RESUMO
A novel goose astrovirus (GAstV) has broken out across China in recent years, causing widespread damage to the poultry industry. In goslings infected with GAstV, the leading cause of death is visceral gout. However, our understanding of the mechanism of gout formation in GAstV infection is largely inadequate. The aim of this study was to examine the pathogenicity of a GAstV strain and explore the molecular mechanisms of visceral gout caused by viral infection in goslings. The virulent GAstV strain HR2105/1 was effectively isolated from the visceral tissue of goslings in gout-affected areas. The whole genome of the HR2105/1 strain was sequenced and analyzed. Subsequently, we established a gosling gout models with experimental GAstV infection. Finally, we conducted a study on the mechanism of GAstV induced acute kidney injury. Phylogenetic analysis of the complete genome sequence showed that it was closely related to the strain circulating in China since 2016, and it was grouped within the GAstV-1 cluster. The clinical signs were reproduced by experimental infection of healthy goslings with the isolated strain and were found to be similar to those reported in clinical cases. Moreover, the virus exhibits strong renal tropism. Infection with the GAstV strain HR2105/1 was found to cause acute kidney injury, as evidenced by increased levels of uric acid and creatinine as well as severe pathological damage. Mechanistic experiments with Masson and Picrosirius Red staining revealed fibrosis in renal tissues after GAstV infection. Furthermore, TUNEL staining revealed that GAstV infection triggered renal cell apoptosis. Additionally, RT-qPCR revealed that GAstV infection caused an excessive inflammatory response by upregulating the expression of IL-1ß, IL-6, IL-10, TGF-ß, and iNOS in renal tissues. Overall, our findings demonstrate that GAstV infection causes renal damage by inducing renal cell apoptosis, fibrosis, and excessive inflammatory response, which subsequently leads to hyperuricemia and lethal visceral gout formation. This is the first systematic study on the etiology of lethal gout in goslings caused by GAstV infection, and we believe that the findings can guide vaccine development and therapeutic targets for GAstV-associated renal diseases.
Assuntos
Injúria Renal Aguda , Infecções por Astroviridae , Gansos , Gota , Filogenia , Doenças das Aves Domésticas , Animais , Gansos/virologia , Gota/virologia , Gota/patologia , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Infecções por Astroviridae/patologia , Injúria Renal Aguda/virologia , Injúria Renal Aguda/patologia , China , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/patologia , Rim/patologia , Rim/virologia , Genoma Viral , Avastrovirus/genética , Avastrovirus/isolamento & purificação , Avastrovirus/patogenicidade , Sequenciamento Completo do Genoma , Modelos Animais de Doenças , Astroviridae/genética , Astroviridae/isolamento & purificação , População do Leste AsiáticoRESUMO
Diarrhea is one of the major public health issues worldwide. Although the infections of individual enteric virus have been extensively studied, elucidation of the coinfection involving multiple viruses is still limited. In this study, we identified the coinfection of human adenovirus (HAdV) and human astrovirus (HAstV) in a child with acute gastroenteritis, analyzed their genotypes and molecular evolution characteristics. The sample was collected and identified using RT-PCR and subjected to whole-genome sequencing on the NovaSeq (Illumina) platform. Obtained sequences were assembled into the complete genome of HAdV and the ORF1 of HAstV. We conducted phylogenetic analysis using IQ-TREE software and conducted recombination analysis with the Recombination Detection Program. The sequenced HAdV was confirmed to be genotype 41, and was genetically close to some European strains. Phylogenetic analysis revealed that the HAstV was genetically close to both HAstV-2 and HAstV-4 and was different from the genotype prevalent in Shenzhen before. The recombination analysis confirmed that the sequenced HAstV strain is a recombinant of HAstV-2 and HAstV-4. Our analysis has shown that the strains in this coinfection are both uncommon variants in this geographical region, instead of dominant subtypes that have prevailed for years. This study presents a coinfection of HAdV and HAstV and conducts an evolutionary analysis on involved viruses, which reveals the genetic diversity of epidemic strains in Southern China and offers valuable insights into vaccine and medical research.
