination coverage to maintain herd immunity.


Assuntos
Criação de Animais Domésticos/métodos , Galinhas , Patos , Doenças das Aves Domésticas/epidemiologia , Fatores Etários , Animais , Fazendas/estatística & dados numéricos , Dinâmica Populacional , Doenças das Aves Domésticas/mortalidade , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/virologia , Vietnã
14.
Vet Microbiol ; 233: 1-4, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31176393

RESUMO

Domestic ducks are considered as the interface between wild aquatic birds and terrestrial poultry and play an important role in the transmission and evolution of avian influenza viruses (AIVs). However, the infectivity of H9N2 AIVs in different domestic duck species has not been systematically evaluated. Here we investigated the infectivity of various genotypes of chicken H9N2 AIVs in Pekin duck (Anas Platyrhynchos), Mallard duck (Anas Platyrhynchos) and Muscovy duck (Cairina Moschata) through intranasal inoculation. We found that Pekin ducks and Mallard ducks were generally resistant to chicken H9N2 virus infection, while Muscovy ducks were relatively susceptible to H9N2 AIVs. All the tested viruses were isolated from oropharynx, trachea and lung tissues of Muscovy ducks. Additionally, genotype 57 (G57) H9N2 AIVs, which was predominant in chickens since 2010, showed increased virus replication in this duck species, indicating an improved interspecies transmission ability of recent H9N2 viruses from chickens to ducks. Our results demonstrated the role of Muscovy ducks in the ecology of H9N2 AIVs. More attentions should be paid to this host during viral surveillances. Additionally, inactivated H9N2 vaccine may be unnecessarily used in Pekin and Mallard ducks.


Assuntos
Patos/virologia , Influenza Aviária/transmissão , Doenças das Aves Domésticas/virologia , Replicação Viral , Animais , Galinhas/virologia , Suscetibilidade a Doenças , Vírus da Influenza A Subtipo H9N2/genética , Vírus da Influenza A Subtipo H9N2/fisiologia , Pulmão/virologia , Orofaringe/virologia , Traqueia/virologia
15.
Vet Microbiol ; 233: 85-92, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31176417

RESUMO

Muscovy duck reovirus (MDRV) causes serious immunodeficiency in the intestinal mucosa, although the underlying histopathological mechanisms remain unclear. Thus, we investigated the impact of MDRV infection on intestinal morphology using hematoxylin and eosin staining. Immune-related cells were also quantified by staining with hematoxylin and eosin, toluidine blue, and periodic acid-Schiff stain, or by immunohistochemistry and cytochemistry for lectin. Similarly, CD4+ and CD8+ cells were quantified by flow cytometry, and the expression of several immune-related molecules was quantified by radioimmunoassay. We found that MDRV clearly damaged the intestinal mucosa, based on tissue morphology, villus length, villus width, intestinal thickness, villus height/crypt depth ratio, and villus surface area. MDRV also altered the density or distribution of lymphocytes, mastocytes, and goblet cells in the small intestinal mucosa, as well as microfold cells in Peyer's patches. In addition, MDRV markedly depleted CD4+ cells from the intestinal mucosa and lowered the CD4+:CD8+ ratio in peripheral blood. Moreover, MDRV diminished the levels of secretory IgA and mucosal addressin cell adhesion molecule-1 (p < 0.01), but elevated those of histamine and nitric oxide (p < 0.01 or p < 0.05). Finally, MDRV significantly suppressed IL-1ß, IL-4, IL-5, and IL-8 levels (p < 0.01 or p < 0.05) mid-infection. Collectively, our data suggest that MDRV severely damages the structure and function of the intestinal mucosa by modulating immune cells and immune-related factors, thus leading to local immunodeficiency. Our findings lay the foundation for further research on the pathogenesis of MDRV.


Assuntos
Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Intestino Delgado/virologia , Orthoreovirus Aviário/imunologia , Infecções por Reoviridae/imunologia , Fatores Etários , Animais , Contagem de Linfócito CD4 , Citocinas/imunologia , Patos/virologia , Duodeno , Fibroblastos/virologia , Histamina/análise , Imunoglobulina A Secretora/análise , Intestino Delgado/imunologia , Óxido Nítrico/análise , Orthoreovirus Aviário/patogenicidade , Doenças das Aves Domésticas/virologia , Infecções por Reoviridae/patologia , Carga Viral
16.
BMC Infect Dis ; 19(1): 458, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31117981

