RESUMO
Wild waterfowl serve as a reservoir of some astroviruses. Fecal samples from wild waterfowl collected at Hong Kong's Marshes were tested using pan-astrovirus reverse transcription-PCR. Positive samples underwent subsequent host identification using DNA barcoding. Based on deduced partial sequences, noteworthy samples from three astrovirus groups (mammalian, avian and unclassified astroviruses) were further analyzed by next-generation sequencing. One sample of Avastrovirus 4 clade, MP22-196, had a nearly complete genome identified. The results of ORF2 phylogenetic analysis and genetic distance analysis indicate that Avastrovirus 4 is classified as a distinct subclade within Avastrovirus. MP22-196 has typical astrovirus genome characteristics. The unique characteristics and potential differences of this genome, compared to other avian astrovirus sequences, involve the identification of a modified sgRNA sequence situated near the ORF2 start codon, which precedes the ORF1b stop codon. Additionally, the 3' UTR of MP22-196 is shorter than other avian astroviruses. This study expands our understanding of the Avastrovirus 4 clade.
Assuntos
Infecções por Astroviridae , Aves , Fezes , Variação Genética , Genoma Viral , Filogenia , Animais , Hong Kong , Aves/virologia , Fezes/virologia , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Animais Selvagens/virologia , Doenças das Aves/virologia , Sequenciamento de Nucleotídeos em Larga Escala , Avastrovirus/genética , Avastrovirus/classificação , Avastrovirus/isolamento & purificação , RNA Viral/genética , Fases de Leitura Aberta , Astroviridae/genética , Astroviridae/isolamento & purificação , Astroviridae/classificaçãoRESUMO
Interferon-induced protein with tetratricopeptide repeats (IFITs), a family of proteins strongly induced by type I interferon (IFN-I), are deeply involved in many cellular and viral processes. IFIT5, the sole protein in this family found in birds, also plays a crucial role in regulating virus infection. In this study, goose IFIT5 (gIFIT5) was first cloned from peripheral blood lymphocyte (PBL) and phylogenetic analysis showed that it was highly homologous with duck IFIT5 (dIFIT5), sharing 94.6% identity in amino acid sequence. Subsequently, the expression kinetics of gIFIT5 during goose astrovirus (GAstV) infection and the regulatory effect of gIFIT5 on GAstV proliferation were evaluated. Results showed that the mRNA and protein expression level of gIFIT5 was greatly induced by GAstV infection, especially at 12 hpi. Importantly, gIFIT5 could conversely promote GAstV replication in GEF cells. Virus titers in gIFIT5 overexpression group were significantly higher than those in control group at 12 and 24 hpi. Western blot and quantitative real-time PCR (qRT-PCR) further demonstrated that the production of viral cap protein was significantly facilitated in gIFIT5-transfected group. Collectively, GAstV facilitates self-replication via promoting gIFIT5 expression.
Assuntos
Infecções por Astroviridae , Proteínas Aviárias , Gansos , Doenças das Aves Domésticas , Replicação Viral , Animais , Gansos/fisiologia , Gansos/virologia , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Doenças das Aves Domésticas/virologia , Proteínas Aviárias/genética , Proteínas Aviárias/metabolismo , Filogenia , Avastrovirus/fisiologia , Avastrovirus/genética , Sequência de Aminoácidos , Regulação da Expressão GênicaRESUMO
(1) Goose astrovirus (GAstV) is a novel emerging pathogen that causes significant economic losses in waterfowl farming. A convenient, sensitive, and specific detection method for GAstV in field samples is important in order to effectively control GAstV. Droplet digital polymerase chain reaction (ddPCR) is a novel, sensitive, good-precision, and absolute quantitation PCR technology which does not require calibration curves. (2) In this study, we developed a ddPCR system for the sensitive and accurate quantification of GAstV using the conserved region of the ORF2 gene. (3) The detection limit of ddPCR was 10 copies/µL, ~28 times greater sensitivity than quantitative real-time PCR (qPCR). The specificity of the test was determined by the failure of amplification of other avian viruses. Both ddPCR and qPCR tests showed good repeatability and linearity, and the established ddPCR method had high sensitivity and good specificity to GAstV. Clinical sample test results showed that the positive rate of ddPCR (88.89%) was higher than that of qPCR (58.33%). (4) As a result, our results suggest that the newly developed ddPCR method might offer improved analytical sensitivity and specificity in its GAstV measurements. The ddPCR could be widely applied in clinical tests for GAstV infections.
