Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 634
Filtrar
1.
Poult Sci ; 100(10): 101406, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34428643

RESUMO

FAdV-4 is the major strain of adenovirus that responsible for hydro-pericardial syndrome (HPS) in poultry. In this study, the virus's specific gene fragments were isolated from clinically suspected cases and amplified by PCR. Finally, after a viral infection to investigate the immune response of the host, the gene expression of MHC (major histo-compatible) molecules (MHCIα, MHCIIß), Ii (Invariant Chain) gene, inflammatory cytokines (IFN-ß, IFN-γ, and IL-1ß), and transcription factors (MDA5, STING, IRF7, and NF-kB) were detected by real-time PCR (fluorescence technology). The results of sequence comparison showed that the clinically isolated virus was 100% homologous to a virulent strain of avian adenovirus group C serotype 4 (FAdV-4), which were named AH-FAdV-4. The TCID50 and pathogenicity of the virus were determined that was 106.52/0.1 mL with a mortality rate of 100% in chickens and 0% in ducks. Furthermore, results showed that the expression level of MHCIα, MHCIIß, and Ii genes in chicken embryo kidney cells significantly (P < 0.01) upregulated (increased) after infection, which was 43, 5.2, and 2.5 times higher than the control group. With the addition of PDTC, an inhibitor of NF-kB, then the expression level of MHCIα, MHCIIß, and Ii was decreased significantly (P < 0.01) than the control group. The transcription levels of these genes were decreased 0.64, 0.27, and 0.26 respectively. Simultaneously, the expression levels of IFN-ß, IFN-γ, and IL-1ß were also significantly (P < 0.01) up-regulated (increased) 7.8, 22.7, and 5 times higher than the control group. It was found that up-regulation of STING and NF-κB pathways are directly involved in the regulation of inflammatory cytokines (IFN-ß, IFN-γ, and IL-1ß), MHC molecules (MHCIα, MHCIIß), and Ii gene. The results also showed that the gene regulation pathways consecutively increased the expression levels of MDA5, STING, IRF7, and NF-kB. It is conducted that the expression levels of cytokines, MHC molecules, and li gene were increased by STING and NF-kB pathways.


Assuntos
Infecções por Adenoviridae , Aviadenovirus , Doenças das Aves Domésticas , Adenoviridae , Infecções por Adenoviridae/veterinária , Animais , Aviadenovirus/genética , Embrião de Galinha , Galinhas/genética , Interferons , Doenças das Aves Domésticas/genética , Sorogrupo
2.
Avian Dis ; 65(1): 52-58, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-34339122

RESUMO

A flock of captive bobwhite quail (Colinus virginianus) experienced loose droppings, depression, and increased mortality starting at 3 wk of age. Necropsy of the affected birds revealed intestines dilated with frothy and tan fluid. Irregular dark brown fissures within the koilin layer of the gizzard were found in 20%-30% of the birds. Histologically, gizzards showed multifocal koilin degeneration or fragmentation, degeneration and necrosis of the subjacent epithelial cells, and infiltration of macrophages, lymphocytes, and heterophils. Necrotic epithelial cells occasionally contained large, smudgy, basophilic intranuclear inclusion bodies with marginated nuclear chromatin. Adenoviral paracrystalline arrays composed of icosahedral virions (60-70 nm diameter) were seen on transmission electron microscopy in the nuclei of epithelial cells in the gizzard mucosa. Adenovirus was isolated from gizzard, liver, intestine, and trachea by inoculation of specific-pathogen-free embryonated chicken eggs. Homogenates of the gizzard, liver, and intestine were positive for the adenovirus hexon gene by PCR. Sequencing of PCR amplicons confirmed the virus as fowl aviadenovirus A. The study isolates showed more than 99% and 97% nucleotide identity with quail bronchitis virus and with aviadenoviruses from gizzard erosion and ulceration (GEU) in broilers, respectively. The viral isolates showed six substitutions (G1T, C174A, A229G, C513A, T579A, and G621C) of which two were nonsynonymous (G1T and A229G), resulting in a change in the translated amino acid as A1S and S77G, respectively. These results indicate that adenoviruses of the same type or species can cause different clinical presentations in quails, e.g., bronchitis or GEU.


