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Viruses May 2017Astroviruses are a diverse family of viruses that infect a wide range of mammalian and avian hosts. Here we describe the phylogenetic diversity and current... (Review)
Review
Astroviruses are a diverse family of viruses that infect a wide range of mammalian and avian hosts. Here we describe the phylogenetic diversity and current classification methodology of astroviruses based on the ORF1b and ORF2 genes, highlighting the propensity of astroviruses to undergo interspecies transmission and genetic recombination which greatly increase diversity and complicate attempts at a unified and comprehensive classification strategy.
Topics: Animals; Astroviridae; Astroviridae Infections; Birds; Capsid Proteins; Feces; Genetic Variation; Host Specificity; Humans; Mammals; Mice; Open Reading Frames; Phylogeny; RNA-Dependent RNA Polymerase; Rats; Recombination, Genetic; Viral Proteins
PubMed: 28489047
DOI: 10.3390/v9050102 -
Scandinavian Journal of Immunology Jan 2022This mini-review describes observations of the 1990ies with culturing of gluten-specific and astrovirus-specific CD4 T cells from duodenal biopsies from subjects who... (Review)
Review
This mini-review describes observations of the 1990ies with culturing of gluten-specific and astrovirus-specific CD4 T cells from duodenal biopsies from subjects who presumably had a long time between the exposure to gluten or astrovirus antigens and the sampling of the biopsy. In these studies, it was also observed that antigen-specific CD4 T cells migrated out of the gut biopsies during overnight culture. The findings are suggestive of memory T cells in tissue which are resident, but which also can be mobilised on antigen stimulation. Of note, these findings were made years before the term tissue-resident memory T cells was invoked. Since that time, many observations have accumulated on these gut T cells, particularly the gluten-specific T cells, and we have insight into the turnover of CD4 T cells in the gut lamina propria. These data make it evident that human antigen-specific CD4 T cells that can be cultured from gut biopsies indeed are bone fide tissue-resident memory T cells.
Topics: Animals; Astroviridae Infections; Autoantigens; Celiac Disease; Glutens; Humans; Immunologic Memory; Intestinal Mucosa; Mamastrovirus; Memory T Cells; Organ Specificity
PubMed: 34796982
DOI: 10.1111/sji.13120 -
International Journal of Molecular... Sep 2022Avian astroviruses, including chicken astrovirus (CAstV), avian nephritisvirus (ANV), and goose astrovirus (GoAstV), are ubiquitous enteric RNA viruses associated with... (Review)
Review
Avian astroviruses, including chicken astrovirus (CAstV), avian nephritisvirus (ANV), and goose astrovirus (GoAstV), are ubiquitous enteric RNA viruses associated with enteric disorders in avian species. Recent research has found that infection of these astroviruses usually cause visceral gout in chicken, duckling and gosling. However, the underlying mechanism remains unknown. In the current article, we review recent discoveries of genetic diversity and variation of these astroviruses, as well as pathogenesis after astrovirus infection. In addition, we discuss the relation between avian astrovirus infection and visceral gout in poultry. Our aim is to review recent discoveries about the prevention and control of the consequential visceral gout diseases in poultry, along with the attempt to reveal the possible producing process of visceral gout diseases in poultry.
Topics: Animals; Astroviridae Infections; Avastrovirus; Geese; Gout; Phylogeny; Poultry; Poultry Diseases
PubMed: 36142340
DOI: 10.3390/ijms231810429 -
Viruses Dec 2020An 8-year-old alpaca was admitted to the emergency service of the Clinic for Ruminants in Bern due to a reduced general condition and progressive neurological signs....
An 8-year-old alpaca was admitted to the emergency service of the Clinic for Ruminants in Bern due to a reduced general condition and progressive neurological signs. Despite supportive treatment, its condition deteriorated and the animal had to be euthanized. Histopathological analysis revealed a severe non-suppurative polioencephalomyelitis with neuronal necrosis, most likely of viral origin. We detected abundant neuronal labelling with antibodies directed against two different epitopes of Bovine Astrovirus CH13/NeuroS1 (BoAstV-CH13/NeuroS1), which is a common viral agent associated with non-suppurative encephalitis in Swiss cattle. These findings were further verified by detection of viral RNA by use of in-situ hybridization and real-time RT-PCR. Next generation sequencing revealed that the detected virus genome had a pairwise identity of 98.9% to the genome of BoAstV-CH13/NeuroS1. To our knowledge, this is the first report of an astrovirus-associated polioencephalomyelitis in an alpaca. These results point to the possibility of an interspecies transmission of BoAstV-CH13/NeuroS1.