Assuntos
Infecções por Astroviridae , Avastrovirus , Gansos , Sensibilidade e Especificidade , Animais , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/diagnóstico , Infecções por Astroviridae/virologia , Gansos/virologia , Avastrovirus/genética , Avastrovirus/isolamento & purificação , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase/métodos , Reprodutibilidade dos Testes , Astroviridae/genética , Astroviridae/isolamento & purificação , Limite de DetecçãoRESUMO
Goose astrovirus genotype 1 (GAstV-1) has emerged in goose farms in some provinces of China in recent years and is considered to be one of the pathogens of gout in goslings in China. However, few studies have been conducted on the dynamic distribution, tissue tropism, and pathogenesis of GAstV-1 in goslings. In 2022, an epidemiological investigation of goose astrovirus (GAstV) in goslings was conducted in seven provinces of China. During the investigation, a GAstV-1 designated as GAstV-JSXZ was identified in the kidney of an 8-day-old gosling and was successfully isolated from a goose embryo. The full genome sequence of GAstV-JSXZ was determined using the next-generation sequencing technique. The complete genome of GAstV-JSXZ was 7299-nt-long. Interestingly, the phylogenetic analysis revealed that Chinese GAstV-1 has formed two distinct subgroups based on the ORF 2 genomes, designated GAstV-1 1a and GAstV-1 1b. The GAstV-JSXZ shared the highest identity with GAstV-1 1a strain FLX and TZ03 in nucleotides (ORF1a: 98.3-98.4%; ORF1b: 92.3-99.1%; ORF2: 95.8-98.8%) and amino acid sequences (ORF1a: 99.4-99.5%; ORF1b: 98.2-98.8%; ORF2: 97.0-99.4%). To evaluate the pathogenicity of GAstV-1, 1-day-old goslings were inoculated with the virus by oral and subcutaneous injection routes, respectively. The results revealed that the virus causes extensive pathological organ damage, especially in the kidney, liver, and thymus. Virus-specific genomic RNA could be detected in the cloacal swabs and tissues of infected goslings throughout the experiment. The viral copy numbers examined in the kidney and intestine were the highest, followed by the liver and spleen. These results are likely to provide a new understanding of the pathogenicity of GAstV-1 in geese.
Assuntos
Infecções por Astroviridae , Gansos , Genoma Viral , Genótipo , Filogenia , Doenças das Aves Domésticas , Animais , Gansos/virologia , China , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Doenças das Aves Domésticas/virologia , Astroviridae/genética , Astroviridae/isolamento & purificação , Astroviridae/classificação , Astroviridae/patogenicidade , Avastrovirus/genética , Avastrovirus/isolamento & purificação , Avastrovirus/classificação , Avastrovirus/patogenicidade , Virulência , Sequenciamento de Nucleotídeos em Larga EscalaRESUMO
Goose astrovirus genotype 2 (GAstV-2) mainly causes gout in goslings; therefore, it is a major pathogen threatening to goose flocks. However, the mechanisms underlying host-GAstV-2 interactions remain unclear because host cells suitable for GAstV-2 replication have been unavailable. We previously noted that GAstV-2 is primarily located in goose renal epithelial cells, where it causes kidney damage. Therefore, here, we derived goose primary renal tubular epithelial (RTE) cells (GRTE cells) from the kidneys of goose embryos after collagenase I digestion. After culture in Dulbecco's modified Eagle medium/Nutrient mixture F-12 with 10% fetal bovine