Assuntos
Infecções por Adenoviridae/veterinária , Aviadenovirus/fisiologia , Colinus , Doenças das Aves Domésticas/epidemiologia , Úlcera Gástrica/veterinária , Infecções por Adenoviridae/epidemiologia , Infecções por Adenoviridae/patologia , Infecções por Adenoviridae/virologia , Animais , Moela das Aves/patologia , Minnesota/epidemiologia , Úlcera Péptica , Doenças das Aves Domésticas/patologia , Doenças das Aves Domésticas/virologia , Úlcera Gástrica/epidemiologia , Úlcera Gástrica/patologia , Úlcera Gástrica/virologia
3.
J Vet Sci ; 22(4): e42, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34313038

RESUMO

BACKGROUND: Inclusion body hepatitis (IBH) is an economically important viral disease primarily affecting broiler and breeder chickens. All 12 serotypes of fowl adenovirus (FAdV) can cause IBH. OBJECTIVES: To characterize FAdV isolates based on phylogenetic analysis, and to study the pathogenicity of FAdV-8b in specific-pathogen-free (SPF) chickens following virus inoculation via oral and intramuscular (IM) routes. METHODS: Suspected organ samples were subjected to virus isolation and polymerase chain reaction (PCR) for FAdV detection. Hexon gene sequencing and phylogenetic analysis were performed on FAdV-positive samples for serotype identification. One FAdV-8b isolate, UPM/FAdV/420/2017, was selected for fiber gene characterization and pathogenicity study and was inoculated in SPF chickens via oral and IM routes. RESULTS: The hexon gene phylogenetic analysis revealed that all isolates belonged to FAdV-8b. The fiber gene-based phylogenetic analysis of isolate UPM/FAdV/420/2017 supported the grouping of that isolate into FAdV species E. Pathogenicity study revealed that, chickens infected with UPM/FAdV/420/2017 via the IM route had higher clinical score values, higher percent mortality, higher degree of the liver lesions, higher antibody response (p < 0.05), and higher virus shedding amounts (p < 0.05) than those infected via the oral route. The highest virus copy numbers were detected in liver and gizzard. CONCLUSIONS: FAdV-8b is the dominant FAdV serotype in Malaysia, and pathogenicity study of the FAdV-8b isolate UPM/FAdV/420/2017 indicated its ability to induce IBH in young SPF chickens when infected via oral or IM routes.


Assuntos
Infecções por Adenoviridae/veterinária , Aviadenovirus/classificação , Galinhas , Doenças das Aves Domésticas/virologia , Infecções por Adenoviridae/epidemiologia , Infecções por Adenoviridae/virologia , Sequência de Aminoácidos , Animais , Aviadenovirus/genética , Malásia/epidemiologia , Filogenia , Doenças das Aves Domésticas/epidemiologia , Sorotipagem , Organismos Livres de Patógenos Específicos , Proteínas Virais/química , Proteínas Virais/metabolismo
4.
Trop Anim Health Prod ; 53(4): 412, 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34308515

RESUMO

Recently, inclusion body hepatitis (IBH) outbreaks have been increasingly reported in different regions of India, particularly in broiler flocks. The present study was undertaken to characterize fowl adenovirus associated with IBH in chicken and assessment of its pathogenicity. Liver samples were collected from fowl adenovirus (FAdV) suspected 100 commercial broiler and six broiler breeder flocks from eleven different States of India from 2016 to 2019. All the samples were subjected to 897-bp FAdV hexon gene-specific PCR for confirmation and primary chicken liver cells were used to isolate the field FAdVs. Sequencing and phylogenetic analysis of 897-bp FAdV hexon gene revealed that all the isolates have showed close evolutionary relationship with fowl adenovirus serotype 11 of species D. For pathogenicity assessment, 0.5 ml of 106.5 TCID50/ml of field FAdV serotype 11 isolate was orally inoculated in 1-day-old SPF chicks and observed for 21 days. This experimental study revealed that there was no mortality in infected chicks and showed clinical signs of dullness, depression and diarrhoea between third and fifth day of oral inoculation. The FAdV was reisolated and confirmed by PCR from experimentally infected chicken. Based on this study, among all serotypes, FAdV serotype 11 is involved in pathogenesis of inclusion body hepatitis in broiler-type chickens in India.


Assuntos
Infecções por Adenoviridae , Aviadenovirus , Hepatite , Doenças das Aves Domésticas , Infecções por Adenoviridae/epidemiologia , Infecções por Adenoviridae/veterinária , Animais , Aviadenovirus/genética , Galinhas , Corpos de Inclusão , Índia/epidemiologia , Tipagem Molecular/veterinária , Filogenia , Doenças das Aves Domésticas/epidemiologia , Virulência
5.
J Virol ; 95(17): e0060321, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34133902