RESUMO

BACKGROUND: Since 2008, avian influenza surveillance in poultry-related environments has been conducted annually in China. Samples have been collected from environments including live poultry markets, wild bird habitats, slaughterhouses, and poultry farms. Multiple subtypes of avian influenza virus have been identified based on environmental surveillance, and an H1N8 virus was isolated from the drinking water of a live poultry market. METHODS: Virus isolation was performed by inoculating influenza A-positive specimens into embryonated chicken eggs. Next-generation sequencing was used for whole-genome sequencing. A solid-phase binding assay was performed to test the virus receptor binding specificity. Trypsin dependence plaque formation assays and intravenous pathogenicity index tests were used to evaluate virus pathogenicity in vitro and in vivo, respectively. Different cell lines were chosen for comparison of virus replication capacity. RESULTS: According to the phylogenetic trees, the whole gene segments of the virus named A/Environment/Fujian/85144/2014(H1N8) were of Eurasian lineage. The HA, NA, PB1, and M genes showed the highest homology with those of H1N8 or H1N2 subtype viruses isolated from local domestic ducks, while the PB2, PA, NP and NS genes showed high similarity with the genes of H7N9 viruses detected in 2017 and 2018 in the same province. This virus presented an avian receptor binding preference. The plaque formation assay showed that it was a trypsin-dependent virus. The intravenous pathogenicity index (IVPI) in chickens was 0.02. The growth kinetics of the A/Environment/Fujian/85144/2014(H1N8) virus in different cell lines were similar to those of a human-origin virus, A/Brisbane/59/2007(H1N1), but lower than those of the control avian-origin and swine-origin viruses. CONCLUSIONS: The H1N8 virus was identified in avian influenza-related environments in China for the first time and may have served as a gene carrier involved in the evolution of the H7N9 virus in poultry. This work further emphasizes the importance of avian influenza virus surveillance, especially in live poultry markets (LPMs). Active surveillance of avian influenza in LPMs is a major pillar supporting avian influenza control and response.


Assuntos
Vírus da Influenza A/genética , Vírus da Influenza A/patogenicidade , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Animais , Linhagem Celular , Embrião de Galinha , Galinhas , China , Patos , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/isolamento & purificação , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/epidemiologia , Filogenia , Aves Domésticas/virologia , Tripsina/genética , Tripsina/metabolismo , Sequenciamento Completo do Genoma
17.
Int J Mol Sci ; 20(9)2019 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-31064083

RESUMO

Avian infectious bronchitis virus (IBV) causes considerable economic losses in the poultry industry worldwide, including Taiwan. IBV is among the most important pathogens in chickens, and it spreads rapidly among flocks. In addition to dozens of known serotypes, new viral variants have emerged due to the viral evolution and antigenic variation in IBVs. Therefore, the development of a sensitive, specific, and easily performed assay is crucial for the rapid detection and surveillance of IBV infections. A rapid and simple immunochromatographic strip (ICS) was developed in this study by employing monoclonal antibodies against spike and nucleocapsid proteins of IBV as the tracer and the capture antibody. The ICS showed high specificity in detecting IBV antigens, including several IBV genotypes and novel variants, as opposed to three other common avian respiratory viruses. The detection limit of the strip reached 104.4 50% embryo-infective dose. Moreover, in the experimental chicken model, the strip test demonstrated consistency in detecting IBV with RT-PCR gene detection. Taken together, this antigen detection strip has the potential to serve as an on-farm rapid test for IBV; therefore, it may facilitate surveillance and control of the disease.


Assuntos
Infecções por Coronavirus/diagnóstico , Vírus da Bronquite Infecciosa/imunologia , Técnicas de Diagnóstico Molecular/veterinária , Doenças das Aves Domésticas/diagnóstico , Animais , Antígenos Virais/imunologia , Galinhas , Infecções por Coronavirus/veterinária , Infecções por Coronavirus/virologia , Feminino , Imunoensaio/métodos , Imunoensaio/normas , Imunoensaio/veterinária , Camundongos , Camundongos Endogâmicos BALB C , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/normas , Doenças das Aves Domésticas/virologia , Fitas Reagentes/normas
18.
Microb Pathog ; 132: 362-368, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31054366

RESUMO

Duck Tembusu virus (DTMUV) is a newly emerging pathogenic flavivirus that has caused massive economic losses to the duck industry in China. The cellular factors required for DTMUV replication have been poorly studied. The ubiquitin-proteasome system (UPS), the major intracellular proteolytic pathway, mediates diverse cellular processes, including endocytosis and signal transduction, which may be involved in the entry of virus. In the present study, we explored the interplay between DTMUV replication and the UPS in BHK-21 cells and found that treatment with proteasome inhibitor (MG132 and lactacystin) significantly decreased the DTMUV progency at the early infection stage. We further revealed that inhibition of the UPS mainly occurs on the level of viral protein expression and RNA transcription. In addition, using specific siRNAs targeting ubiquitin reduces the production of viral progeny. In the presence of MG132 the staining for the envelope protein of DTMUV was dramatically reduced in comparison with the untreated control cells. Overall, our observations reveal an important role of the UPS in multiple steps of the DTMUV infection cycle and identify the UPS as a potential drug target to modulate the impact of DTMUV infection.