serum (FBS), the isolated cells had polygonal with roadstone-like morphology; they were identified to be epithelial cells based on the presence of cytokeratin 18 expression detected through immunofluorescence assay (IFA). GAstV-2 infection in GRTE cells led to no obvious cytopathic effects; the maximum amounts of infectious virions were observed 48 h post infection through IFA and quantitative PCR. Next, RNA-seq was performed to identify and map post-GAstV-2 infection differentially expressed genes. The downregulated pathways were mainly related to metabolism, including tryptophan metabolism, drug metabolism by cytochrome P450, xenobiotic metabolism by cytochrome P450, retinol metabolism, butanoate metabolism, starch and sucrose metabolism, ascorbate and aldarate metabolism, and drug metabolism by other enzymes and peroxisome. In contrast, the upregulated pathways were mostly related to the host cell defense and proliferation, including extracellular matrix-receptor interaction, complement and coagulation cascades, phagosome, PI3K-Akt signaling pathway, human T-lymphotropic virus 1 infection, lysosome, and tumor necrosis factor signaling pathway. In conclusion, we developed a GRTE cell line for GAstV-2 replication and analyzed the potential host-GAstV-2 interactions through RNA-seq; our results may aid in further investigating the pathogenic mechanisms underlying GAstV-2 infection and provide strategies for its prevention and control.
Assuntos
Infecções por Astroviridae , Células Epiteliais , Gansos , Genótipo , Doenças das Aves Domésticas , Animais , Gansos/virologia , Células Epiteliais/virologia , Doenças das Aves Domésticas/virologia , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Análise de Sequência de RNA/veterinária , Túbulos Renais/virologia , Túbulos Renais/citologia , Avastrovirus/fisiologia , Avastrovirus/genética , Células CultivadasRESUMO
Goose astrovirus (GAstV) is a newly identified viral pathogen threatening waterfowl, exhibiting a high prevalence across various regions in China. Notably, the Guanghan District of Deyang City, situated in Sichuan Province, has faced a outbreak of GAstV, resulting in significant mortality among goslings due to the induction of gout-like symptoms. In our research, we successfully isolated a GAstV strain known as GAstV SCG3. This strain exhibits efficient replication capabilities, proving virulent in goslings and goose embryos. Our study delved into the characteristics of GAstV SCG3 both in vitro and in vivo. Additionally, we examined tissue phagocytosis and the distribution of GAstV SCG3 in deceased goslings using H&E staining and IHC techniques. According to the classification established by the ICTV, GAstV SCG3 falls under the category of GAstV genotype-2. Notably, it demonstrates the highest homology with the published AHAU5 sequences, reaching an impressive 98%. Furthermore, our findings revealed that GAstV SCG3 exhibits efficient proliferation exclusively in goose embryos and in LMH cells, while not manifesting in seven other types of avian and mammalian cells. Significantly, the mortality of GAstV on goslings and goose embryos are 93.1 and 80%, respectively. Moreover, the viral load in the livers of infected goslings surpasses that in the kidneys when compared with the attenuated strain GAstV SCG2. The mortality of GAstV is usually between 20% and 50%, our study marks the first report of a virulent GAstV strain with such a high mortality.
