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Voprosy Virusologii Dec 2023Bastroviruses were discovered in the Netherlands in 2016 in human stool samples and show partial genetic similarities to astroviruses and hepatitis E viruses. Their...
INTRODUCTION
Bastroviruses were discovered in the Netherlands in 2016 in human stool samples and show partial genetic similarities to astroviruses and hepatitis E viruses. Their association with disease onset has not yet been established.
MATERIALS AND METHODS
Metagenomic sequencing of fecal samples of bats collected in the Russian Federation in 2023 was performed. Two almost complete genomes of bastroviruses were assembled. The zoonotic potential of these viruses was assessed using machine learning methods, their recombination was studied, and phylogenetic trees were constructed.
RESULTS
A nearly complete bastrovirus genome was de novo assembled in one of the samples, and it was used to assemble another genome in another sample. The zoonotic potential of the virus from one of these samples was estimated as high. The existence of recombination between structural and non-structural polyproteins was demonstrated.
CONCLUSION
Two bastrovirus genomes were assembled, phylogenetic and recombination analyses were performed, and the zoonotic potential was evaluated.
Topics: Animals; Humans; Astroviridae; Astroviridae Infections; Phylogeny; Chiroptera; Genetic Variation
PubMed: 38156566
DOI: 10.36233/0507-4088-192 -
Viruses Jan 2017Astroviruses are a major cause of diarrhea in the young, elderly, and the immunocompromised. Since the discovery of human astrovirus type 1 (HAstV-1) in 1975, the family... (Review)
Review
Astroviruses are a major cause of diarrhea in the young, elderly, and the immunocompromised. Since the discovery of human astrovirus type 1 (HAstV-1) in 1975, the family has expanded to include two more human clades and numerous mammalian and avian-specific genotypes. Despite this, there is still little known about pathogenesis. The following review highlights the current knowledge of astrovirus pathogenesis, and outlines the critical steps needed to further astrovirus research, including the development of animal models of cell culture systems.
Topics: Animals; Astroviridae; Astroviridae Infections; Host-Pathogen Interactions; Humans
PubMed: 28117758
DOI: 10.3390/v9010022 -
Viruses Jan 2017Various methods exist to detect an astrovirus infection. Current methods include electron microscopy (EM), cell culture, immunoassays, polymerase chain reaction (PCR)... (Review)
Review
Various methods exist to detect an astrovirus infection. Current methods include electron microscopy (EM), cell culture, immunoassays, polymerase chain reaction (PCR) and various other molecular approaches that can be applied in the context of diagnostic or in surveillance studies. With the advent of metagenomics, novel human astrovirus (HAstV) strains have been found in immunocompromised individuals in association with central nervous system (CNS) infections. This work reviews the past and current methods for astrovirus detection and their uses in both research laboratories and for medical diagnostic purposes.
Topics: Astroviridae; Astroviridae Infections; Diagnostic Tests, Routine; Humans; Microbiological Techniques
PubMed: 28085120
DOI: 10.3390/v9010010 -
Current Opinion in Virology Aug 2019Although astroviruses are most commonly associated with acute gastrointestinal illness in humans, their ability to infect a broad range of hosts and cause a spectrum of... (Review)
Review
Although astroviruses are most commonly associated with acute gastrointestinal illness in humans, their ability to infect a broad range of hosts and cause a spectrum of disease makes them widespread and complex pathogens. The precise mechanisms that dictate the course of astrovirus disease have not been studied extensively but are likely driven by multifactorial host-microbe interactions. Recent insights from studies of animal astrovirus infections have revealed both beneficial and detrimental effects for the host. However, further in-depth studies are needed to fully explore the consequences of astrovirus-induced changes in the gut microenvironment as well as the role of the microbiota in astrovirus infection.