RESUMO

Since 2015, severe hydropericardium-hepatitis syndrome (HHS) associated with a novel fowl adenovirus 4 (FAdV-4) has emerged in China, representing a new challenge for the poultry industry. Although various highly pathogenic FAdV-4 strains have been isolated, the virulence factor and the pathogenesis of novel FAdV-4 are unclear. In our previous studies, we reported that a large genomic deletion (1,966 bp) is not related to increased virulence. Here, two recombinant chimeric viruses, rHN20 strain and rFB2 strain, were generated from a highly pathogenic FAdV-4 strain by replacing the hexon or fiber-2 gene of a nonpathogenic FAdV-4, respectively. Both chimeric strains showed similar titers to the wild-type strain in vitro. Notably, rFB2 and the wild-type strain induced 100% mortality, while no mortality or clinical signs appeared in chickens inoculated with rHN20, indicating that hexon, but not fiber-2, determines the novel FAdV-4 virulence. Furthermore, an R188I mutation in the hexon protein identified residue 188 as the key amino acid for the reduced pathogenicity. The rR188I mutant strain was significantly neutralized by chicken serum in vitro and in vivo, whereas the wild-type strain was able to replicate efficiently. Finally, the immunogenicity of the rescued rR188I was investigated. Nonpathogenic rR188I provided full protection against lethal FAdV-4 challenge. Collectively, these findings provide an in-depth understanding of the molecular basis of novel FAdV-4 pathogenicity and present rR188I as a potential live attenuated vaccine candidate or a novel vaccine vector for HHS vaccines. IMPORTANCE HHS associated with a novel FAdV-4 infection in chickens has caused huge economic losses to the poultry industry in China since 2015. The molecular basis for the increased virulence remains largely unknown. Here, we demonstrate that the hexon gene is vital for FAdV-4 pathogenicity. Furthermore, we show that the amino acid residue at position 188 of the hexon protein is responsible for pathogenicity. Importantly, the rR188I mutant strain was neutralized by chicken serum in vitro and in vivo, whereas the wild-type strain was not. Further, the rR188I mutant strain provided complete protection against FAdV-4 challenge. Our results provide a molecular basis of the increased virulence of novel FAdV-4. We propose that the rR188I mutant is a potential live attenuated vaccine against HHS and a new vaccine vector for HHS-combined vaccines.


Assuntos
Infecções por Adenoviridae/veterinária , Aviadenovirus/patogenicidade , Proteínas do Capsídeo/metabolismo , Galinhas/virologia , Mutação , Doenças das Aves Domésticas/virologia , Proteínas Virais/metabolismo , Infecções por Adenoviridae/virologia , Substituição de Aminoácidos , Animais , Aviadenovirus/classificação , Aviadenovirus/genética , Aviadenovirus/isolamento & purificação , Proteínas do Capsídeo/genética , Proteínas Virais/genética , Virulência
6.
Poult Sci ; 100(8): 101238, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34157559

RESUMO

Hypervirulent fowl adenovirus serotype 4 (hvFAdV-4) has emerged as a major pathogen of hepatitis-hydropericardium syndrome (HHS) with increased mortality in chickens, resulting in economic losses to the Chinese poultry industry since June 2015. Here, we isolated a hypervirulent FAdV-4 (hvFAdV-4) strain (designated GD616) from 25-day-old meat-type chickens with severe HHS in Guangdong Province China in June 2017. The whole genome of the strain GD616 shares high homology with those in the recently-reported hvFAdV-4 isolates in China, with natural deletions of ORF19 and ORF27. A comparative analysis of Hexon and Fiber-2 proteins revealed that 2 unique amino acid residues at positions 378 and 453 of the Fiber-2 protein might be associated with virulence due to their occurrences in all the hvFAdV-4 isolates only. To systemically evaluate the effect of age on the susceptibility of chickens to hvFAdV-4, we used this hvFAdV-4 strain to intramuscularly inoculate 7- to 180-day-old specific-pathogen-free chickens for the evaluation of pathogenicity. These results showed that the pathogenicity of the hvFAdV-4 strain GD616 to chickens exhibited age-relatedness, with younger than 59-day-old chickens showing 100% morbidity and mortality, while 180-day-old chickens still exhibited a hydropericardium syndrome-like clinicopathology with 60% morbidity and 20% mortality. These findings enrich the current available knowledge regarding the pathogenicity of the hypervirulent FAdV-4 virus in chickens with a wide range of ages, which assists with the selection of suitable-aged chickens for the evaluation of hvFAdV-4 vaccines.


Assuntos
Infecções por Adenoviridae , Aviadenovirus , Doenças das Aves Domésticas , Adenoviridae , Infecções por Adenoviridae/veterinária , Animais , Aviadenovirus/genética , Galinhas , China , Filogenia , Sorogrupo , Virulência
7.
J Vet Diagn Invest ; 33(4): 806-809, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34085872

RESUMO

Fowl aviadenovirus (FAdV) species D and E are associated with inclusion body hepatitis (IBH); species C, serotype 4 (hereafter, FAdV4) is associated with hepatitis-hydropericardium syndrome (HHS) in young chickens. Outbreaks of HHS have led to significant losses in the poultry industry in several countries, predominantly in China. In April 2020, FAdV4 was detected in a remote backyard flock in California. In a mixed flock of chickens of various breeds and ages (6 mo to 2 y old), 7 of 30 were found dead within a week without premonitory signs. One additional bird died after the flock was relocated to fresh pasture, bringing the total mortality to 8 of 30 (27%). Postmortem examination of 3 birds revealed good body condition scores and active laying. One chicken had subtle hemorrhages throughout the liver, and the other 2 had diffusely dark mahogany livers. On histopathology, 2 chickens had hepatic necrosis with hepatocytes containing large, mostly basophilic, intranuclear inclusion bodies, identified by electron microscopy as 82.2-nm diameter adenoviral particles. Virus isolation and genomic sequencing performed on a liver sample revealed strains with 99.9% homology to FAdV4 isolates reported from China. To our knowledge, FAdV4 has not been reported in the United States to date. Furthermore, the chickens affected here were all adults and exhibited a variation of serotype 4 disease in which IBH was present but not hydropericardium.