Assuntos
Infecções por Astroviridae , Avastrovirus , Gansos , Genótipo , Doenças das Aves Domésticas , Animais , Gansos/virologia , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/mortalidade , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Virulência , Avastrovirus/genética , Avastrovirus/fisiologia , Avastrovirus/patogenicidade , China , FilogeniaRESUMO
Goose astrovirus (GAstV)-2, a novel pathogen identified in 2018, mainly causes visceral gout in goslings, leading to approximately 50% mortality. At present, no commercial veterinary products are available to prevent and treat the disease. Our previous studies showed that nitric oxide (NO) and inducible NO synthase (iNOS) were markedly higher in the kidney and spleen of goslings infected with GAstV-2, but their effects during GAstV-2 infection remain unclear. In the present study, goslings were intraperitoneally injected with aminoguanidine (AG)-an iNOS inhibitor-to examine the role of NO during GAstV-2 infection. AG significantly decreased the serum NO concentration and iNOS mRNA expression in the kidney. Moreover, AG reduced the mortality, serum uric acid and creatinine content, and urate deposition in visceral organs and joints. Histopathological analysis demonstrated that AG reduced renal tubular cell necrosis, inflammatory cell infiltration, glycogen deposition in glomerular mesangium, and interstitial fibrosis, suggesting alleviation of kidney lesions. Furthermore, AG decreased the expression of renal injury markers such as KIM-1 and desmin; inflammatory cytokine-related genes such as IL-1ß, IL-8, and MMP-9; and autophagy-related genes and proteins such as LC3II, ATG5, and Beclin1. However, quantitative real-time PCR and immunohistochemistry showed that treatment with AG did not affect the kidney and liver viral load. These findings suggest that AG decreases the mortality rate and kidney lesions in goslings infected with GAstV-2 through mechanisms associated with autophagy and inhibition of inflammatory cytokine production in the kidney but not with GAstV-2 replication.
Assuntos
Infecções por Astroviridae , Astroviridae , Avastrovirus , Gota , Guanidinas , Animais , Gansos , Ácido Úrico , Galinhas , Astroviridae/genética , Gota/tratamento farmacológico , Gota/veterinária , Infecções por Astroviridae/tratamento farmacológico , Infecções por Astroviridae/veterinária , Rim/patologia , Citocinas , Avastrovirus/genéticaRESUMO
BACKGROUND: Enteric viruses are among the most prominent etiological agents of Runting-Stunting Syndrome (RSS). The Avian Nephritis Virus (ANV) is an astrovirus associated with enteric diseases in poultry, whose early diagnosis is essential for maintaining a good poultry breeding environment. ANV is an RNA virus that rapidly mutates, except for some conserved regions such as ORF1b. Therefore, the approach of a diagnostic method based on fast-RT-qPCR using SYBR® Green that focuses on the amplification of a fragment of ORF1b is presented as a feasible alternative for the diagnosis of this viral agent. In this study, the proposed assay showed a standard curve with an efficiency of 103.8% and a LoD and LoQ of 1 gene viral copies. The assay was specific to amplify the ORF 1b gene, and no amplification was shown from other viral genomes or in the negative controls. 200 enteric (feces) samples from chickens (broilers) and laying hens with signs of RSS from Ecuadorian poultry flocks were examined to validate the proposed method. RESULTS: Using our method, 164 positive results were obtained out of the total number of samples run, while the presence of viral RNA was detected in samples collected from one day to 44 weeks old in both avian lines. CONCLUSIONS: Our study presents a novel, rapid, robust, and sensitive molecular assay capable of detecting and quantifying even low copy numbers of the ANV in commercial birds, therefore introducing a handy tool in the early diagnosis of ANV in enteric disease outbreaks in poultry.
Assuntos
Infecções por Astroviridae , Avastrovirus , Doenças das Aves Domésticas , Vírus de RNA , Animais , Feminino , Galinhas , Avastrovirus/genética , Infecções por Astroviridae/diagnóstico , Infecções por Astroviridae/veterinária , RNA Viral/genética , RNA Viral/análise , Aves Domésticas , Vírus de RNA/genéticaRESUMO
RESEARCH HIGHLIGHTS: Urate tophi were found in the kidneys, liver, spleen and lungs.IFA confirmed the co-expression of GoAstV-I and II antigens in the same kidney.
