RESUMO
Avian leukemia virus subgroup J (ALV-J) causes various diseases associated with tumor formation and decreased fertility and induced immunosuppressive disease, resulting in significant economic losses in the poultry industry globally. Virus usually exploits the host cellular machinery for their replication. Although there are increasing evidences for the cellular proteins involving viral replication, the interaction between ALV-J and host proteins leading to the pivotal steps of viral life cycle are still unclear. Here, we reported that ribonucleoside-diphosphate reductase subunit M2 (RRM2) plays a critical role during ALV-J infection by interacting with capsid protein P27 and activating Wnt/ß-catenin signaling. We found that the expression of RRM2 is effectively increased during ALV-J infection, and that RRM2 facilitates ALV-J replication by interacting with viral capsid protein P27. Furthermore, ALV-J P27 activated Wnt/ß-catenin signaling by promoting ß-catenin entry into the nucleus, and RRM2 activated Wnt/ß-catenin signaling by enhancing its phosphorylation at Ser18 during ALV-J infection. These data suggest that the upregulation of RRM2 expression by ALV-J infection favors viral replication in host cells via activating Wnt/ß-catenin signaling. IMPORTANCE Our results revealed a novel mechanism by which RRM2 facilitates ALV-J growth. That is, the upregulation of RRM2 expression by ALV-J infection favors viral replication by interacting with capsid protein P27 and activating Wnt/ß-catenin pathway in host cells. Furthermore, the phosphorylation of serine at position 18 of RRM2 was verified to be the important factor regulating the activation of Wnt/ß-catenin signaling. This study provides insights for further studies of the molecular mechanism of ALV-J infection.
Assuntos
Vírus da Leucose Aviária , Leucose Aviária , Ribonucleosídeo Difosfato Redutase , Via de Sinalização Wnt , Animais , Vírus da Leucose Aviária/metabolismo , beta Catenina/metabolismo , Proteínas do Capsídeo/metabolismo , Galinhas , Ribonucleosídeo Difosfato Redutase/metabolismoRESUMO
In this paper, we present a novel approach for calculating the heat distribution within a processed workpiece subjected to laser irradiation while accounting for the influence of bottom water vapor. A comprehensive mathematical model is introduced and numerical techniques using difference approximation are employed. Initially, the three-dimensional heat equation, originally defined in the rectangular coordinate system, is transformed into a corresponding model within the cylindrical coordinate system, incorporating a nonlinear boundary condition to account for coupling effects. Subsequently, leveraging the axial symmetry of the heat distribution, the three-dimensional model is simplified into a two-dimensional one. This simplified model is solved using the alternating direction implicit scheme coupled with the Crank-Nicolson method. Moreover, we develop a high-precision numerical treatment for the nonlinear boundary condition within the cylindrical coordinate system. To validate our methodology, simulation experiments are conducted on three distinct samples. Our comparative results demonstrate the feasibility and efficiency of the proposed approach in the context of water-jet guided laser processing.
RESUMO
Infectious bursal disease virus (IBDV) causes an acute and highly contagious infectious disease characterized by severe immunosuppression, causing great economic losses to the poultry industry globally. Over the past 30 years, this disease has been well controlled through vaccination and strict biosafety measures. However, novel variant IBDV strains have emerged in recent years, posing a new threat to the poultry industry. Our previous epidemiological survey showed that few novel variant IBDV strains had been isolated from chickens immunized with the attenuated live vaccine W2512-, suggesting that this vaccine is efficacious against novel variant strains. Here, we report the protective effect of the W2512 vaccine against novel variant strains in SPF chickens and commercial yellow-feathered broilers. We found that W2512 causes severe atrophy of the bursa of Fabricius in SPF chickens and commercial yellow-feathered broilers, induces high levels of antibodies against IBDV, and protects chickens from infection with the novel variant strains via a placeholder effect. This study highlights the protective effect of commercial attenuated live vaccines against the novel IBDV variant and provides guidance for the prevention and control of this disease.