Assuntos
Infecções por Adenoviridae/veterinária , Aviadenovirus/isolamento & purificação , Galinhas , Surtos de Doenças/veterinária , Doenças das Aves Domésticas/epidemiologia , Infecções por Adenoviridae/diagnóstico , Infecções por Adenoviridae/epidemiologia , Infecções por Adenoviridae/virologia , Animais , Aviadenovirus/classificação , California/epidemiologia , Filogenia , Doenças das Aves Domésticas/diagnóstico , Doenças das Aves Domésticas/virologia , Sorogrupo
8.
J Vet Diagn Invest ; 33(4): 762-766, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33856244

RESUMO

Fowl adenovirus serotype 4 (FAdV4), the causative agent of hepatitis-hydropericardium syndrome (HPS), has caused major economic losses to the poultry industry worldwide. Although inactivated vaccines have been deployed widely against FAdV4, a DIVA (differentiating infected from vaccinated animals) test specific for FAdV4 has not been available. We synthesized an immunogenic peptide, corresponding to regions 66-88 aa of the 22K nonstructural protein of FAdV4, and used the peptide as coating antigen to develop an indirect ELISA for a DIVA test specific to FAdV4. Specificity analysis showed that the ELISA only reacted with sera against FAdV4, and not with sera against other pathogens tested. Moreover, the ELISA could effectively differentiate FAdV4-infected chickens from vaccinated chickens. In a test of sera from experimentally infected chickens, the ELISA had 95% and 85% concordance with an indirect immunofluorescence assay (indirect IFA) and a commercial ELISA, respectively, and the concordance was 80.5% between the ELISA and the indirect IFA in detecting clinical infection samples. Our peptide-based ELISA provides an efficient DIVA test for FAdV4 in clinical samples.


Assuntos
Infecções por Adenoviridae/veterinária , Aviadenovirus/isolamento & purificação , Galinhas , Ensaio de Imunoadsorção Enzimática/veterinária , Doenças das Aves Domésticas/diagnóstico , Vacinação/veterinária , Infecções por Adenoviridae/diagnóstico , Infecções por Adenoviridae/virologia , Animais , Anticorpos Antivirais/sangue , Ensaio de Imunoadsorção Enzimática/instrumentação , Ensaio de Imunoadsorção Enzimática/métodos , Peptídeos/química , Doenças das Aves Domésticas/virologia , Sorogrupo
9.
Vet Res ; 52(1): 61, 2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33926543

RESUMO

Infectious bursal disease virus (IBDV) and fowl adenovirus serotype 4 (FAdV-4) cause infectious bursal disease (IBD) and hydropericardium-hepatitis syndrome, respectively. Recently, studies have reported co-infections of poultry with IBDV and FAdV-4, which is an important problem in the poultry industry. Here, the variant IBDV strain ZD-2018-1 and FAdV-4 isolate HB1501 were used to assess the pathogenicity of co-infection in 1-day-old specific pathogen-free (SPF) chickens. Compared with chickens infected with only FAdV-4, those coinfected with IBDV and FAdV-4 showed enhanced clinical symptoms, higher mortality, more severe tissue lesions, and higher biochemical index levels. Furthermore, the expression of interleukin (IL)-6, IL-1ß, and interferon-γ mRNAs in the IBDV-FAdV-4 coinfected chickens was delayed, and the antibody response levels were significantly lower in those birds compared with the FAdV-4-infected chickens. These results indicate that co-infection with variant IBDV ZD-2018-1 and FAdV-4 HB1501 could significantly promote the pathogenicity of FAdV-4 and reduce the immune response in chickens. This study provides the foundation for further investigation of the interaction mechanism in IBDV and FAdV-4 co-infection.


Assuntos
Infecções por Birnaviridae/veterinária , Galinhas , Coinfecção/veterinária , Imunidade Inata , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/mortalidade , Infecções por Adenoviridae/imunologia , Infecções por Adenoviridae/mortalidade , Infecções por Adenoviridae/veterinária , Animais , Aviadenovirus/fisiologia , Infecções por Birnaviridae/imunologia , Infecções por Birnaviridae/mortalidade , Coinfecção/imunologia , Coinfecção/mortalidade , Vírus da Doença Infecciosa da Bursa/fisiologia , Organismos Livres de Patógenos Específicos
10.
Vet Microbiol ; 255: 109026, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33743407