Assuntos
Infecções por Astroviridae , Astroviridae , Avastrovirus , Coinfecção , Gota , Doenças das Aves Domésticas , Animais , Gansos , Infecções por Astroviridae/veterinária , Coinfecção/veterinária , Astroviridae/genética , Gota/veterinária , Avastrovirus/genética , ChinaRESUMO
It is well-established that the genetic diversity, regional prevalence, and broad host range of astroviruses significantly impact the poultry industry. In July 2022, a small-scale commercial broiler farm in China reported cases of growth retardation and a 3% mortality rate. From chickens displaying proventriculitis and pancreatitis, three chicken astroviruses (CAstV) isolates were obtained and named SDAU2022-1-3. Complete genomic sequencing and analysis revealed the unique characteristics of these isolates from known CAstV strains in ORF1a, ORF1b, and ORF2 genes, characterized by an unusually high variability. Analysis of amino acid mutations in ORF1a, ORF1b, and ORF2 indicated that the accumulation of these mutations played a pivotal role in the emergence of the variant strain. Inoculation experiments demonstrated that affected chickens exhibited liver and kidney enlargement, localized proventricular hemorrhage, and a dark reddish-brown appearance in about two-thirds of the pancreas. Histopathological examination unveiled hepatic lymphocytic infiltration, renal tubular epithelial cell swelling, along with lymphocytic proventriculitis and pancreatitis. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis indicated viremia and viral shedding at 3 days post-infection (dpi). The proventriculus displayed the highest viral loads, followed by the liver, kidney, duodenum, and pancreas. Liver parameters (AST and ALT) and kidney parameters (UA and UN) demonstrated mild damage consistent with earlier findings. While the possibility of new mutations in the ORF2 gene of CAstV causing proventriculitis and pancreatitis warrants further investigation, these findings deepen our comprehension of CAstV's pathogenicity in chickens. Additionally, they serve as valuable references for subsequent research endeavors.
Assuntos
Infecções por Astroviridae , Avastrovirus , Pancreatite , Doenças das Aves Domésticas , Animais , Avastrovirus/genética , Galinhas , Virulência , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/epidemiologia , Pancreatite/veterinária , FilogeniaRESUMO
miRNAs represent ubiquitous regulators of gene expression and play an important and pivotal regulatory role in viral disease pathogenesis and virus-host interactions. Although previous studies have provided basic data for understanding the role of miRNAs in the molecular mechanisms of viral infection in birds, the role of miRNAs in the regulation of host responses to chicken astrovirus (CAstV) infection in chickens is not yet understood. In our study, we applied next-generation sequencing to profile miRNA expression in CAstV-infected chickens and to decipher miRNA-targeted specific signaling pathways engaged in potentially vital virus-infection biological processes. Among the 1354 detected miRNAs, we identified 58 mature miRNAs that were significantly differentially expressed in infected birds. Target prediction resulted in 4741 target genes. GO and KEGG pathway enrichment analyses showed that the target genes were mainly involved in the regulation of cellular processes and immune responses.
Assuntos
Avastrovirus , MicroRNAs , Animais , MicroRNAs/genética , MicroRNAs/metabolismo , Galinhas/metabolismo , Avastrovirus/genética , Avastrovirus/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Interações entre Hospedeiro e MicrorganismosRESUMO
Gosling gout has posed a serious threat to the development of the China's goose industry since the outbreak in mainland China in 2016; goose astrovirus (GAstV) was identified as the culprit pathogen. Two genotypes of this virus have been identified: GAstV-1 and GAstV-2, of which GAstV-2 is the main epidemic strain. Our current understanding of the pathogenic mechanisms of GAstV-2 remains limited. To assess pathogenicity, 1-day-old goslings were inoculated with the GAstV-2 YC20 strain via the subcutaneous, intranasal, and oral infection routes. All the goslings showed typical gout symptoms, with those in the oral infection group exhibiting earlier and more severe clinical symptoms, the highest mortality rate, and greatest weight loss. The blood biochemical indicators, viral loads in cloacal swabs and all representative tissues, and serum antibody titers of all infection groups increased significantly, and no significant differences in these parameters were observed among the three infection groups. Histopathological studies showed that the livers, kidneys, and spleens were the main damaged organs, and the pathological changes in the oral group were more severe than those in the other groups. Further analysis revealed that hepatic sinuses narrowed or became occluded as early as 1 day post-inoculation; urate deposition occurred in the renal tubules at 2 days post-inoculation (dpi), followed by necrosis of renal tubular epithelial cells; and lymphocytic infiltration appeared in the splenic tissue at 5 dpi. These results further our understanding of the pathogenic mechanisms of GAstV-2 and provide a reference for future studies.