Topics: Animals; Astroviridae; Astroviridae Infections; Biopsy; Brain; Cattle; Cattle Diseases; Immunohistochemistry; In Situ Hybridization; Poliomyelitis; RNA, Viral; Real-Time Polymerase Chain Reaction
PubMed: 33396858
DOI: 10.3390/v13010050 -
Journal of Virology Aug 2020Wild birds are major natural reservoirs and potential dispersers of a variety of infectious diseases. As such, it is important to determine the diversity of viruses they...
Wild birds are major natural reservoirs and potential dispersers of a variety of infectious diseases. As such, it is important to determine the diversity of viruses they carry and use this information to help understand the potential risks of spillover to humans, domestic animals, and other wildlife. We investigated the potential viral causes of paresis in long-standing, but undiagnosed, disease syndromes in wild Australian birds. RNA from diseased birds was extracted and pooled based on tissue type, host species, and clinical manifestation for metagenomic sequencing. Using a bulk and unbiased metatranscriptomic approach, combined with clinical investigation and histopathology, we identified a number of novel viruses from the families , and in common urban wild birds, including Australian magpies, magpie larks, pied currawongs, Australian ravens, and rainbow lorikeets. In each case, the presence of the virus was confirmed by reverse transcription (RT)-PCR. These data revealed a number of candidate viral pathogens that may contribute to coronary, skeletal muscle, vascular, and neuropathology in birds of the and families and neuropathology in members of the The existence of such a diverse virome in urban avian species highlights the importance and challenges in elucidating the etiology and ecology of wildlife pathogens in urban environments. This information will be increasingly important for managing disease risks and conducting surveillance for potential viral threats to wildlife, livestock, and human health. Wildlife naturally harbor a diverse array of infectious microorganisms and can be a source of novel diseases in domestic animals and human populations. Using unbiased RNA sequencing, we identified highly diverse viruses in native birds from Australian urban environments presenting with paresis. This research included the clinical investigation and description of poorly understood recurring syndromes of unknown etiology: clenched claw syndrome and black and white bird disease. As well as identifying a range of potentially disease-causing viral pathogens, this study describes methods that can effectively and efficiently characterize emergent disease syndromes in free-ranging wildlife and promotes further surveillance for specific pathogens of potential conservation and zoonotic concern.
Topics: Adenoviridae; Animals; Animals, Wild; Astroviridae; Australia; Bird Diseases; Birds; Circoviridae; Cities; DNA Virus Infections; High-Throughput Nucleotide Sequencing; Humans; Metagenome; Paramyxoviridae; Parvoviridae; Phylogeny; Picornaviridae; Polyomaviridae; RNA Virus Infections; Transcriptome
PubMed: 32581107
DOI: 10.1128/JVI.00606-20 -
Veterinary Research Communications Dec 2022In this study, the aetiological background of an outbreak of severe haemorrhagic gastroenteritis (HGE) in a colony of purebred Jack Russell Terriers vaccinated against...
Unusual "Asian-origin" 2c to 2b point mutant canine parvovirus (Parvoviridae) and canine astrovirus (Astroviridae) co-infection detected in vaccinated dogs with an outbreak of severe haemorrhagic gastroenteritis with high mortality rate in Hungary.