Assuntos
Infecções por Birnaviridae , Vírus da Doença Infecciosa da Bursa , Doenças das Aves Domésticas , Vacinas Virais , Animais , Galinhas , Vacinas Virais/genética , Infecções por Birnaviridae/prevenção & controle , Infecções por Birnaviridae/veterinária , Vacinas Atenuadas/genética , Anticorpos Antivirais , Bolsa de FabriciusRESUMO
Pseudorabies virus (PRV), the causative agent of Aujeszky's disease, has gained increased attention in China in recent years as a result of a recent outbreak of pseudorabies. The causative agent has a wide spectrum of hosts, including pigs, cattle, sheep, dogs, cats, bats, bears, and even some avian species. Although dog-related cases of pseudorabies have been reported regularly, many cases are overlooked, and few PRV strains are isolated because death occurs rapidly after PRV infection and veterinarians often do not test for PRV in dogs. Here, we performed a retrospective detection of PRV in dogs from July 2017 to December 2018. We found that PRV (including gE-deleted strains, classical strains, and variant strains) is prevalent in dogs regardless of season and region and that the epidemic PRV strains in dogs share high sequence similarity with gC and gE genes of swine epidemic strains and commercial vaccine strains. Collectively, our findings underscore the importance of PRV surveillance in dogs, which is beneficial for understanding the epidemiology of PRV in dogs and assists in efforts aimed at effectively controlling this disease.
Assuntos
Herpesvirus Suídeo 1/genética , Pseudorraiva/virologia , Animais , China , Surtos de Doenças , Cães , Genes Virais/genética , Genômica/métodos , Filogenia , Estudos RetrospectivosRESUMO
Chicken anemia virus (CAV) causes severe anemia and immunosuppression in young chickens and a compromised immune response in older birds, resulting in great economic losses to the poultry industry worldwide. Here, we report the molecular epidemiology and characterization of CAV circulating in poultry in Guangdong province, China. Ninety-one of 277 chickens collected from 2016 to 2017 were CAV positive. Full-genome sequencing revealed the presence of eight separate strains. Phylogenetic analysis based on the genome sequences obtained in this study and related sequences available in the GenBank database showed that all of the CAV isolates exhibit a close relationship to each other and belong to the same genotypic group. Putative recombination events were also detected in the genomes of the newly isolated CAVs. Collectively, our findings underscore the importance of CAV surveillance and provide information that will lead to a better understanding of the evolution of CAV.
Assuntos
Vírus da Anemia da Galinha/classificação , Infecções por Circoviridae/veterinária , Variação Genética , Genótipo , Doenças das Aves Domésticas/virologia , Recombinação Genética , Animais , Sequência de Bases , Vírus da Anemia da Galinha/isolamento & purificação , Galinhas , China/epidemiologia , Infecções por Circoviridae/virologia , Epidemiologia Molecular , Filogenia , Análise de Sequência de DNA/veterináriaRESUMO
The group of highly related avian leukosis viruses (ALVs) in chickens are thought to have evolved from a common retroviral ancestor into six subgroups, A to E and J. These ALV subgroups use diverse cellular proteins encoded by four genetic loci in chickens as receptors to gain entry into host cells. Hosts exposed to ALVs might be under selective pressure to develop resistance to ALV infection. Indeed, resistance alleles have previously been identified in all four receptor loci in chickens. The tvb gene encodes a receptor, which determines the susceptibility of host cells to ALV subgroup B (ALV-B), ALV-D, and ALV-E. Here we describe the identification of two novel alleles of the tvb receptor gene, which possess independent insertions each within exon 4. The insertions resulted in frameshift mutations that reveal a premature stop codon that causes nonsense-mediated decay of the mutant mRNA and the production of truncated Tvb protein. As a result, we observed that the frameshift mutations in the tvb gene significantly lower the binding affinity of the truncated Tvb receptors for the ALV-B, ALV-D, and ALV-E envelope glycoproteins and significantly reduce susceptibility to infection by ALV-B, ALV-D and ALV-E in vitro and in vivo Taken together, these findings suggest that frameshift mutation can be a molecular mechanism of reducing susceptibility to ALV and enhance our understanding of virus-host coevolution.IMPORTANCE Avian leukosis virus (ALV) once caused devastating economic loss to the U.S. poultry industry prior the current eradication schemes in place, and it continues to cause severe calamity to the poultry industry in China and Southeast Asia, where deployment of a complete eradication scheme remains a challenge. The tvb gene encodes the cellular receptor necessary for subgroup B, D, and E ALV infection. Two tvb allelic variants that resulted from frameshift mutations have been identified in this study, which have been shown to have significantly reduced functionality in mediating subgroup B, D, and E ALV infection. Unlike the control of herpesvirus-induced diseases by vaccination, the control of avian leukosis in chickens has relied totally on virus eradication measures and host genetic resistance. This finding enriches the allelic pool of the tvb gene and expands the potential for genetic improvement of ALV resistance in varied chicken populations by selection.