Assuntos
Infecções por Adenovirus Humanos , Adenovírus Humanos , Infecções por Astroviridae , Coinfecção , Gastroenterite , Genótipo , Mamastrovirus , Filogenia , Recombinação Genética , Humanos , Coinfecção/virologia , Coinfecção/epidemiologia , Gastroenterite/virologia , Mamastrovirus/genética , Mamastrovirus/isolamento & purificação , Mamastrovirus/classificação , China/epidemiologia , Infecções por Astroviridae/virologia , Infecções por Astroviridae/epidemiologia , Adenovírus Humanos/genética , Adenovírus Humanos/classificação , Adenovírus Humanos/isolamento & purificação , Infecções por Adenovirus Humanos/virologia , Infecções por Adenovirus Humanos/epidemiologia , Genoma Viral/genética , Sequenciamento Completo do Genoma , Masculino , Análise de Sequência de DNA , Pré-Escolar , Evolução MolecularRESUMO
Recently, neurological diseases associated with astroviruses (AstVs) have been reported in pigs, ruminants, minks, and humans. In 2017, neuro-invasive porcine astrovirus (Ni-PAstV) 3 was detected in the central nervous system (CNS) of pigs with encephalomyelitis in Hungary and the USA. In the process of diagnosing domestic pigs exhibiting neurological signs, histopathologic lesions of non-suppurative encephalomyelitis with meningitis, neuronal vacuolation, and gliosis were detected, and PAstV was identified using reverse transcriptase PCR in CNS samples of four pigs in three farms from August to September in 2020, South Korea. Subsequently, the ORF2 region was successfully acquired from three brain samples, facilitating subsequent analysis. Four genotypes of PAstV (PAstV1, 3, 4, and 5) were detected, and coinfection of PAstV with multiple genotypes was observed in brain samples. This is the first study to report Ni-PAstV infection in pigs in South Korea.
Assuntos
Infecções por Astroviridae , Encéfalo , Genótipo , Filogenia , Doenças dos Suínos , Animais , Suínos , Doenças dos Suínos/virologia , Doenças dos Suínos/patologia , República da Coreia/epidemiologia , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Encéfalo/virologia , Encéfalo/patologia , Mamastrovirus/genética , Mamastrovirus/isolamento & purificação , Mamastrovirus/classificaçãoRESUMO
Bats (order: Chiroptera) are known to host a diverse range of viruses, some of which present a human public health risk. Thorough viral surveillance is therefore essential to predict and potentially mitigate zoonotic spillover. Astroviruses (family: Astroviridae) are an understudied group of viruses with a growing amount of indirect evidence for zoonotic transfer. Astroviruses have been detected in bats with significant prevalence and diversity, suggesting that bats may act as important astrovirus hosts. Most astrovirus surveillance in wild bat hosts has, to date, been restricted to single-gene PCR detection and concomitant Sanger sequencing; additionally, many bat species and many geographic regions have not yet been surveyed for astroviruses at all. Here, we use metagenomic Next Generation Sequencing (mNGS) to detect astroviruses in three species of Madagascar fruit bats, Eidolon dupreanum, Pteropus rufus, and Rousettus madagascariensis. We detect numerous partial sequences from all three species and one near-full length astrovirus sequence from Rousettus madagascariensis, which we use to characterize the evolutionary history of astroviruses both within bats and the broader mammalian clade, Mamastrovirus. Taken together, applications of mNGS implicate bats as important astrovirus hosts and demonstrate novel patterns of bat astrovirus evolutionary history, particularly in the Southwest Indian Ocean region.
Assuntos
Infecções por Astroviridae , Astroviridae , Quirópteros , Metagenômica , Filogenia , Animais , Quirópteros/virologia , Astroviridae/genética , Astroviridae/isolamento & purificação , Astroviridae/classificação , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Infecções por Astroviridae/epidemiologia , Sequenciamento de Nucleotídeos em Larga Escala , Madagáscar , Genoma Viral/genética , Análise de Sequência de DNARESUMO
Introduction: Goose astrovirus (GAstV) is a newly emerging pathogen that is currently widespread among geese, causing visceral gout and leading to substantial gosling mortalities, posing a severe threat to the waterfowl industry. GAstV II is the predominant epidemic strain, characterized by its high morbidity and mortality rate. Consequently, there is an urgent necessity to develop an effective diagnostic approach to control the dissemination of GAstV II, particularly in clinical farms with limited laboratory resources. Methods: In this study, a novel multi-enzyme isothermal rapid amplification (MIRA) and lateral flow dipstick (LFD) combined assay was developed. Different primers designed specific targeting a highly conserved region within the viral RdRp gene for the detection of GAstV II. Primers optimized and MIRA-LFD assay analyzed its performance regarding limits of detection, specificity, and efficiency of detection. Results: The developed MIRA amplification is conducted at a constant temperature and accomplished within 10 minutes. Subsequent naked-eye observation of the LFD strips merely takes 5 minutes. The established MIRA-LFD method exhibits high specificity, with no cross-reaction with other pathogens and attains a detection sensitivity of 1 copy/µl, which is consistent with the reverse transcription quantitative PCR (RT-qPCR) assay. Further evaluation with clinical samples indicates that the accuracy of this MIRA-LFD method correlates well with RT-qPCR for the detection of GAstV II. Conclusion: In summary, the convenience, sensitivity, and rapidity of this newly developed detection method offer a significant advantage for on-site diagnosis of GAstV II.