Assuntos
Infecções por Astroviridae , Avastrovirus , Gota , Doenças das Aves Domésticas , Animais , Gansos , Infecções por Astroviridae/veterinária , Virulência , Avastrovirus/genética , Gota/veterinária , FilogeniaRESUMO
Goose astroviruses (GoAstVs) are causative agents that account for fatal infection of goslings characterized by visceral urate deposition, resulting in severe economic losses in major goose-producing regions in China since 2017. In this study, we sought to unravel the intrinsic properties associated with adaptation and evolution in the host environment of GoAstVs. Consistent results from phylogenetic analysis and correspondence analysis performed on the codon usage patterns (CUPs) reveal 2 clusters of GoAstVs, namely, GoAstV-1 and GoAstV-2. However, multiple similar compositional characteristics were found, despite the high divergence between GoAstV-1 and GoAstV-2. Studies on the base composition of GoAstVs reveal an A/U bias, indicating a compositional constraint, while natural selection prevailed in determining the CUPs in the virus genome based on our neutrality plot analysis, reflecting high adaptive pressure to fit the host environment. Codon adaptation index (CAI) analysis revealed a higher degree of fitness to the CUPs of the corresponding host for GoAstVs than avian influenza virus and betacoronaviruses, which may be a favorable factor contributing to the high pathogenicity and wide distribution of GoAstVs in goslings. In addition, GoAstVs were less adapted to ducks and chickens, with significantly lower CAI values than to geese, which may be a reason for the different prevalence of GoAstVs among these species. Extensive investigations on dinucleotide distribution revealed a significant suppression of the CpG and UpA motifs in the virus genome, which may facilitate adaptation to the host's innate immune system by evading surveillance. In addition, our study reported the trends of increasing fitness to the host's microenvironment for GoAstVs through increasing adaptation to host CUPs and ongoing reduction of CpG motifs in the virus genome. The present analysis deepens our understanding of the basic biology, pathogenesis, adaptation and evolutionary pattern of GoAstVs, and contributes to the development of novel antiviral strategies.
Assuntos
Avastrovirus , Gansos , Animais , Gansos/genética , Composição de Bases , Filogenia , Galinhas/genética , Códon , Avastrovirus/genéticaRESUMO
The emergence of Goose astrovirus (GoAstV) has led to the gout in geese. This study aimed to isolate and identify the GoAstV from diseased goslings in Sichuan Province, China, followed by performing whole genome phylogenetic analysis of the isolate. The GoAstV was successfully isolated by inoculating the diseased gosling liver and kidney homogenate into the 11-day-old goose embryo allantoic cavity for 3 passages, and the isolate was named as GoAstV-C2 strain. The virus particles were spherical, without capsule, and the size was about 28 nm under transmission electronic microscope. The complete genome length of GoAstV-C2 was 7.035 nt, and the whole genome sequence phylogenetic analysis revealed that it belongs to the GoAstV genotype II (GoAstV-II) subgenotype IIc. The isolated GoAstV-C2 strain was able to be stably passaged in the goose embryo and uric acid sedimentation was observed. The complete genome bioinformation of GoAstV-C2 determined the evolutionary characteristics of the GoAstV isolated from Sichuan, China. This finding lays a foundation for the development of preventive measures, effective vaccines, and therapeutic drugs.