Assuntos
Vírus da Leucose Aviária/metabolismo , Leucose Aviária , Proteínas Aviárias , Galinhas , Mutação da Fase de Leitura , Predisposição Genética para Doença , Receptores Virais , Animais , Leucose Aviária/genética , Leucose Aviária/metabolismo , Vírus da Leucose Aviária/genética , Proteínas Aviárias/genética , Proteínas Aviárias/metabolismo , Linhagem Celular , Galinhas/genética , Galinhas/metabolismo , Galinhas/virologia , Receptores Virais/genética , Receptores Virais/metabolismoRESUMO
BACKGROUND: As a low pathogenic influenza virus, avian influenza virus subtype H9N2 (H9N2 AIV) often induces high morbidity in association with secondary bacterial infections in chickens or mammals. To explore this phenomenon, the relationship between intestinal microflora changes and bacterial translocations was studied post H9N2 AIV challenge and post AIV infection plus Ageratum-liquid treatment. METHODS: Illumina sequencing, histological examination and Neongreen-tagged bacteria were used in this study to research the microbiota composition, intestinal barrier, and bacterial translocation in six weeks of BALB/c mice. RESULTS: H9N2 AIV infection caused intestinal dysbacteriosis and mucosal barrier damages. Notably, the villus length was significantly reduced (p < 0.01) at 12 dpi and the crypt depth was significantly increased (p < 0.01) at 5 dpi and 12 dpi with infection, resulting in the mucosal regular villus-length/crypt-depth (V/C) was significantly reduced (p < 0.01) at 5 dpi and 12 dpi. Moreover, degeneration and dissolution of the mucosal epithelial cells, loose of the connective tissue and partial glandular atrophy were found in infection group, indicating that intestinal barrier function was weakened. Eventually, intestinal microbiota (Staphylococcus, E. coli, etc.) overrun the intestinal barrier and migrated to liver and lung tissues of the mice at 5 and 12 dpi. Furthermore, the bacteria transferred in mesentery tissue sites from intestine at 36 h through tracking the Neongreen-tagged bacteria. Then the Neongreen-tagged bacteria were isolated from liver at 48 h post intragastrical administration. Simultaneously, Ageratum-liquid could inhibit the intestinal microbiota disorder post H9N2 AIV challenge via the respiratory tract. In addition, this study also illustrated that Ageratum-liquid could effectively prevent intestinal bacterial translocation post H9N2 AIV infection in mice. CONCLUSION: In this study, we report the discovery that H9N2 AIV infection could damage the ileal mucosal barrier and induce the disturbance of the intestinal flora in BALB/c mice resulting in translocation of intestinal bacteria. In addition, this study indicated that Ageratum-liquid can effectively prevent bacterial translocation following H9N2 infection. These findings are of important theoretical and practical significance in prevention and control of H9N2 AIV infection.