Assuntos
Infecções por Astroviridae , Gansos , Técnicas de Diagnóstico Molecular , Técnicas de Amplificação de Ácido Nucleico , Doenças das Aves Domésticas , Sensibilidade e Especificidade , Animais , Infecções por Astroviridae/diagnóstico , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Gansos/virologia , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Diagnóstico Molecular/métodos , Doenças das Aves Domésticas/diagnóstico , Doenças das Aves Domésticas/virologia , Avastrovirus/genética , Avastrovirus/isolamento & purificação , Primers do DNA/genética , RNA Viral/genéticaRESUMO
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.
Assuntos
Infecções por Astroviridae , Avastrovirus , Galinhas , Patos , Hepatite Viral Animal , Doenças das Aves Domésticas , Animais , Patos/virologia , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/epidemiologia , China/epidemiologia , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/epidemiologia , Infecções por Astroviridae/virologia , Avastrovirus/patogenicidade , Avastrovirus/genética , Avastrovirus/isolamento & purificação , Hepatite Viral Animal/virologia , Hepatite Viral Animal/epidemiologia , Epidemiologia Molecular , Filogenia , Virulência , Masculino , PrevalênciaRESUMO
The fatal gouty disease caused by goose astrovirus genotype 2 (GAstV-2) still seriously endangers the goose industry in China, causing great economic losses. However, research on its infection mechanism has progressed relatively slowly. VP70 is the structural protein of GAstV-2 and is closely related to virus invasion and replication. To better understand the role of VP70 during GAstV-2 infection, we used immunoprecipitation and mass spectrometry to identify host proteins that interact with VP70. Here, we report that cellular vimentin (VIM) is a host binding partner of VP70. Site-directed mutagenesis showed that amino acid residues 399 to 413 of VP70 interacted with VIM. Using reverse genetics, we found that VP70 mutation disrupts the interaction of VP70 with VIM, which is essential for viral replication. Overexpression of VIM significantly promoted GAstV-2 replication, while knockdown of VIM significantly inhibited GAstV-2 replication. Laser confocal microscopy showed that VP70 protein expression induced the rearrangement of VIM, gradually aggregating from the original uniform grid to the side of the nucleus, and aggregated the originally dispersed GAstV-2 RNA in VIM. This rearrangement was associated with increased VIM phosphorylation caused by GAstV-2. Meanwhile, blocking VIM rearrangement with acrylamide substantially inhibited viral replication. These results indicate that VIM interacts with VP70 and positively regulates GAstV-2 replication, and VIM-VP70 interaction and an intact VIM network are needed for GAstV-2 replication. This study provides a theoretical basis and novel perspective for the further characterization of the pathogenic mechanism of GAstV-2-induced gouty disease in goslings.