In this study, the aetiological background of an outbreak of severe haemorrhagic gastroenteritis (HGE) in a colony of purebred Jack Russell Terriers vaccinated against CPV-2 in Hungary was investigated. Canine parvovirus 2 (CPV-2, Parvoviridae) and canine astrovirus (CaAstV, Astroviridae) co-infection was identified by viral metagenomics and next-generation sequencing (VM-NGS) methods from a rectal swab of an affected 7-week-old puppy. The complete coding sequence of CPV-2 strain FR1/CPV2-2021-HUN (ON733252) and the complete genome of CaAstV strain FR1/CaAstV-2021-HUN (ON733251) were determined by VM-NGS and PCR methods. Results of sequence and phylogenetic analyses showed that CPV-2 strain FR1/CPV2-2021-HUN was different from the applied vaccine strains and previously identified strains from Hungary but showed high sequence identity (> 99.8%) and close phylogenetic relationship to recently described "Asian-origin" CPV-2c strains from Italy. But, based on the single amino acid difference on position 426 of VP2 (Glu/Asp) between the study strain and the closest relatives, FR1/CPV2-2021-HUN belonged to the 2b antigenic type rather than 2c. The CaAstV strain FR1/CaAstV-2021-HUN showed close relationship with a CaAstV strain identified previously from a diarrhoeic dog in Hungary. Both viruses were continuously detectable by PCR in additional enteric samples, and the CPV-2 could also be detected in several (n = 32) tissue samples from 9 affected deceased puppies. Further comparative studies are necessary to confirm the role of the point mutation causing the change in the antigenic type of this "Asian-origin" CPV-2 and/or the role of CaAstV co-infection in the development and/or severity of (haemorrhagic) gastroenteritis among dogs vaccinated against CPV-2.
Topics: Dogs; Animals; Parvovirus, Canine; Astroviridae; Parvoviridae; Phylogeny; Coinfection; Hungary; Parvoviridae Infections; Dog Diseases; Gastroenteritis; Disease Outbreaks
PubMed: 36129562
DOI: 10.1007/s11259-022-09997-2 -
Journal of Virology Sep 2023Human astrovirus is a positive-sense, single-stranded RNA virus. Astrovirus infection causes gastrointestinal symptoms and can lead to encephalitis in immunocompromised...
Human astrovirus is a positive-sense, single-stranded RNA virus. Astrovirus infection causes gastrointestinal symptoms and can lead to encephalitis in immunocompromised patients. Positive-strand RNA viruses typically utilize host intracellular membranes to form replication organelles, which are potential antiviral targets. Many of these replication organelles are double-membrane vesicles (DMVs). Here, we show that astrovirus infection leads to an increase in DMV formation through a replication-dependent mechanism that requires some early components of the autophagy machinery. Results indicate that the upstream class III phosphatidylinositol 3-kinase (PI3K) complex, but not LC3 conjugation machinery, is utilized in DMV formation. Both chemical and genetic inhibition of the PI3K complex lead to significant reduction in DMVs, as well as viral replication. Elucidating the role of autophagy machinery in DMV formation during astrovirus infection reveals a potential target for therapeutic intervention for immunocompromised patients. IMPORTANCE These studies provide critical new evidence that astrovirus replication requires formation of double-membrane vesicles, which utilize class III phosphatidylinositol 3-kinase (PI3K), but not LC3 conjugation autophagy machinery, for biogenesis. These results are consistent with replication mechanisms for other positive-sense RNA viruses suggesting that targeting PI3K could be a promising therapeutic option for not only astrovirus, but other positive-sense RNA virus infections.
Topics: Humans; Autophagy; Class III Phosphatidylinositol 3-Kinases; Intracellular Membranes; Organelles; Phosphatidylinositol 3-Kinase; RNA Viruses; Virus Replication; Mamastrovirus; Signal Transduction
PubMed: 37668367
DOI: 10.1128/jvi.01025-23 -
Viruses Feb 2017Bats belong to the order Chiroptera that represents the second largest order of mammals with more than 1200 species and an almost global distribution. Environmental... (Review)
Review
Bats belong to the order Chiroptera that represents the second largest order of mammals with more than 1200 species and an almost global distribution. Environmental changes and deforestation have severely influenced many ecosystems, intensifying the contact between wildlife and humans. In recent years, bats have been found to harbor a number of different viruses with zoonotic potential, as well as a great diversity of astroviruses, for which the question of zoonotic potential remains unanswered to date. Human astroviruses have been identified as the causative agent for diarrhea in children and immunocompromised patients. For a long time, astroviruses have been considered to be strictly species-specific. However, a great genetic diversity has recently been discovered among animal and human astroviruses that might indicate the potential of these viruses to cross species barriers. Furthermore, our knowledge about the tissue tropism of astroviruses has been expanded to some neurotropic strains that have recently been shown to be responsible for encephalitis in humans and livestock. This review gives an overview on what is known about astroviruses in bats, humans and livestock, especially bovines and pigs. Future research activities are suggested to unravel astrovirus infection dynamics in bat populations to further assess the zoonotic potential of these viruses.