Assuntos
Ageratum/química , Infecções Bacterianas/tratamento farmacológico , Translocação Bacteriana/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Mucosa Intestinal/virologia , Infecções por Orthomyxoviridae/tratamento farmacológico , Animais , Coinfecção/tratamento farmacológico , Microbioma Gastrointestinal , Genoma Bacteriano , Vírus da Influenza A Subtipo H9N2/patogenicidade , Vírus da Influenza A Subtipo H9N2/fisiologia , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Circular RNAs (circRNAs) are evolutionarily conserved and widely present, but their functions remain largely unknown. Recent development has highlighted the importance of circRNAs as the sponge of microRNA (miRNA) in cancer. We previously reported that gga-miR-375 was downregulated in the liver tumors of chickens infected with avian leukosis virus subgroup J (ALV-J) by microRNA microarray assay. It can be reasonably assumed in accordance with previous studies that the gga-miR-375 may be related to circRNAs. However, the question as to which circRNA acts as the sponge for gga-miR-375 remains to be answered. In this study, circRNA sequencing results revealed that a circRNA Vav3 termed circ-Vav3 was upregulated in the liver tumors of chickens infected with ALV-J. In addition, RNA immunoprecipitation (RIP), biotinylated RNA pull-down and RNA-fluorescence in situ hybridization (RNA-FISH) experiments were conducted to confirm that circ-Vav3 serves as the sponge of gga-miR-375. Furthermore, we confirmed through dual luciferase reporter assay that YAP1 is the target gene of gga-miR-375. The effect of the sponge function of circ-Vav3 on its downstream genes has been further verified by our conclusion that the sponge function of circ-Vav3 can abrogate gga-miR-375 target gene YAP1 and increase the expression level of YAP1. We further confirmed that the circ-Vav3/gga-miR-375/YAP1 axis induces epithelial-mesenchymal transition (EMT) through influencing EMT markers to promote tumorigenesis. Finally, clinical ALV-J-induced tumor livers were collected to detect core gene expression levels to provide a proof to the concluded tumorigenic mechanism. Together, our results suggest that circ-Vav3/gga-miR-375/YAP1 axis is another regulator of tumorigenesis.
Assuntos
Transição Epitelial-Mesenquimal/genética , MicroRNAs/genética , Interferência de RNA , RNA/genética , Regiões 3' não Traduzidas , Animais , Leucose Aviária/complicações , Leucose Aviária/virologia , Sítios de Ligação , Movimento Celular/genética , Galinhas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , RNA CircularRESUMO
Avian encephalomyelitis virus (AEV) causes typical neurological symptoms in young chicks and a transient drop in egg production and hatchability in adult laying birds, resulting in huge economic losses in the poultry industry. An effective way to control and prevent this disease is vaccination of the flocks. Here, we assessed the efficacy of the live vaccine candidate strain GDt29 against avian encephalomyelitis virus. The GDt29 strain has low virulence, was confirmed safe, and showed no signs of pathogenicity. High titers of AEV-specific antibodies were detected in GDt29-vaccinated hens (S/P > 3.0) and their progeny (S/P > 2.0). Moreover, the eggs of GDt29-vaccinated hens with high levels of maternal antibodies were hatched successfully regardless of challenge with a heterologous AEV strain, and the GDt29 attenuated vaccine showed higher protective efficacy against AEV than the commercial vaccine. Furthermore, contact-exposed chicks bred with GDt29-vaccinated birds generated high titers against AE virus (S/P > 2.8). Collectively, our studies are proof of the principle that GDt29 might be an ideal vaccine candidate to prevent AEV infection, and they highlight the utility of using a live vaccine against AEV.
Assuntos
Vírus da Encefalomielite Aviária/imunologia , Infecções por Picornaviridae/prevenção & controle , Doenças das Aves Domésticas/prevenção & controle , Vacinas Atenuadas/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/imunologia , Galinhas , Vírus da Encefalomielite Aviária/genética , Feminino , Infecções por Picornaviridae/imunologia , Infecções por Picornaviridae/virologia , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/virologia , Vacinação , Vacinas Atenuadas/administração & dosagem , Vacinas Virais/administração & dosagemRESUMO
Infectious bursal disease (IBD) is an acute, highly contagious, and immunosuppressive avian disease caused by IBD virus (IBDV). Our previous report indicates that IBDV VP5 induces apoptosis via interaction with voltage-dependent anion channel 2 (VDAC2). However, the underlying molecular mechanism is still unclear. We report here that receptor of activated protein kinase C 1 (RACK1) interacts with both VDAC2 and VP5 and that they could form a complex. We found that overexpression of RACK1 inhibited IBDV-induced apoptosis in DF-1 cells and that knockdown of RACK1 by small interfering RNA induced apoptosis associated with activation of caspases 9 and 3 and suppressed IBDV growth. These results indicate that RACK1 plays an antiapoptotic role during IBDV infection via interaction with VDAC2 and VP5, suggesting that VP5 sequesters RACK1 and VDAC2 in the apoptosis-inducing process.