Assuntos
Avastrovirus , Gansos , Doenças das Aves Domésticas , Vimentina , Replicação Viral , Animais , Gansos/virologia , Doenças das Aves Domésticas/virologia , Vimentina/metabolismo , Vimentina/genética , Avastrovirus/genética , Avastrovirus/fisiologia , Avastrovirus/metabolismo , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Genótipo , Proteínas Aviárias/metabolismo , Proteínas Aviárias/genéticaRESUMO
Goose astrovirus (GAstV) has been widespread in China since 2016, causing significant growth inhibition and gout symptoms in goslings and leading to substantial economic losses in the goose industry. To better understand the epidemiological characteristics of GAstV in Guangdong Province, 682 samples were collected from geese with suspected GAstV infection across different regions of Guangdong Province from January 2022 to January 2024. Virus isolation, identification, and genetic evolution analysis were performed. The results showed that all samples were GAstV positive, with 52.64% co-infected with GAstV-1 and GAstV-2, and 42.38% positive for GAstV-2 alone, indicating that GAstV-2 remains the most prevalent subtype. Additionally, three GAstV isolates were identified using molecular detection, immunofluorescence, and transmission electron microscopy on LMH cells or goose embryos. Compared with GDYJ2304 and other reported GAstV-2 strains, the ORF2 region of the GDYJ2210 isolates lacked 3 bases, and the replication ability of GDYJ2210 was significantly higher than that of GDYJ2304. Whole genome sequence alignment and genetic evolution analysis revealed that the GDFS2209 isolate was located in the GAstV-1 branch, with a sequence similarity of 89.70 to 99.00% to GAstV-1 reference strains. The GDYJ2210 and GDYJ2304 isolates were located in the GAstV-2 branch, showing a sequence similarity of 96.80 to 98.90% to GAstV-2 reference strains. These results demonstrated that the GAstV isolates were highly similar to each other despite being prevalent in 5 different regions of Guangdong Province. These findings enhance the understanding of the genetic diversity and evolution of GAstV and may facilitate the development of effective preventive strategies.
Assuntos
Infecções por Astroviridae , Avastrovirus , Gansos , Filogenia , Doenças das Aves Domésticas , Animais , Gansos/virologia , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Infecções por Astroviridae/epidemiologia , China/epidemiologia , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/epidemiologia , Avastrovirus/genética , Avastrovirus/isolamento & purificação , Avastrovirus/fisiologia , Gota/veterinária , Gota/virologia , Gota/epidemiologiaRESUMO
Astroviruses are single-stranded, positive-sense RNA viruses capable of infecting humans as well as a wide range of mammalian and avian species, with a length of approximately 6.6-7.7 kb. In this study, 139 goat fecal samples collected from the Guangxi province were used for the RT-PCR detection, and two of these were positive for goat astrovirus, with a positivity rate of 1.44% (2/139). The complete genome sequence of an astrovirus strain and the partial genome sequence of a strain astrovirus, named GX WZ 2023 and GX HC 2023, were amplified and sequenced, and their sequence lengths were 6284 nt and 6213 nt, respectively. Among them, the capsid protein of goat astrovirus GX HC 2023 showed the highest amino acid identity of 95.9% with ovine astrovirus GX, which belonged to the MAstV-2 genotype. However, the closest relative of the GX WZ 2023 strain was found to be the caprine astrovirus Sichuan, with a nucleotide sequence identity of 76.8%. The ORF1ab nonstructural protein of this strain showed the highest amino acid identities of 89.2 and 95.8% with the ovine astrovirus S5.1 and caprine astrovirus G5.1 strains, respectively. However, its ORF2 capsid protein has 68.4% amino acid identity with the bovine astrovirus (BAstV) 16 2021 CHN strain and only 21.9-64% amino acid identity with all available strains of goat astrovirus. The GX WZ 2023 strain was recombined with the Chinese (BAstV 16 2021 CHN) and Japanese bovine strains (BAstV JPN 2015) in the ORF2 region. Therefore, the goat astrovirus GX WZ 2023 is proposed as a new member of the family goat astroviridae based on the species classification criteria of the International Committee on Taxonomy of Viruses. These findings enhance our understanding of the prevalence and genetic evolution of goat astrovirus and provide a scientific basis for future studies of these viruses in other animals.