Topics: Animals; Astroviridae Infections; Chiroptera; Humans; Livestock; Mamastrovirus
PubMed: 28230787
DOI: 10.3390/v9020034 -
Pediatrics Jan 2018Astroviruses are important drivers of viral gastroenteritis but remain understudied in community settings and low- and middle-income countries. We present data from 8...
BACKGROUND AND OBJECTIVES
Astroviruses are important drivers of viral gastroenteritis but remain understudied in community settings and low- and middle-income countries. We present data from 8 countries with high prevalence of diarrhea and undernutrition to describe astrovirus epidemiology and assess evidence for protective immunity among children 0 to 2 years of age.
METHODS
We used 25 898 surveillance stools and 7077 diarrheal stools contributed by 2082 children for enteropathogen testing, and longitudinal statistical analysis to describe incidence, risk factors, and protective immunity.
RESULTS
Thirty-five percent of children experienced astrovirus infections. Prevalence in diarrheal stools was 5.6%, and severity exceeded all enteropathogens except rotavirus. Incidence of infection and diarrhea were 2.12 and 0.88 episodes per 100 child-months, respectively. Children with astrovirus infection had 2.30 times the odds of experiencing diarrhea after adjustment for covariates (95% confidence interval [CI], 2.01-2.62; < .001). Undernutrition was a risk factor: odds of infection and diarrhea were reduced by 10% and 13%, respectively, per increase in length-for-age score (infection: odds ratio, 0.90 [95% CI, 0.85-0.96]; < .001; diarrhea: odds ratio, 0.87 [95% CI, 0.79-0.96]; = .006). Some evidence of protective immunity to infection was detected (hazard ratio, 0.84 [95% CI, 0.71-1.00], = .052), although this was heterogeneous between sites and significant in India and Peru.
CONCLUSIONS
Astrovirus is an overlooked cause of diarrhea among vulnerable children worldwide. With the evidence presented here, we highlight the need for future research as well as the potential for astrovirus to be a target for vaccine development.
Topics: Age Distribution; Astroviridae Infections; Child, Preschool; Developing Countries; Diarrhea; Disease Outbreaks; Female; Humans; Infant; Longitudinal Studies; Male; Mamastrovirus; Prevalence; Retrospective Studies; Risk Assessment; Severity of Illness Index; Sex Distribution; Socioeconomic Factors
PubMed: 29259078
DOI: 10.1542/peds.2017-1326 -
Infection, Genetics and Evolution :... Mar 2018Environmental modifications are leading to biodiversity changes, loss and habitat disturbance. This in turn increases contacts between wildlife and hence the risk of...
Environmental modifications are leading to biodiversity changes, loss and habitat disturbance. This in turn increases contacts between wildlife and hence the risk of transmission and emergence of zoonotic diseases. We analyzed the environment and land use using remote spatial data around the sampling locations of bats positive for coronavirus (21 sites) and astrovirus (11 sites) collected in 43 sites. A clear association between viruses and hosts was observed. Viruses associated to synanthropic bat genera, such as Myotis or Scotophilus were associated to highly transformed habitats with human presence while viruses associated to fruit bat genera were correlated with natural environments with dense forest, grassland areas and regions of high elevation. In particular, group C betacoronavirus were associated with mosaic habitats found in anthropized environments.
Topics: Animals; Astroviridae; Cambodia; Chiroptera; Cluster Analysis; Coronavirus; Environmental Microbiology; Genetic Variation; Humans; Laos; Mice; Phylogeny; Phylogeography; RNA Viruses; Zoonoses
PubMed: 29277555
DOI: 10.1016/j.meegid.2017.12.009