Assuntos
Proteínas de Ligação ao GTP/fisiologia , Vírus da Doença Infecciosa da Bursa/fisiologia , Proteínas de Neoplasias/fisiologia , Receptores de Superfície Celular/fisiologia , Proteínas não Estruturais Virais/fisiologia , Replicação Viral , Canal de Ânion 2 Dependente de Voltagem/metabolismo , Animais , Galinhas , Expressão Gênica , Células HEK293 , Humanos , Domínios e Motivos de Interação entre Proteínas , Transporte Proteico , Receptores de Quinase C AtivadaRESUMO
Members of avian leukosis virus subgroup J (ALV-J) cause various diseases associated with tumor formation and decreased fertility, resulting in major economic losses in the poultry industry worldwide. To assess the status of ALV-J infection in meat-type chickens in southern China, the molecular epidemiology of ALV-J strains was investigated. A total of 265 clinical samples collected from southern China from 2013 to 2014 were investigated in this study for the presence of ALV-J, which resulted in 12 virus isolates. Phylogenetic analysis showed that 91.7 % (11/12) of the ALV-J isolates have possessed high homology to Chinese layer isolates and belong to one subgroup. One of the ALV isolates (designated GD1411-1) was relatively closely related to the ALV-J broiler isolates, indicating that the GD1411-1 isolate might be a transition strain. Several unique nucleotide substitutions in gp85 and the U3 region were detected in all 12 ALV-J isolates. This study provides some interesting information on the molecular characterization of ALV-J isolates. These findings will be beneficial for understanding of the pathogenic mechanism of ALV-J infection.
Assuntos
Vírus da Leucose Aviária/classificação , Vírus da Leucose Aviária/isolamento & purificação , Leucose Aviária/epidemiologia , Leucose Aviária/virologia , Genótipo , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/virologia , Animais , Vírus da Leucose Aviária/genética , Galinhas , China/epidemiologia , Epidemiologia Molecular , Filogenia , Mutação Puntual , Análise de Sequência de DNARESUMO
Avian leukosis virus (ALV) causes high mortality associated with tumor formation and decreased fertility, and results in major economic losses in the poultry industry worldwide. Recently, a putative novel ALV subgroup virus named ALV-K was observed in Chinese local chickens. In this study, a novel ALV strain named GD14LZ was isolated from a Chinese local yellow broiler in 2014. The proviral genome was sequenced and phylogenetically analyzed. The replication ability and pathogenicity of this virus were also evaluated. The complete proviral genome sequence of GD14LZ was 7482 nt in length, with a genetic organization typical of replication-competent type C retroviruses lacking viral oncogenes. Sequence analysis showed that the gag, pol and gp37 genes of GD14LZ have high sequence similarity to those of other ALV strains (A-E subgroups), especially to those of ALV-E. The gp85 gene of the GD14LZ isolate showed a low sequence similarity to those other ALV strains (A-E subgroups) but showed high similarity to strains previously described as ALV-K. Phylogenetic analysis of gp85 also suggested that the GD14LZ isolate was related to ALV-K strains. Further study showed that this isolate replicated more slowly and was less pathogenic than other ALV strains. These results indicate that the GD14LZ isolate belongs to the novel subgroup ALV-K and probably arose by recombination of ALV-K with endogenous viruses with low replication and pathogenicity. This virus might have existed in local Chinese chickens for a long time.