RESUMO

Fowl adenovirus serotype 4 (FAdV-4) is recognized as an economically important pathogen for the poultry industry worldwide. FAdV-4 infection causes a metabolic disturbance of hepatocytes, leading to hydropericardium-hepatitis syndrome (HHS) in poultry. However, the metabolic response of hepatocytes to FAdV-4 infection remains poorly investigated. Here, a tandem mass tag (TMT)-based approach was first used to quantitatively identify differentially expressed proteins (DEPs) in leghorn male hepatoma (LMH) cells infected with the virulent FAdV-4 strain GY. We identified 666 DEPs associated with many biological processes and pathways, according to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses. Functional enrichment analysis revealed that three pathways, including metabolism-related signaling pathways, apoptosis, and autophagy responses, were enriched during FAdV-4 infection. Moreover, excessive induction of metabolism-related signaling pathways by FAdV-4 infection might be associated with HHS induced by the virus. Meanwhile, among the proteins in these pathways, RRM2, SAE1, AEN, and RAD50 were verified through western blotting to be markedly altered in FAdV-4-infected LMH cells. Notably, overexpression of SAE1 inhibited the replication of FAdV-4 in vitro, whereas silencing of SAE1 expression promoted the replication of the virus. Collectively, our findings show for the first time that SAE1 is a host cellular protein that plays roles in regulating the life cycle of FAdV-4.


Assuntos
Aviadenovirus/fisiologia , Hepatócitos/metabolismo , Proteômica/métodos , Animais , Linhagem Celular Tumoral , Galinhas , Inativação Gênica , Hepatócitos/virologia , Doenças das Aves Domésticas/virologia , Transdução de Sinais , Espectrometria de Massas em Tandem , Replicação Viral/fisiologia
11.
Poult Sci ; 100(5): 101052, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33773159

RESUMO

Fowl adenoviruses (FAdV), detected during routine diagnostic investigations from 38 countries (5 continents) over a decade, were partially sequenced and grouped by phylogenetic analysis. The partial polymerase gene nucleotide sequences of the 365 fowl adenovirus isolates resulted in the following species distribution: 11% FAdV-A; 3% FAdV-B; 2% FAdV-C; 34% FAdV-D; and 50% FAdV-E. Noticeably, only 79 of the detected strains could be associated with adenovirus-specific pathologic conditions: 62 (79%) with inclusion body hepatitis; 9 (11%) with gizzard erosion; and 8 (10%) with hepatitis hydropericardium syndrome. The remainder of the FAdV strains was detected as concomitant infection from other disease conditions almost exclusively in boilers of 27 to 42 d of age: the majority of them was FAdV-E followed by FAdV-D, and to a lesser extent of FAdV-A, B, and C, the latter ones have not been associated with any of the established adenovirus-caused syndromes in our collection. The highest ratio of coinfections was observed for FAdV-B (62%), while it was about 30% for the rest of the FAdV species. The most frequent coinfection, in connection with all FAdV species, was with the avian infectious bronchitis virus. The presented database will serve as the basis for comparative whole genome and cross-neutralization analysis of selected FAdV isolates.


Assuntos
Infecções por Adenoviridae , Aviadenovirus , Doenças das Aves Domésticas , Adenoviridae , Infecções por Adenoviridae/epidemiologia , Infecções por Adenoviridae/veterinária , Animais , Aviadenovirus/genética , Galinhas , Filogenia , Doenças das Aves Domésticas/epidemiologia
12.
J Gen Virol ; 102(3)2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33625352

RESUMO

Fibre is the viral protein that mediates the attachment and infection of adenovirus to the host cell. Fowl adenovirus 4 (FAdV-4) possesses two different fibre trimers on each penton capsomere, and roles of the separate fibres remain elusive. Here, we attempted to investigate the function of FAdV-4 fibres by using reverse genetics approaches. Adenoviral plasmids carrying fiber1 or fiber2 mutant genes were constructed and used to transfect chicken LMH cells. Fiber1-mutated recombinant virus could not be rescued. Such defective phenotype was complemented when a fiber1-bearing helper plasmid was included for co-transfection. The infection of fiber-intact FAdV-4 (FAdV4-GFP) to LMH cells could be blocked with purified fiber1 knob protein in a dose-dependent manner, while purifed fiber2 knob had no such function. On the contrary, fiber2-mutated FAdV-4, FAdV4XF2-GFP, was successfully rescued. The results of one-step growth curves showed that proliferative capacity of FAdV4XF2-GFP was 10 times lower than that of the control FAdV4-GFP. FAdV4XF2-GFP also caused fewer deaths of infected chicken embryos than FAdV4-GFP did, which resulted from poorer virus replication in vivo. These data illustrated that fiber1 mediated virus adsorption and was essential for FAdV-4, while fiber2 was dispensable although it significantly contributed to the virulence.