Topics: Animals; Astroviridae; Astroviridae Infections; Birds; Chiroptera; Gastroenteritis; Gastrointestinal Microbiome; Host Microbial Interactions; Humans; Mamastrovirus; Mice; Microbial Interactions; RNA Viruses
PubMed: 31163291
DOI: 10.1016/j.coviro.2019.05.002 -
Viruses Jun 2021Astrovirus infections are among the main causes of diarrhea in children, but their significance for animal health has remained underestimated and largely unknown. This... (Review)
Review
Astrovirus infections are among the main causes of diarrhea in children, but their significance for animal health has remained underestimated and largely unknown. This is changing due to the increasing amount of newly identified neurotropic astroviruses in cases of nonsuppurative encephalitis and neurological disease in humans, pigs, ruminant species and minks. Neurological cases in ruminants and humans usually occur sporadically and as isolated cases. This contrasts with the situation in pigs and minks, in which diseases associated with neurotropic astroviruses are endemic and occur on the herd level. Affected animals show neurological signs such as mild ataxia to tetraplegia, loss of orientation or trembling, and the outcome is often fatal. Non-suppurative inflammation with perivascular cuffing, gliosis and neuronal necrosis are typical histological lesions of astrovirus encephalitis. Since astroviruses primarily target the gastrointestinal tract, it is assumed that they infect the brain through the circulatory system or retrograde following the nerves. The phylogenetic analysis of neurotropic astroviruses has revealed that they are genetically closely related, suggesting the presence of viral determinants for tissue tropism and neuroinvasion. In this review, we summarize the current knowledge on neurotropic astrovirus infections in animals and propose future research activities.
Topics: Animals; Astroviridae; Astroviridae Infections; Brain; Encephalitis, Viral; Genome, Viral; Nervous System Diseases; Phylogeny
PubMed: 34201545
DOI: 10.3390/v13071201 -
Infection, Genetics and Evolution :... Apr 2019Astroviruses are small, non-enveloped, positive-sense, single-stranded RNA viruses that belong to the Astroviridae family. Astroviruses infect diverse hosts and are... (Review)
Review
Astroviruses are small, non-enveloped, positive-sense, single-stranded RNA viruses that belong to the Astroviridae family. Astroviruses infect diverse hosts and are typically associated with gastrointestinal illness; although disease can range from asymptomatic to encephalitis depending on the host and viral genotype. Astroviruses have high genetic variability due to an error prone polymerase and frequent recombination events between strains. Once thought to be species specific, recent evidence suggests astroviruses can spread between different host species, although the frequency with which this occurs and the restrictions that regulate the process are unknown. Recombination events can lead to drastic evolutionary changes and contribute to cross-species transmission events. This work reviews the current state of research on astrovirus evolution and emergence, especially as it relates to cross-species transmission and recombination of astroviruses.
Topics: Animals; Astroviridae; Astroviridae Infections; Biological Evolution; Communicable Diseases, Emerging; Evolution, Molecular; Genome, Viral; Genomics; Host-Pathogen Interactions; Humans; Mutation; Recombination, Genetic; Viral Tropism
PubMed: 30639546
DOI: 10.1016/j.meegid.2019.01.009 -
Clinical Microbiology Reviews Oct 2014Human astroviruses (HAtVs) are positive-sense single-stranded RNA viruses that were discovered in 1975. Astroviruses infecting other species, particularly mammalian and... (Review)
Review
Human astroviruses (HAtVs) are positive-sense single-stranded RNA viruses that were discovered in 1975. Astroviruses infecting other species, particularly mammalian and avian, were identified and classified into the genera Mamastrovirus and Avastrovirus. Through next-generation sequencing, many new astroviruses infecting different species, including humans, have been described, and the Astroviridae family shows a high diversity and zoonotic potential. Three divergent groups of HAstVs are recognized: the classic (MAstV 1), HAstV-MLB (MAstV 6), and HAstV-VA/HMO (MAstV 8 and MAstV 9) groups. Classic HAstVs contain 8 serotypes and account for 2 to 9% of all acute nonbacterial gastroenteritis in children worldwide. Infections are usually self-limiting but can also spread systemically and cause severe infections in immunocompromised patients. The other groups have also been identified in children with gastroenteritis, but extraintestinal pathologies have been suggested for them as well. Classic HAstVs may be grown in cells, allowing the study of their cell cycle, which is similar to that of caliciviruses. The continuous emergence of new astroviruses with a potential zoonotic transmission highlights the need to gain insights on their biology in order to prevent future health threats. This review focuses on the basic virology, pathogenesis, host response, epidemiology, diagnostic assays, and prevention strategies for HAstVs.