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Vírus da Leucose Aviária/genética , Vírus da Leucose Aviária/isolamento & purificação , Galinhas/virologia , Evolução Molecular , Variação Genética , Provírus/genética , Provírus/isolamento & purificação , Animais , Vírus da Leucose Aviária/classificação , Vírus da Leucose Aviária/fisiologia , China , Análise por Conglomerados , DNA Viral/genética , Genoma Viral , Filogenia , Análise de Sequência de DNA , Homologia de Sequência , Replicação ViralRESUMO
Avian reovirus (ARV) causes viral arthritis, chronic respiratory diseases, retarded growth and malabsorption syndrome. It is well established that the ARV sigma-C protein induces apoptosis in host cells. However, the underlying molecular mechanism of this induction is still unclear. We report here the identification of eukaryotic elongation factor 1 alpha 1 (EEF1A1) as the interacting partner of σC. We found that σC-induced apoptosis in DF-1 cells could be completely abolished by knockdown of EEF1A1 by siRNA. Furthermore, knockdown of EEF1A1 markedly reduced ARV-induced apoptosis associated with decreased caspase-9 and -3 activation and cytochrome C release, leading to increased ARV growth in host cells. Thus, EEF1A1 plays a critical role in σC-induced apoptosis and inhibition of viral growth.
Assuntos
Apoptose , Proteínas do Capsídeo/fisiologia , Fator de Iniciação 1 em Eucariotos/fisiologia , Orthoreovirus Aviário/fisiologia , Infecções por Reoviridae/fisiopatologia , Animais , Apoptose/fisiologia , Western Blotting , Caspase 3/metabolismo , Caspase 9/metabolismo , Linhagem Celular , Embrião de Galinha/virologia , Imunofluorescência , Células HEK293/virologia , Humanos , Imunoprecipitação , Microscopia Confocal , Orthoreovirus Aviário/crescimento & desenvolvimento , Fator 1 de Elongação de Peptídeos/fisiologia , Infecções por Reoviridae/veterinária , Infecções por Reoviridae/virologia , Técnicas do Sistema de Duplo-HíbridoRESUMO
An outbreak of duck astrovirus (DAstV) has occurred in duck farming regions of China, causing substantial economic setbacks in the duck industry. This investigation aimed to examine the variations in DAstV pathogenicity among ducks at different age intervals. Infections were induced in ducks at distinct age groups (1, 7, 14, 21, and 28 d) utilizing the DAstv-1-GDB-2022 strain. The results indicate increased pathogenicity of the DAstv-1-GDB-2022 strain in ducklings aged 21 to 28 d, manifesting as liver and kidney enlargement, severe bleeding, and potential fatalities. Conversely, ducklings aged 1 and 14 d displayed milder symptoms postinfection. Notably, viral shedding continued in ducks of diverse age groups even 21 d postinfection (Dpi). Moreover, DAstV replicates in various tissues, predominantly affecting the liver. Immunohistochemical tests using rabbit anti-DAstV antibodies revealed robust positive signals in both the liver and kidneys, which correlated with the clinical symptom severity observed through macroscopic and microscopic examinations. Serum biochemical assays and indirect ELISA demonstrated a consistent response to DAstV infection across different age groups, with older ducklings exhibiting increased sensitivity. In conclusion, this study successfully replicated clinical symptoms similar to those of natural DAstV infection using the DAstv-1-GDB-2022 strain. Importantly, we systematically delineated the differences in susceptibility to DAstV among ducks at various ages, laying the foundation for further research into the pathogenic mechanisms of DAstV and potential vaccine development.
Assuntos
Infecções por Astroviridae , Avastrovirus , Patos , Doenças das Aves Domésticas , Animais , Patos/virologia , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/patologia , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Avastrovirus/fisiologia , Fatores Etários , Suscetibilidade a Doenças/veterinária , Suscetibilidade a Doenças/virologia , China/epidemiologiaRESUMO
Infectious bursal disease virus (IBDV) caused an acute and highly contagious infectious disease characterized by severe immunosuppression, causing considerable economic losses to the poultry industry globally. Although this disease was well-controlled under the widely use of commercial vaccines in the past decades, the novel variant IBDV strains emerged recently because of the highly immunized-selection pressure in the field, posting new threats to poultry industry. Here, we reported novel variant IBDV is responsible for a disease outbreak, and assessed the epidemic and pathogenicity of IBDV in this study. Moreover, we constructed a challenge model using Fowl adenovirus serotype 4 (FAdV-4) to study on the immunosuppressive effect. Our findings underscore the importance of IBDV surveillance, and provide evidence for understanding the pathogenicity of IBDV.