Assuntos
Infecções por Astroviridae , Avastrovirus , Doenças das Aves Domésticas , Animais , Gansos , Infecções por Astroviridae/epidemiologia , Infecções por Astroviridae/veterinária , Filogenia , Doenças das Aves Domésticas/epidemiologia , Galinhas , Avastrovirus/genética , Genótipo , ChinaRESUMO
The enteric chicken astrovirus (CAstV) and avian nephritis virus (ANV) are the type species of the genus Avastrovirus (AAstV; Astroviridae family), capable of causing considerable production losses in poultry. Using next-generation sequencing of a cloacal swab from a backyard chicken in Tanzania, we assembled genome sequences of ANV and CAstV (6918 nt and 7318 nt in length, respectively, excluding poly(A) tails, which have a typical AAstV genome architecture (5'-UTR-ORF1a-ORF1b-ORF2-'3-UTR). They are most similar to strains ck/ANV/BR/RS/6R/15 (82.72%) and ck/CAstV/PL/G059/14 (82.23%), respectively. Phylogenetic and sequence analyses of the genomes and the three open reading frames (ORFs) grouped the Tanzanian ANV and CAstV strains with Eurasian ANV-5 and CAstV-Aii viruses, respectively. Compared to other AAstVs, the Tanzanian strains have numerous amino acid variations (substitutions, insertions and deletions) in the spike region of the capsid protein. Furthermore, CAstV-A has a 4018 nt recombinant fragment in the ORF1a/1b genomic region, predicted to be from Eurasian CAstV-Bi and Bvi parental strains. These data should inform future epidemiological studies and options for AAstV diagnostics and vaccines.
Assuntos
Infecções por Astroviridae , Astroviridae , Avastrovirus , Doenças das Aves Domésticas , Animais , Avastrovirus/genética , Tanzânia/epidemiologia , Filogenia , Infecções por Astroviridae/epidemiologia , Infecções por Astroviridae/veterinária , Astroviridae/genética , Galinhas , Doenças das Aves Domésticas/epidemiologiaRESUMO
Novel goose astrovirus (NGAstV) is a member of the genus Avain Avastrovirus (AAstV) and the family Astroviridae. NGAstV-associated gout disease has caused huge economic losses to the goose industry worldwide. Since early 2020, NGAstV infections characterized by articular and visceral gout emerged continuously in China. Herein, we isolated a GAstV strain from goslings with fatal gout disease and sequenced its complete genome nucleotide sequence. Then we conducted systematic genetic diversity and evolutionary analysis. The results demonstrated that two genotypic species of GAstV (GAstV-I and GAstV-II) were circulating in China, and GAstV-II sub-genotype IId had become the dominant one. Multiple alignments of amino acid sequences of GAstV capsid protein revealed that several characteristic mutations (E456D, A464N, and L540Q) in GAstV-II d strains, as well as additional residues in the newly identified isolate which varied over time. These findings enrich the understanding of the genetic diversity and evolution of GAstV and may facilitate the development of effective preventive strategies.
Assuntos
Artrite Gotosa , Avastrovirus , Gota , Animais , Gansos , Avastrovirus/genética , Genômica , Gota/genética , Gota/veterinária , ChinaRESUMO
Goose astrovirus genotype 2 (GAstV-2) is the causative agent causing severe visceral gout and joint gout in goslings, with mortality rates of affected flocks up to 50%. To date, continuous GAstV-2 outbreaks still pose a great threat to goose industry in China. Although most researches on GAstV-2 have focused on its pathogenicity to geese and ducks, limited studies have been performed on chickens. Herein, we inoculated 1-day-old specific pathogen-free (SPF) White Leghorn line chickens with 0.6 mL of GAstV-2 culture supernatant (TCID50 10-5.14/0.1 mL) via orally, subcutaneously and intramuscularly, and then assessed the pathogenicity. The results revealed that the infected chickens presented depression, anorexia, diarrhea, and weight loss. The infected chickens also suffered from extensive organ damage and had histopathological changes in the heart, liver, spleen, kidney, and thymuses. The infected chickens also had high viral load in tissues and shed virus after the challenge. Overall, our research demonstrates that GAstV-2 can infect chickens and adversely affect the productivity of animals. And the viruses shed by infected chickens can pose a potential risk to the same or other domestic landfowls.