Assuntos
Infecções por Adenoviridae/veterinária , Aviadenovirus/classificação , Aviadenovirus/genética , Doenças das Aves Domésticas/virologia , Genética Reversa , Animais , Embrião de Galinha , Galinhas/virologia , Plasmídeos/genética , Regiões Promotoras Genéticas , Recombinação Genética
13.
Vet Res ; 52(1): 35, 2021 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-33640033

RESUMO

Recently, the outbreaks of hydropericardium-hepatitis syndrome (HHS) caused by the highly pathogenic fowl adenovirus serotype 4 (FAdV-4) have resulted in huge economic losses to the poultry industry globally. Although several inactivated or subunit vaccines have been developed against FAdV-4, live-attenuated vaccines for FAdV-4 are rarely reported. In this study, a recombinant virus FA4-EGFP expressing EGFP-Fiber-2 fusion protein was generated by the CRISPR/Cas9 technique. Although FA4-EGFP shows slightly lower replication ability than the wild type (WT) FAdV-4, FA4-EGFP was significantly attenuated in vivo compared with the WT FAdV-4. Chickens infected with FA4-EGFP did not show any clinical signs, and all survived to 14 day post-infection (dpi), whereas those infected with FAdV-4 showed severe clinical signs with HHS and all died at 4 dpi. Besides, the inoculation of FA4-EGFP in chickens provided efficient protection against lethal challenge with FAdV-4. Compared with an inactivated vaccine, FA4-EGFP induced neutralizing antibodies with higher titers earlier. All these data not only provide a live-attenuated vaccine candidate against the highly pathogenic FAdV-4 but also give a potential insertion site for developing FAdV-4-based vaccine vectors for delivering foreign antigens.


Assuntos
Infecções por Adenoviridae/veterinária , Aviadenovirus/fisiologia , Galinhas , Doenças das Aves Domésticas/prevenção & controle , Vacinas Virais/administração & dosagem , Infecções por Adenoviridae/prevenção & controle , Infecções por Adenoviridae/virologia , Animais , Sistemas CRISPR-Cas , Edição de Genes , Genes Virais , Doenças das Aves Domésticas/virologia , Sorogrupo , Vacinas Atenuadas/administração & dosagem
14.
Arch Virol ; 166(5): 1477-1480, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33616725

RESUMO

We determined the genomic sequence of a Ukrainian strain of fowl adenovirus B (FAdV-B). The isolate (D2453/1) shared 97.2% to 98.4% nucleotide sequence identity with other viruses belonging to the species Fowl aviadenovirus B. Marked genetic divergence was seen in the hexon, fiber, and ORF19 genes, and phylogenetic analysis suggested that recombination events had occurred in these regions. Our analysis revealed mosaicism in the recombination patterns, a finding that has also been described in the genomes of strains of FAdV-D and FAdV-E. The shared recombination breakpoints, affecting the same genomic regions in viruses belonging to different species, suggest that similar selection mechanisms are acting on the key neutralization antigens and epitopes in viruses of different FAdV species.


Assuntos
Infecções por Adenoviridae/veterinária , Aviadenovirus/genética , Galinhas/virologia , Genoma Viral/genética , Doenças das Aves Domésticas/virologia , Infecções por Adenoviridae/virologia , Animais , Aviadenovirus/classificação , Mapeamento Cromossômico , DNA Viral/genética , Variação Genética , Recombinação Homóloga , Filogenia , Proteínas Virais/genética
15.
Avian Pathol ; 50(2): 182-189, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33410705

RESUMO

Fowl adenoviruses (FAdV) are important infectious pathogens responsible for causing substantial economic losses to the poultry industry worldwide. One hundred and forty-six FAdV strains were continuously collected and analysed from 2013 to 2019 to understand the epidemiological change and nature of the virus in South Korea from two different standpoints, before and after the release of multiple commercial FAdV-4 vaccines. Phylogenetic analysis of the hexon loop-1 gene sequences showed that 92 strains belonged to FAdV-C (63%), 35 strains to FAdV-E (24%), 18 strains to FAdV-D (12.3%), and one strain to FAdV-A (0.7%), respectively. We provide evidence that the dominant FAdV serotype has recently changed from FAdV-4 to FAdV-8b, as reflected in the proportion of each serotype in field cases in 2019 (18.5% and 77.8%, respectively). The newly emerged FAdV-8b cluster was significantly noticeable compared to the old FAdV clusters, indicating that the development of a vaccine for FAdV-8b may be necessary. Overall, this new insight into FAdV prevalence provides a foundation for strategic control and the development of efficient vaccines against FAdV cases in chickens in South Korea.RESEARCH HIGHLIGHTS The dominant FAdV serotype in South Korea shifted from FAdV-4 to FAdV-8b in 2013-2019.A new cluster of FAdV-8b has emerged in South Korea, indicating the development of new vaccines.