Assuntos
Infecções por Astroviridae , Genoma Viral , Genótipo , Doenças das Cabras , Cabras , Mamastrovirus , Filogenia , Animais , Cabras/virologia , China/epidemiologia , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Infecções por Astroviridae/epidemiologia , Doenças das Cabras/virologia , Doenças das Cabras/epidemiologia , Mamastrovirus/genética , Mamastrovirus/classificação , Mamastrovirus/isolamento & purificação , Fezes/virologia , Proteínas do Capsídeo/genética , Recombinação Genética , RNA Viral/genética , Astroviridae/genética , Astroviridae/classificação , Astroviridae/isolamento & purificação , Ovinos , Análise de Sequência de DNARESUMO
Applying a pan-astrovirus (AstV) RT-hemi-nested PCR assay, we report here high detection rates (28.3%, 15/53) of AstVs in the small Indian mongoose (Urva auropunctata) on the Caribbean Island of St. Kitts. Based on deduced amino acid (aa) identities and phylogenetic analysis of long RNA-dependent RNA polymerase (RdRp) sequences (~315 aa, partial RdRp), the AstVs detected in the mongooses (designated as Mon-AstVs) were classified into two distinct groups (deduced aa identities of 66.45-67.30% between the groups). The putative RdRps of the Mon-AstVs shared low deduced aa identities with those of AstVs from other host species (<69%, <54%, and <50% identities with reptilian/amphibian AstVs, avastroviruses, and mamastroviruses, respectively). Phylogenetically, the group-I and group-II Mon-AstVs formed two distinct clusters, near the cluster of reptilian/amphibian AstVs, and were distantly related to avastroviruses and mamastroviruses. Since the mongooses were apparently healthy during sampling, we could not establish if the Mon-AstVs infected the animal or were of dietary origin. Although we could not ascertain the true host of the Mon-AstVs, phylogenetic analysis indicated that these viruses might have originated from lower vertebrates. To our knowledge, this is the first report on the detection and molecular characterization of AstVs in mongooses, highlighting the wide host range and significant genetic diversity within the family Astroviridae.
Assuntos
Infecções por Astroviridae , Astroviridae , Herpestidae , Filogenia , Herpestidae/virologia , Infecções por Astroviridae/virologia , Infecções por Astroviridae/veterinária , Animais , Astroviridae/genética , Astroviridae/isolamento & purificação , Astroviridae/classificação , RNA Polimerase Dependente de RNA/genética , RNA Viral/genéticaRESUMO
An essential aspect of positive-sense RNA virus replication is anchoring the replication complex (RC) to cellular membranes. Positive-sense RNA viruses employ diverse strategies, including co-translational membrane targeting through signal peptides and co-opting cellular membrane trafficking components. Often, N-terminal nonstructural proteins play a crucial role in linking the RC to membranes, facilitating the early association of the replication machinery. Astroviruses utilize a polyprotein strategy to synthesize nonstructural proteins, relying on subsequent processing to form replication-competent complexes. This study provides evidence for the perinuclear ER membrane association of RCs in five distinct human astrovirus strains. Using tagged recombinant classical human astrovirus 1 and neurotropic MLB2 strains, we establish that the N-terminal domain guides the ER membrane association. We identified di-arginine motifs responsible for the perinuclear ER retention and formation of functional RCs through mutational analysis of the N-terminal domain in replicon and reverse genetics systems. In addition, we demonstrate the association of key components of the astrovirus replication complex: double-stranded RNA, RNA-dependent RNA polymerase, protease, and N-terminal protein. Our findings highlight the intricate virus-ER interaction mechanism employed by astroviruses, potentially leading to the development of novel antiviral intervention strategies.
Assuntos
Retículo Endoplasmático , Mamastrovirus , Proteínas não Estruturais Virais , Replicação Viral , Proteínas não Estruturais Virais/metabolismo , Proteínas não Estruturais Virais/genética , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/virologia , Replicação Viral/fisiologia , Humanos , Mamastrovirus/metabolismo , Mamastrovirus/genética , Infecções por Astroviridae/virologia , Infecções por Astroviridae/metabolismo , Membranas Intracelulares/metabolismo , Membranas Intracelulares/virologiaRESUMO
Enteropathies are a serious concern in racing pigeons as they significantly impair performance in races and their training, and viruses are suspected to be one of the main factors. Astroviruses are well-known to be responsible for causing enteric disease in humans and various other animals including birds, although their prevalence and pathogenicity in pigeons is poorly understood. In this study, we investigated 2 groups of young racing pigeons (sick-study group and healthy-control group) to assess the correlation between the number of astrovirus genome copies in cloacal swabs and the occurrence of enteropathy. To determine this, we developed a novel TaqMan quantitative PCR (qPCR) and digital droplet PCR (ddPCR) methods for astrovirus detection and absolute quantitative analysis. We also performed high-throughput sequencing to obtain the complete genome sequences and establish the genetic similarity of the obtained strains to known astroviruses of poultry and other avian species. Two new complete genome sequences of pigeon astroviruses in the Avastrovirus genus were identified, representing 2 new species. These were found most closely related to astroviruses identified in Columbidae species and chickens. They share an average of 75.8% genome-wide pairwise identity and 57.6% and 64.6% capsid protein sequence identity with other unclassified columbid avastrovirus sequences in GenBank. Although the difference in prevalence of astrovirus in the study and control group was found statistically insignificant, there was a significant difference between the number of genome copies in positive samples from both groups. These unambiguous results leave the role of astroviruses as enteropathogenic factors in pigeons still undetermined.