Assuntos
Infecções por Astroviridae , Avastrovirus , Gota , Doenças das Aves Domésticas , Animais , Gansos , Galinhas , Infecções por Astroviridae/veterinária , Virulência/genética , Avastrovirus/genética , Gota/veterinária , Genótipo , China/epidemiologia , FilogeniaRESUMO
The epidemic of goose astrovirus (GoAstV) caused huge losses to the poultry industry. Epidemiological studies in China revealed 2 circulating genotypes of GoAstV, but there is a lack of differential diagnosis tools. By analyzing all published genomes of GoAstV, this study designed specific PCR primers and Taqman probes to recognize different genotypes of GoAstV. After optimization and verification, this study developed a Taqman-based real-time quantitative PCR method that is capable of differential diagnosis. The established qPCR exhibited detection limitations of 100 copies/µL or 10 copies/µL, respectively, for GoAstV genotype 1 and genotype 2, and showed no false positive for other common avian viruses. This method was then used to analyze 72 samples collected from different regions in Jiangxi, and the results were verified by genome sequencing and phylogenetic analysis. These results revealed a complex coinfection of GoAstV different genotypes in China, highlighting the importance of long-term focus on the prevalence and genome evolution of GoAstV.
Assuntos
Avastrovirus , Gansos , Animais , Gansos/genética , Filogenia , Galinhas/genética , Avastrovirus/genética , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Reação em Cadeia da Polimerase em Tempo Real/métodos , Genótipo , Sensibilidade e EspecificidadeRESUMO
While blocking inflammation is an effective way to ease the symptoms of gout disease in humans, the treatment and prevention of gout in goslings infected with goose astrovirus (GAstV), a recently emergent condition, remain unclear. In this study, we investigated the reprogramming of the host genes as a result of GAstV infection by combining analysis of the global transcriptome and metabolic network pathways in the kidneys of goslings infected with GAstV. We showed that as GAstV replication increased in vivo, the regulation of key enzymes in the host metabolism progressively increased, flowing metabolites into the purine/pyrimidine biosynthesis pathways. Furthermore, we found that GAstV: 1) inhibits the host oxidation-reduction response by inhibiting the expression of the catalase gene; 2) activates the Toll-like receptor 2 pathway to enhance the immune inflammatory response; and 3) activates the key enzyme in lactic acid synthesis to produce lactate accumulation which inhibits the host's antiviral response, so as to facilitate the replication of the virus itself. This study provided the first insight into the overall metabolic requirements of GAstV for replication in vivo by combining transcriptome with metabolic network pathway information.
Assuntos
Infecções por Astroviridae , Avastrovirus , Gota , Doenças das Aves Domésticas , Humanos , Animais , Gansos , Transcriptoma , Filogenia , Avastrovirus/genética , Infecções por Astroviridae/veterinária , Gota/veterináriaRESUMO
Avian nephritis virus (ANV) infection is associated with diarrhea, uricosis, stunting, tubulonephrosis, interstitial nephritis, and mortality of chicken flocks, leading to economic losses in the poultry industry. In this study, an ANV strain designated as HNU-ANV-ML-2020 was identified in tissue samples collected from chickens with severe enteritis on a poultry farm in Hunan province, China, and analyzed. The genome of HNU-ANV-ML-2020 is 6943 nucleotides in length. It showed the highest sequence identity (88.1%) to ANV strain CHN/GXJL815/2017 (MN732559) from Guangxi province, China, while it showed less than 86% identity to other astrovirus (AstV) genome sequences available in the GenBank database. The capsid protein of this virus showed the highest sequence identity to ANV strains HQ330482 and HQ330498 from the UK (81.2% and 81.06%, respectively), while it showed only 73.9% identity to MN732559 and less than 80% identity to the capsid proteins of other AstVs available in GenBank. Further phylogenetic analysis demonstrated that HNU-ANV-ML-2020 belongs to group 4, together with ANV strains identified in Australia, Brazil, the UK, and the Netherlands. Furthermore, ANV strains identified in chickens in China were found to be separated into four distinct groups/genotypes, indicating substantial genetic divergence and a complex circulation pattern in China. The virus characterized in the present study is a novel ANV variant identified for the first time in Hunan province, China.