Assuntos
Infecções por Birnaviridae , Vírus da Doença Infecciosa da Bursa , Doenças das Aves Domésticas , Animais , Galinhas , Virulência , Infecções por Birnaviridae/prevenção & controle , Infecções por Birnaviridae/veterinária , Vacinação/veterinária , Aves Domésticas , AdenoviridaeRESUMO
A suspected outbreak of duck astrovirus (DAstV) disease occurred in a large Muscovy duck farm in Guangdong Province, China, in June 2022, which severely affected the production performance and health of Muscovy ducks. This study aimed to investigate the prevalence of DAstV disease in Southeast China. Herein, we employed semi-nested PCR ethodto screen 5203 swab and liver samples from 11 Muscovy duck farms in 5 provinces of China for the presence of DAstV. Among them, 1356 samples (26.06%, 1356/5203) tested positive for DAstV, out of which 11 DAstV strains were isolated after 10 generations of blind transmission through Leghorn male hepatoma (LMH) cells and performed their whole-genome sequencing. The alignment results showed that the 11 DAstV isolates exhibited relatively low homology (15.4%-75%) with the astrovirus isolates from other species published in GenBank, whereas their homology (nucleotide: 90.4%-99.99%; amino acid: 94%-99.8%) with the DAstV type 1 (DAstV-1) reference strain was higher, indicating considerable homology. The results indicated that DAstV-1 was the main pathogenic factor. Herein, we successfully recreated the clinical symptoms of natural infection in 28-day-old specific-pathogen-free (SPF) ducks using the DAstV-1-GDB-2022 strain. The primary clinical manifestations included liver enlargement, hemorrhaging, and disruptions in liver function. Additionally, we confirmed the cross-species transmission potential of DAstV-1, marking the first occurrence of clinical symptoms of DAstV in 28-day-old SPF chickens. Our findings provide new perspectives on the epidemiology and pathogenicity of DAstV-1 and may help in advancing the development of DAstV vaccines.
RESUMO
MicroRNAs (miRNAs) involved host-virus interaction, affecting the replication or pathogenesis of several viruses. Frontier evidences suggested that miRNAs play essential roles in infectious bursal disease virus (IBDV) replication. However, the biological function of miRNAs and the underlying molecular mechanisms are still unclear. Here, we reported that gga-miR-20b-5p acted as a negative factor affecting IBDV infection. We found that gga-miR-20b-5p was significantly up-regulated during IBDV infection in host cells, and that gga-miR-20b-5p effectively inhibited IBDV replication via targeting the expression of host protein netrin 4 (NTN4). In contrast, inhibition of endogenous miR-20b-5p markedly facilitated viral replication associated with enhancing NTN4 expression. Collectively, these findings highlight a crucial role of gga-miR-20b-5p in IBDV replication.