Assuntos
Infecções por Astroviridae , Avastrovirus , Doenças das Aves , Columbidae , Genoma Viral , Filogenia , Animais , Columbidae/virologia , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Infecções por Astroviridae/epidemiologia , Doenças das Aves/virologia , Doenças das Aves/epidemiologia , Avastrovirus/genética , Avastrovirus/isolamento & purificação , Avastrovirus/classificaçãoRESUMO
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
Goose astroviruses (GAstVs) are important pathogens which can cause gout in goslings leading to huge economic losses for the goose farming industry in China. In 2023, an infectious disease characterized by visceral gout broke out in commercial goose farms in Guangxi and Guangdong provinces of China. In this study, two GAstV strains of GXNN and GDCS were successfully isolated from these two disease-ridden goose farms. The complete genomic lengths of these two strains were 7166 bp, and phylogenetic analysis showed that they were both GAstV-2 subtypes. The 3-dimensional structures of the capsid protein were predicted and six characteristic mutation sites at amino acid positions 60, 61, 228, 229, 456 and 523 were found within the strong antigenic regions. A recombination event occurred at 6833-7070 nt between the GAstV TZ03 and Turkey astrovirus CA/00 and this was detected in both the GXNN and GDCS strains. Another recombinant event occurred at 63-2747 nt between the GAstV XT1 and GAstV SDPY and this was detected in the GDCS strain. When 1-day-old goslings were infected with the novel GXNN and GDCS strains, they showed severe visceral gout. This was accompanied by enlarged spleens, liver hemorrhages and urate deposits in the kidneys and ureters and their blood urea nitrogen levels were significantly elevated. The mortality rates of the GXNN- and GDCS-infected groups were pathogenically high at 80 % and 60 %, respectively. These results will promote our understanding of the evolution and epidemic potential of GAstVs in China.
Assuntos
Infecções por Astroviridae , Proteínas do Capsídeo , Gansos , Genoma Viral , Gota , Filogenia , Doenças das Aves Domésticas , Animais , Gansos/virologia , China , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/patologia , Gota/virologia , Gota/veterinária , Gota/patologia , Proteínas do Capsídeo/genética , Avastrovirus/genética , Avastrovirus/patogenicidade , Avastrovirus/isolamento & purificação , Avastrovirus/classificação , Virulência , Astroviridae/genética , Astroviridae/isolamento & purificação , Astroviridae/patogenicidadeRESUMO
Astroviruses are highly divergent and infect a wide variety of animal hosts. In 2009, a genetically divergent human astrovirus (HAstV) strain VA1 was first identified in an outbreak of acute gastroenteritis. This strain has also been associated with fatal central nervous system disease. In this work, we report the isolation of three high-affinity neutralizing monoclonal antibodies (Nt-MAbs) targeting the capsid spike domain of HAstV-VA1. These antibodies (7C8, 2A2, 3D8) were used to select individual HAstV-VA1 mutants resistant to their neutralizing activity and a HAstV-VA1 triple mutant that escapes neutralization from all three Nt-MAbs. Sequencing of the virus genome capsid region revealed escape mutations that map to the surface of the capsid spike domain, define three potentially independent neutralization epitopes, and help delineate four antigenic sites in human astroviruses. Notably, two of the escape mutations were found to be present in the spike sequence of the HAstV-VA1-PS strain isolated from an immunodeficient patient with encephalitis, suggesting that those mutations arose as a result of the immune pressure generated by the patient's immunotherapy. In agreement with this observation, human serum samples exhibiting strong neutralization activity against wild-type HAstV-VA1 had a 2.6-fold reduction in neutralization titer when evaluated against the triple-escape HAstV-VA1 mutant, suggesting that both mouse and human antibody responses target shared neutralization epitopes. The isolated Nt-MAbs reported in this work will help to characterize the functional domains of the virus during cell entry and have the potential for developing a specific antibody therapy for the neurological disease associated with HAstV-VA1. IMPORTANCE: Human astroviruses (HAstVs) have been historically associated with acute gastroenteritis. However, the genetically divergent HAstV-VA1 strain has been associated with central nervous system disease. In this work high-affinity neutralizing monoclonal antibodies directed to HAstV-VA1 were isolated and characterized. The proposed binding sites for these antibodies and for neutralizing antibodies against classical HAstVs suggest that there are at least four neutralization sites on the capsid spike of astroviruses. Our data show that natural infection with human astrovirus VA1 elicits a robust humoral immune response that targets the same antigenic sites recognized by the mouse monoclonal antibodies and strongly suggests the emergence of a variant HAstV-VA1 virus in an immunodeficient patient with prolonged astrovirus infection. The isolated Nt-MAb reported in this work will help to define the functional sites of the virus involved in cell entry and hold promise for developing a specific antibody therapy for the neurological disease associated with HAstV-VA1.