Assuntos
Infecções por Adenoviridae/veterinária , Aviadenovirus/imunologia , Proteínas do Capsídeo/metabolismo , Galinhas/virologia , Doenças das Aves Domésticas/epidemiologia , Vacinas Virais/imunologia , Infecções por Adenoviridae/epidemiologia , Infecções por Adenoviridae/virologia , Animais , Aviadenovirus/genética , Proteínas do Capsídeo/genética , Proteção Cruzada , Filogenia , Doenças das Aves Domésticas/virologia , República da Coreia/epidemiologia , Sorogrupo
16.
Transbound Emerg Dis ; 68(2): 283-288, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32657542

RESUMO

Outbreaks of hydropericardium syndrome and inclusion body hepatitis caused by fowl adenovirus (FAdV) have occurred in China since June 2015, resulting in significant economic loss to poultry industry. In this study, a novel FAdV, designated as AH720, with recombination among serotype FAdV-8a and FAdV-8b was isolated and characterized in China. Full genome analysis revealed that the AH720 has the genome backbone from FAdV-8b and the fibre gene from FAdV-8a. In an infection study, although AH720 was not lethal to chickens, AH720 did cause characteristic lesions of inclusion body hepatitis in the infected chickens. All these data not only provide strong evidences for the recombination among different serotype FAdVs, but also highlight the necessary for monitoring the molecular epidemiology of such recombinant FAdV to develop efficient strategies against FAdV.


Assuntos
Infecções por Adenoviridae/veterinária , Aviadenovirus/fisiologia , Galinhas , Doenças das Aves Domésticas/virologia , Infecções por Adenoviridae/virologia , Animais , Aviadenovirus/classificação , Aviadenovirus/genética , China , Genoma Viral
17.
J Virol ; 95(6)2021 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-33361420

RESUMO

Fowl adenovirus serotype 4 (FAdV-4) is a hepatotropic virus that causes severe hepatic damage characterized by basophilic intranuclear inclusion bodies, vacuolar degeneration, and multifocal necrosis in hepatocytes. Many aspects of FAdV-4 infection and pathogenesis, however, remain unknown. Here, we found that FAdV-4-induced hepatic injury is accompanied by the accumulation of oil droplets (triglycerides) in the cytoplasm of hepatocytes, a typical indicator of steatosis, in FAdV-4-infected chickens. Significant upregulation of adipose synthesis-related genes, such as liver X receptor-α (LXR-α), peroxisome proliferator-activated receptor gamma (PPAR-γ), and sterol regulatory element-binding protein-1c (SREBP-1c), and significant downregulation of low-density lipoprotein secretion-related genes and lipid oxidation- and lipid decomposition-related genes were observed in the infected chickens. FAdV-4 infection in cultured leghorn male hepatoma (LMH) cells caused similar signs of steatosis, with alterations in various lipogenesis-related genes. We eliminated the effect of LXR-α activation on FAdV-4-induced steatosis and found that treatment with an LXR-α antagonist (SR9243) and RNA interference (small interfering RNA targeting LXR-α [Si-LXR-α]) decreased the number of oil droplets and the accumulation of lipogenic genes, but treatment with an LXR-α agonist (T0901317) increased the number of oil droplets and the accumulation of lipogenic genes in the cells. Additionally, SR9243 treatment or Si-LXR-α transfection led to significant reductions in viral DNA level, protein expression, and virus production, whereas T0901317 treatment caused significant increases in viral DNA level, protein expression, and virus production. However, inhibition of SREBP-1c activity had no significant effect on virus production. Collectively, these results indicated that FAdV-4-induced steatosis involves activation of the LXR-α signaling pathway, which might be a molecular mechanism underlying the hepatic injury associated with FAdV-4 infection.IMPORTANCE Fowl adenovirus serotype 4 (FAdV-4) is an important hepatotropic adenovirus in chicken, but the underlying mechanism of FAdV-4-induced hepatic injury remains unclear. We report here that infection with FAdV-4 induced the accumulation of oil droplets (triglycerides) in the cytoplasm of hepatocytes, a typical indicator of steatosis, in the livers of chickens. FAdV-4-induced steatosis might be caused by a disrupted balance of fat metabolism, as evidenced by differential regulation of various lipase genes. The significant upregulation of liver X receptor-α (LXR-α) prompted us to investigate the interplay between LXR-α activation and FAdV-4-induced steatosis. Treatment with an agonist, an antagonist, or RNA interference targeting LXR-α in cultured leghorn male hepatoma (LMH) cells indicated that FAdV-4-induced steatosis was dependent upon LXR-α activation, which contributed to virus replication. These results provide important mechanistic insights, revealing that FAdV-4 induces hepatic steatosis by activating the LXR-α signaling pathway and highlighting the therapeutic potential of strategies targeting the LXR-α pathway for the treatment of FAdV-4 infection.