Assuntos
Flavivirus/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina/metabolismo , Replicação Viral/fisiologia , Acetilcisteína/análogos & derivados , Acetilcisteína/antagonistas & inibidores , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Patos , Flavivirus/efeitos dos fármacos , Flavivirus/patogenicidade , Técnicas de Silenciamento de Genes , Leupeptinas/antagonistas & inibidores , Doenças das Aves Domésticas/virologia , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , RNA Interferente Pequeno , Transfecção , Ubiquitina/efeitos dos fármacos , Ubiquitina/genética , Proteínas do Envelope Viral , Internalização do Vírus
19.
BMC Vet Res ; 15(1): 153, 2019 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-31101110

RESUMO

BACKGROUND: Duck viral hepatitis (DVH) is a highly contagious viral disease affecting ducks. It can be caused by five agents, including duck hepatitis A virus genotypes 1 (DHAV-1), 2 (DHAV-2), and 3 (DHAV-3), as well as duck hepatitis virus 2 and duck hepatitis virus 3. Since 2007, DHAV-3 has been known to be the most prevalent in East and South Asia. So far, the information regarding the propagation of DHAV-3 in cultured cells is limited. In this study, we describe the comparative studies on the growth properties of DHAV-3 in primary duck embryo fibroblast (DEF) cells using two different strains: a virulent strain C-GY and an attenuated strain YDF120. The effect of fetal calf serum (FCS) and chick serum (CS) on DHAV-3 replication and the mechanism of the inhibitory effect conferred by FCS were also investigated. RESULTS: Following serial passages, both C-GY and YDF120 failed to produce cytopathic effect and plaques. The combined quantitative real-time PCR and indirect immunofluorescence staining methods showed that the two viruses could be propagated productively in DEF cells. Investigation of the viral growth kinetics revealed that the two viruses replicated in DEF cells with similar efficiencies, while the viral load of the virulent C-GY strain peaked more rapidly when compared with the attenuated YDF120 strain. Neutralization assay and time-of-drug-addition study indicated that FCS displayed inhibitory effect on DHAV-3 replication. Analysis on the mechanism of action of FCS against DHAV-3 demonstrated that the inhibitory effect was reflected at three steps of the DHAV-3 life cycle including adsorption, replication, and release. CONCLUSIONS: Both virulent and attenuated DAHV-3 strains can establish noncytocidal, productive infections in DEF cells. The virulent strain replicates more rapidly than the attenuated strain in early infection period. FCS has an inhibitory effect on DHAV-3 replication, which may be attributed to action of a non-specific inhibitory factor present in FCS directly on the virus. These findings may provide new insights into the development of potential antiviral agents.


Assuntos
Sangue Fetal , Vírus da Hepatite do Pato/crescimento & desenvolvimento , Animais , Bovinos , Células Cultivadas , Galinhas/sangue , Patos , Embrião não Mamífero/virologia , Fibroblastos/virologia , Vírus da Hepatite do Pato/efeitos dos fármacos , Hepatite Viral Animal/virologia , Infecções por Picornaviridae/veterinária , Infecções por Picornaviridae/virologia , Doenças das Aves Domésticas/virologia
20.
BMC Vet Res ; 15(1): 173, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31126305

RESUMO

BACKGROUND: Avian reovirus (ARV) is an important pathogen that can cause serious disease in poultry. Though several in vitro studies revealed some molecular mechanisms that are responsible for ARV-induced autophagy, it is still largely unknown how ARV manipulates autophagy to promote its own propagation. RESULTS: In this study, we demonstrated that ARV infection triggered autophagy in chicken tissues, evident from the enhancement of LC3-I/-II conversion and the appearance of abundant autophagosomes. Moreover, viral replication and the expression of IL-1ß were coupled with the process of ARV-induced autophagy in the early stage of infection. Furthermore, regulation of autophagy affected the accumulation of LC3-II, the production of ARV and the expression of IL-1ß. CONCLUSIONS: Altogether, our data suggest that ARV induces autophagy, which benefits its replication and dissemination in chicken tissues at the early infection stage.


Assuntos
Autofagia/fisiologia , Orthoreovirus Aviário/fisiologia , Doenças das Aves Domésticas/virologia , Replicação Viral/fisiologia , Animais , Galinhas , Interleucina-1beta/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Infecções por Reoviridae/virologia
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