Assuntos
Anticorpos Monoclonais , Anticorpos Neutralizantes , Anticorpos Antivirais , Epitopos , Humanos , Animais , Anticorpos Neutralizantes/imunologia , Camundongos , Epitopos/imunologia , Anticorpos Antivirais/imunologia , Anticorpos Monoclonais/imunologia , Proteínas do Capsídeo/imunologia , Proteínas do Capsídeo/genética , Mamastrovirus/imunologia , Mamastrovirus/genética , Mutação , Infecções por Astroviridae/imunologia , Infecções por Astroviridae/virologia , Testes de NeutralizaçãoRESUMO
BACKGROUND: This study presents the case of non-purulent encephalomyelitis associated with astrovirus infection in a sheep from Eastern Anatolia, Türkiye. METHODS: A necropsy was performed on a sheep showing nervous signs. Afterwards, brain tissue samples were taken and examined with histopathological, immunohistochemical and molecular techniques. RESULTS: Neuropathologic changes included neuronal degeneration, diffuse gliosis, multifocal perivascular cuffing, neuronophagy and neuronal necrosis in the cerebrum, the cerebellum and the cervical spinal cord. Aerobic and anaerobic bacterial culture, selective culture for Listeria monocytogenes, and PCR analysis for rabies virus, tick-borne encephalitis virus, Türkiye encephalitis virus, small ruminant lentiviruses and border disease virus were negative. However, the presence of astrovirus RNA in cerebral, cerebellar and spinal cord samples was demonstrated by a pan-astrovirus RT-PCR. Immunohistochemical examinations revealed astrovirus antigens within the neuronal cytoplasm. High-throughput sequencing techniques identified the causative agent as a member of the genotype species Mamastrovirus 13 but representing a distinct genetic lineage with similarity to ovine astrovirus 1 in the open-reading frames (ORF)1ab region and muskox astrovirus in the ORF2 region. CONCLUSION: This report provides evidence that astroviruses are potentially encephalitis-causing pathogens in ovine populations in Türkiye, featuring an astrovirus strain distinct from those previously identified in sheep.
Assuntos
Infecções por Astroviridae , Sequenciamento de Nucleotídeos em Larga Escala , Doenças dos Ovinos , Animais , Ovinos , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Doenças dos Ovinos/virologia , Doenças dos Ovinos/patologia , Sequenciamento de Nucleotídeos em Larga Escala/veterinária , Encefalomielite/veterinária , Encefalomielite/virologia , Carneiro Doméstico , Astroviridae/isolamento & purificação , Astroviridae/genética , Mamastrovirus/isolamento & purificação , Mamastrovirus/genética , FilogeniaRESUMO
Porcine astrovirus (PAstV) has a potential zoonotic risk, with a high proportion of co-infection occurring with porcine epidemic diarrhea virus (PEDV) and other diarrheal pathogens. Despite its high prevalence, the cellular mechanism of PAstV pathogenesis is ill-defined. Previous proteomics analyses have revealed that the differentially expressed protein NOD-like receptor X1 (NLRX1) located in the mitochondria participates in several important antiviral signaling pathways in PAstV-4 infection, which are closely related to mitophagy. In this study, we confirmed that PAstV-4 infection significantly up-regulated NLRX1 and mitophagy in Caco-2 cells, while the silencing of NLRX1 or the treatment of mitophagy inhibitor 3-MA inhibited PAstV-4 replication. Additionally, PAstV-4 infection triggered the activation of the extracellular regulated protein kinases/ myosin light-chain kinase (ERK/MLCK) pathway, followed by the down-regulation of tight-junction proteins (occludin and ZO-1) as well as MUC-2 expression. The silencing of NLRX1 or the treatment of 3-MA inhibited myosin light-chain (MLC) phosphorylation and up-regulated occludin and ZO-1 proteins. Treatment of the ERK inhibitor PD98059 also inhibited MLC phosphorylation, while MLCK inhibitor ML-7 mitigated the down-regulation of mucosa-related protein expression induced by PAstV-4 infection. Yet, adding PD98059 or ML-7 did not affect NLRX1 expression. In summary, this study preliminarily explains that NLRX1 plays an important role in the disruption of intestinal mucosal function triggered by PAstV-4 infection via the ERK/MLC pathway. It will be helpful for further antiviral drug target screening and disease therapy.