Topics: Astroviridae Infections; Host-Pathogen Interactions; Humans; Mamastrovirus
PubMed: 25278582
DOI: 10.1128/CMR.00013-14 -
Annual Review of Virology Sep 2017Astroviruses are nonenveloped, positive-sense single-stranded RNA viruses that cause gastrointestinal illness. Although a leading cause of pediatric diarrhea, human... (Review)
Review
Astroviruses are nonenveloped, positive-sense single-stranded RNA viruses that cause gastrointestinal illness. Although a leading cause of pediatric diarrhea, human astroviruses are among the least characterized enteric RNA viruses. However, by using in vitro methods and animal models to characterize virus-host interactions, researchers have discovered several important properties of astroviruses, including the ability of the astrovirus capsid to act as an enterotoxin, disrupting the gut epithelial barrier. Improved animal models are needed to study this phenomenon, along with the pathogenesis of astroviruses, particularly in those strains that can cause extraintestinal disease. Much like for other enteric viruses, the current dogma states that astroviruses infect in a species-specific manner; however, this assumption is being challenged by growing evidence that these viruses have potential to cross species barriers. This review summarizes these remarkable facets of astrovirus biology, highlighting critical steps toward increasing our understanding of this unique enteric pathogen.
Topics: Animals; Astroviridae Infections; Capsid; Chickens; Diarrhea; Disease Models, Animal; Gastroenteritis; Humans; Intestinal Mucosa; Mamastrovirus; Mice; Permeability; Phylogeny; Species Specificity; Swine
PubMed: 28715976
DOI: 10.1146/annurev-virology-101416-041742 -
Viruses Mar 2022Porcine sapeloviruses, teschoviruses of family and type 3 porcine astroviruses of family are (re-)emerging enteric pathogens that could be associated with severe,...
Development and Large-Scale Testing of a Novel One-Step Triplex RT-qPCR Assay for Simultaneous Detection of "Neurotropic" Porcine Sapeloviruses, Teschoviruses () and Type 3 Porcine Astroviruses () in Various Samples including Nasal Swabs.
Porcine sapeloviruses, teschoviruses of family and type 3 porcine astroviruses of family are (re-)emerging enteric pathogens that could be associated with severe, disseminated infections in swine, affecting multiple organs including the central nervous system (CNS). Furthermore, small-scale pioneer studies indicate the presence of these viruses in porcine nasal samples to various extents. The laboratory diagnostics are predominantly based on the detection of the viral RNA from faecal and tissue samples using different nucleic-acid-based techniques such as RT-qPCR. In this study, a novel highly sensitive one-step triplex RT-qPCR assay was introduced which can detect all known types of neurotropic sapelo-, tescho- and type 3 astroviruses in multiple types of samples of swine. The assay was evaluated using in vitro synthesized RNA standards and a total of 142 archived RNA samples including known sapelo-, tescho- and type 3 astrovirus positive and negative CNS, enteric and nasal specimens. The results of a large-scale epidemiological investigation of these viruses on = 473 nasal swab samples from = 28 industrial-type swine farms in Hungary indicate that all three neurotropic viruses, especially type 3 astroviruses, are widespread and endemically present on most of the investigated farms.
Topics: Animals; Astroviridae; Astroviridae Infections; Feces; Mamastrovirus; Phylogeny; Picornaviridae; RNA, Viral; Swine; Swine Diseases; Teschovirus
PubMed: 35336920
DOI: 10.3390/v14030513 -
Viruses Jun 2021Astroviruses are non-enveloped, single-stranded RNA viruses that infect mammalian and avian species. In humans, astrovirus infections are one of the most common causes... (Review)
Review
Astroviruses are non-enveloped, single-stranded RNA viruses that infect mammalian and avian species. In humans, astrovirus infections are one of the most common causes of gastroenteritis in children. Infection has also been linked to serious neurological complications, especially in immunocompromised individuals. More extensive disease has also been characterized in non-human mammalian and avian species. To date, astroviruses have been detected in over 80 different avian and mammalian hosts. As the number of hosts continues to rise, the need to understand how astroviruses transmit within a given species as well as to new host species becomes increasingly important. Here, we review the current understanding of astrovirus transmission, the factors that influence viral spread, and the potential for cross-species transmission. Additionally, we highlight the current gaps in knowledge and areas of future research that will be key to understanding astrovirus transmission and zoonotic potential.
Topics: Animals; Astroviridae; Astroviridae Infections; Birds; Gastroenteritis; Host Specificity; Humans; Phylogeny; Viral Zoonoses
PubMed: 34208242
DOI: 10.3390/v13061127