Assuntos
Vírus da Doença Infecciosa da Bursa , MicroRNAs , Animais , Galinhas , Vírus da Doença Infecciosa da Bursa/genética , MicroRNAs/metabolismo , Interações entre Hospedeiro e Microrganismos , Netrinas , Replicação Viral/fisiologiaRESUMO
(1) Background: Group A rotaviruses (RVAs) are the primary cause of severe intestinal diseases in piglets. Porcine rotaviruses (PoRVs) are widely prevalent in Chinese farms, resulting in significant economic losses to the livestock industry. However, isolation of PoRVs is challenging, and their pathogenicity in piglets is not well understood. (2) Methods: We conducted clinical testing on a farm in Jiangsu Province, China, and isolated PoRV by continuously passaging on MA104 cells. Subsequently, the pathogenicity of the isolated strain in piglets was investigated. The piglets of the PoRV-infection group were orally inoculated with 1 mL of 1.0 × 106 TCID50 PoRV, whereas those of the mock-infection group were fed with an equivalent amount of DMEM. (3) Results: A G5P[23] genotype PoRV strain was successfully isolated from one of the positive samples and named RVA/Pig/China/JS/2023/G5P[23](JS). The genomic constellation of this strain was G5-P[23]-I5-R1-C1-M1-A8-N1-T1-E1-H1. Sequence analysis revealed that the genes VP3, VP7, NSP2, and NSP4 of the JS strain were closely related to human RVAs, whereas the remaining gene segments were closely related to porcine RVAs, indicating a reassortment between porcine and human strains. Furthermore, infection of 15-day-old piglets with the JS strain resulted in a diarrheal rate of 100% (8 of 8) and a mortality rate of 37.5% (3 of 8). (4) Conclusions: The isolated G5P[23] genotype rotavirus strain, which exhibited strong pathogenicity in piglets, may have resulted from recombination between porcine and human strains. It may serve as a potential candidate strain for developing vaccines, and its immunogenicity can be tested in future studies.
Assuntos
Infecções por Rotavirus , Rotavirus , Animais , China , Diarreia/veterinária , Diarreia/virologia , Rotavirus/genética , Rotavirus/isolamento & purificação , Rotavirus/patogenicidade , Suínos/virologia , Virulência/genética , Infecções por Rotavirus/genética , Infecções por Rotavirus/veterinária , Infecções por Rotavirus/virologiaRESUMO
Goose astroviruses (GoAstV) cause fatal gout and decrease product performance in the waterfowl industry across the world. Since no effective vaccines are available, studies on the epidemiology of the virus are necessary for vaccine development. In this study, we collected 94 gout samples from goose farms in the Guangdong Province of South China. Among them, 87 samples (92.6%) tested positive for GoAstV, out of which five GoAstV strains were isolated after four generations of blind transmission through healthy 13-day-old goose embryos. The whole genome of the isolates was sequenced and further analyzed by comparing the sequences with published sequences from China and other parts of the world. The results of the alignment analysis showed that nucleotide sequence similarities among the five GoAstV isolates were around 97.4-98.8%, 98.6-100%, 98.1-99.8%, and 96.7-100% for the whole genome, ORF1a, ORF1b, and ORF2, respectively. These results showed that the GoAstV isolates were highly similar to each other, although they were prevalent in five different regions of the Guangdong Province. The results of the phylogenetic analysis showed that the whole genome, along with the ORF1a, ORF1b, and ORF2 genes of the isolates, were clustered on a single branch, along with the recently published GoAstV-2, and were very distinct from the DNA sequences of the GoAstV-1 virus. In this study, we also reproduced the clinical symptoms of natural infection using the GoAstV-GD2101 isolates, confirming that the gout-causing pathogen in goslings was the goose astrovirus. These findings provided new insights into the pathogenicity and genetic evolution of GoAstV and laid the foundation for effectively controlling the disease.
RESUMO
A detailed analysis of the Ns1/Vp1Vp2 genome region of the porcine parvovirus (PPV) strains isolated from vaccinated animals was performed. We found many inconsistencies in the phylogenetic trees of these viral isolates, such as low statistical support and strains with long branches in the phylogenetic trees. Thus, we used distance-based and phylogenetic methods to distinguish de facto recombinants from spurious recombination signals. We found a mosaic virus in which the Ns1 gene was acquired from one PPV clade and the Vp1Vp2 gene was acquired from a distinct phylogenetic clade. We also described the interclade mosaic structure of the Vp1Vp2 gene of a reference strain. If recombination is an adaptive mechanism over the course of PPV evolution, we would likely observe increasing numbers of chimeric strains over time. However, when the PPV sequences isolated from 1964 to 2011 were analysed, only two chimeric strains were detected. Thus, PPV recombination is an independent event, resulting from close contact between animals housed in high-density conditions.