Assuntos
Mucosa Intestinal , Quinase de Cadeia Leve de Miosina , Animais , Mucosa Intestinal/metabolismo , Mucosa Intestinal/virologia , Mucosa Intestinal/patologia , Células CACO-2 , Humanos , Suínos , Quinase de Cadeia Leve de Miosina/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Infecções por Astroviridae/virologia , Mamastrovirus/fisiologia , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Doenças dos Suínos/virologia , Doenças dos Suínos/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Small terrestrial mammals are major hosts of infectious agents responsible for zoonotic diseases. Astroviruses (AstVs)-the cause of non-bacterial gastroenteritis mainly affecting young children-have been detected in a wide array of mammalian and avian host species. However, understanding the factors that influence AstV infection within and across hosts is limited. Here, we investigated the impact of land use changes on AstVs in terrestrial small mammals in rural northeastern Madagascar. We sampled 515 small mammals, representing seven endemic and four introduced species. Twenty-two positive samples were identified, all but one of which were found in the introduced species Mus musculus and Rattus rattus (family Muridae), with a positivity rate of 7.7% (6/78) and 5.6% (15/266), respectively. The non-introduced rodent case was from an endemic shrew-tenrec (family Tenrecidae). We found the highest positivity rate of AstVs infection in brushy regrowth (17.5%, 7/40) as compared to flooded rice fields (4.60%, 8/174), secondary forest (4.1%, 3/74), agroforest (3.6%, 1/28), village (2.61%, 3/115), and semi-intact forest (0%, 0/84). A phylogenetic analysis revealed an association between AstVs and their rodent host species. None of the viruses were phylogenetically related to AstVs previously described in Malagasy bats. This study supports AstV circulation in synanthropic animals in agricultural habitats of Madagascar and highlights the need to assess the spillover risk to human populations in rural areas.
Assuntos
Infecções por Astroviridae , Astroviridae , Animais , Madagáscar/epidemiologia , Infecções por Astroviridae/veterinária , Infecções por Astroviridae/virologia , Infecções por Astroviridae/epidemiologia , Astroviridae/genética , Astroviridae/isolamento & purificação , Astroviridae/classificação , Camundongos , Filogenia , Ratos , Mamíferos/virologia , Zoonoses/virologia , Zoonoses/transmissãoRESUMO
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
Goose astrovirus (GoAstV) is an emerging avian pathogen that induces gout in goslings with a mortality of up to 50%. Organ damage caused by GoAstV infection was considered the cause of gout, but it is still unclear whether other factors are involved. Human and murine studies have linked the gut microbiome-derived urate and gout, thus we hypothesized that gut microbiome may also play an important role in gout induced by GoAstV infection. This study tested the pathogenicity of our isolated GoAstV genotype 2 strain on goslings, while the appearance of clinical signs, histopathological changes, viral distribution and the blood level of cytokines were monitored for 18 d postinfection (dpi). The dynamics in the gut microbiome were profiled by 16S sequencing and then correlated with GoAstV infection. Results showed that this study successfully developed an experimental infection model for studying the pathogenicity of the GoAstV infection which induces typical symptoms of gout. GoAstV infection significantly altered the gut microbiome of goslings with the enrichment of potential proinflammatory bacteria and depletion of beneficial bacteria that can produce short-chain fatty acids. More importantly, the microbial pathway involved in urate production was significantly increased in goslings infected with GoAstV, suggesting that gut microbiome-derived urate may also contribute to the gout symptoms. Overall, this study demonstrated the role of gut microbiome in the pathogenesis of GoAstV infection, highlighting the potential of gut microbiome-based therapeutics against gout symptoms.