Assuntos
Infecções por Adenoviridae/metabolismo , Aviadenovirus/patogenicidade , Fígado Gorduroso/metabolismo , Receptores X do Fígado/metabolismo , Infecções por Adenoviridae/virologia , Animais , Aviadenovirus/fisiologia , Linhagem Celular Tumoral , Galinhas , Fígado Gorduroso/virologia , Regulação da Expressão Gênica , Hepatócitos/metabolismo , Metabolismo dos Lipídeos/genética , Fígado/metabolismo , Fígado/patologia , Receptores X do Fígado/genética , Sorogrupo , Transdução de Sinais , Triglicerídeos/metabolismo , Replicação Viral
18.
J Vet Med Sci ; 83(1): 130-133, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33311002

RESUMO

We have developed a polymerase chain reaction (PCR) assay to facilitate detection of the major disease-associated serotypes of fowl adenovirus (FAdV) including serotypes 1, 2, 4, 8a and 8b; primers were designed based on serotype-specific sequences of the hexon gene. We tested field isolates from chickens diagnosed with inclusion body hepatitis, gizzard erosion and hydropericardium syndrome together with reference FAdV strains characterized in Japan. We found that the primers were serotype specific; appropriate amplification of serotype-specific hexon genes was confirmed by sequence analysis of the PCR products. This PCR assay will be useful for detection of FAdV and for differentiation between disease-associated serotypes.


Assuntos
Infecções por Adenoviridae , Aviadenovirus , Doenças das Aves Domésticas , Infecções por Adenoviridae/diagnóstico , Infecções por Adenoviridae/veterinária , Animais , Aviadenovirus/genética , Galinhas , Japão , Filogenia , Reação em Cadeia da Polimerase/veterinária , Doenças das Aves Domésticas/diagnóstico , Sorogrupo
19.
Poult Sci ; 99(11): 5983-5990, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33142516

RESUMO

Outbreaks of inclusion body hepatitis (IBH) and adenoviral gizzard erosion have been anecdotally reported in Greece since approximately 2011. However, a relevant increase in clinical outbreaks compatible with IBH has been described since 2014. Unfortunately, with limited exceptions, only serological assays were performed, and involved strains were not properly characterized. In the present study, 35 outbreaks were investigated in the period between July 2017 and February 2018 in Greece. In addition to clinical and histopathological diagnosis, fowl adenovirus (FAdV) presence was investigated by PCR and sequencing. Thirty-four out of 35 samples tested FAdV positive. Twenty-nine (85.29%) and 5 (14.71%) strains were classified as FAdV-E and FAdV-D, respectively. Fowl adenovirus-E strains were genetically homogeneous and formed an independent cluster of Greek-only sequences, including the sole previously available sequence, suggesting the prolonged circulation of this species in Greece. On the contrary, FAdV-D strains were more heterogeneous and closely related to strains sampled in other European countries, testifying the occurrence of multiple introduction events. The evaluation of phylogenetic relationships, geographic clustering, age of infection, and origin of the broiler breeder flocks suggests that both vertical and horizontal transmission are important in FAdV epidemiology in Greece and highlights the limited efficacy of currently implemented control measures. Of note, a significantly higher mortality was observed in precociously infected flocks, likely because of the higher susceptibility of younger animals. This evidence stresses the need of preventing vertical and/or early infection to limit the economic impact of adenovirus-induced diseases.


Assuntos
Infecções por Adenoviridae , Aviadenovirus , Epidemiologia Molecular , Doenças das Aves Domésticas , Infecções por Adenoviridae/epidemiologia , Infecções por Adenoviridae/microbiologia , Infecções por Adenoviridae/veterinária , Animais , Aviadenovirus/classificação , Aviadenovirus/genética , Galinhas , Europa (Continente) , Grécia/epidemiologia , Filogenia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/microbiologia
20.
Poult Sci ; 99(12): 6446-6453, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33248559

RESUMO

Fowl adenovirus (FAdV) has posed a grave threat to the health of poultry, and the sudden outbreak highlights the importance of the new rapid diagnostic method for the control and prevention of transmission. Hence, in the present study, a novel recombinase polymerase amplification (RPA) assay, which was suitable for all 12 serotypes (FAdV-1 to 8a and 8b to 11) had been successfully launched to detect FAdV. Also, the entire amplification process could be completed in the isothermal condition when temperature ranged from 26 to 42°C within no more than 14 min, which was remarkably superior to endpoint polymerase chain reaction (98 min) with the same detecting sensitivity (as low as 0.1 fg viral DNA), avoiding sophisticated thermal cyclers with simple operation. Additionally, the same primers did not produce positive reactions with other viruses tested, demonstrating that the specificity of the RPA assay was acceptable. Moreover, this developed method could be efficiently used in the diagnosis of FAdV references and epidemic strains from different avian origins, thus making it a rapid, reliable, and point-of-care FAdV diagnostics tool, as well as an alternative to endpoint PCR.


Assuntos
Aviadenovirus , Epidemias , Doenças das Aves Domésticas , Animais , Aviadenovirus/genética , Técnicas de Amplificação de Ácido Nucleico/veterinária , Aves Domésticas , Doenças das Aves Domésticas/diagnóstico , Doenças das Aves Domésticas/epidemiologia , Recombinases , Sensibilidade e Especificidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...