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1.
Arch Virol ; 168(2): 36, 2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36609588

RESUMO

Viral pathogens are the primary cause of canine gastroenteritis. However, few structured comprehensive studies on the viral etiology of canine gastroenteritis have been conducted. In this study, 475 rectal swabs collected over three years (2018-2021) from clinical canine gastroenteritis cases were screened for the presence of six major enteric viruses - canine parvovirus 2 (CPV-2), canine distemper virus (CDV), canine adenovirus 2 (CAdV-2), canine coronavirus (CCoV), canine astrovirus (CaAstV), and canine rotavirus (CRV) - by real-time PCR. The most frequently detected virus was CPV-2, which was present in 64.8% of the samples (subtype 2a, 21.1%; 2b, 77.4%; 2c, 1.5%), followed by CDV (8%), CaAstV (7.2%), CCoV (5.9%), and CAdV-2 (4.6%). Two to four of these viruses in different combinations were found in 16.8% of the samples, and CRV was not detected. The complete genome sequences of Indian isolates of CDV, CCoV, and CaAstV were determined for the first time, and phylogenetic analysis was performed. This study highlights the need for routine prophylactic vaccination with the appropriate vaccines. Notably, 70.3% of animals vaccinated with DHPPiL were found to be positive for at least one virus. Hence, regular molecular analysis of the prevalent viruses is crucial for addressing vaccination failures.


Assuntos
Coronavirus Canino , Vírus da Cinomose Canina , Cinomose , Doenças do Cão , Gastroenterite , Mamastrovirus , Infecções por Parvoviridae , Parvovirus Canino , Rotavirus , Animais , Cães , Filogenia , Doenças do Cão/epidemiologia , Gastroenterite/veterinária , Reação em Cadeia da Polimerase em Tempo Real , Rotavirus/genética , Coronavirus Canino/genética , Mamastrovirus/genética , Vírus da Cinomose Canina/genética
2.
Virol J ; 19(1): 221, 2022 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-36544187

RESUMO

Aim of this study was to investigate the molecular diversity of human astroviruses (HAstV) in Germany. A follow-up study was performed with human stool samples collected in 2018-2019, which were genotyped retrospectively. A total of 2645 stool samples, collected between January 2018 and December 2019 from sporadic cases and outbreaks of acute gastroenteritis were analyzed. An algorithm of PCR systems was used to characterize human astrovirus. Human astroviruses were found in 40 samples (positive rate: 1.6%). During the study period, children aged 1-2 years (48%) were most affected by HAstV. Genotyping revealed a number of nine circulating genotypes representing four human Mamastrovirus species. Strain MLB1 was predominant in the study population with a detection rate of 25% followed by HAstV1 with a positive rate of 20%. The diversity of astrovirus genotypes seems to be rather stable in Germany in the last years. A clustering of regionally and/or temporally linked human astroviruses in Germany was not detectable.


Assuntos
Infecções por Astroviridae , Mamastrovirus , Criança , Humanos , Mamastrovirus/genética , Estudos Retrospectivos , Seguimentos , Infecções por Astroviridae/epidemiologia , Fezes , Filogenia , Genótipo
3.
Structure ; 30(12): 1573-1581.e3, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36417907

RESUMO

Despite their worldwide prevalence and association with human disease, the molecular bases of human astrovirus (HAstV) infection and evolution remain poorly characterized. Here, we report the structure of the capsid protein spike of the divergent HAstV MLB clade (HAstV MLB). While the structure shares a similar folding topology with that of classical-clade HAstV spikes, it is otherwise strikingly different. We find no evidence of a conserved receptor-binding site between the MLB and classical HAstV spikes, suggesting that MLB and classical HAstVs utilize different receptors for host-cell attachment. We provide evidence for this hypothesis using a novel HAstV infection competition assay. Comparisons of the HAstV MLB spike structure with structures predicted from its sequence reveal poor matches, but template-based predictions were surprisingly accurate relative to machine-learning-based predictions. Our data provide a foundation for understanding the mechanisms of infection by diverse HAstVs and can support structure determination in similarly unstudied systems.


Assuntos
Capsídeo , Mamastrovirus , Humanos , Mamastrovirus/genética , Proteínas do Capsídeo , Sítios de Ligação , Aprendizado de Máquina
4.
Viruses ; 14(10)2022 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-36298789

RESUMO

Astroviruses (AstVs) are single-stranded RNA viruses, including two main genera: Mamastroviruses (MAstVs) and Avastroviruses (AAstVs). AstVs have been detected in more than 80 different mammals and birds, with the characteristics of multiple cross-species transmission and gene recombination. All these have accelerated the process of virus mutation and posed a potential threat to human beings and animal husbandry. Yunnan province is a global hotspot with rich biodiversity and abundant animal resources and an important area with significance for public health and security because it neighbors a few Southeast Asian countries. This study collected 860 samples from 13 species of animals in Yunnan province for AstVs detection. The results showed that the positive rate of AstVs was 6.05%, and its extremely high genetic diversity was observed in different animal species. Potential cross-species transmission events were also detected from rodents to birds. Therefore, AstVs, which are widely distributed with highly diverse genes and the risk of cross-species transmission to people, deserve more attention in this region.


Assuntos
Infecções por Astroviridae , Avastrovirus , Mamastrovirus , Animais , Humanos , Filogenia , China/epidemiologia , Mamíferos , Aves , Roedores , Variação Genética
5.
J Appl Microbiol ; 133(6): 3523-3533, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36000509

RESUMO

AIMS: To estimate the risk of human rotavirus (RV) and astrovirus (HAstV) infections for swimmers and fishers at Las Cañas beach, Uruguay. METHODS AND RESULTS: Surface water samples were collected monthly for 1 year. The dose-response models used were ß-Poisson and 1 F1 hypergeometric for RV and HAstV, respectively. The probabilities of infection were calculated using a kernel density estimate to fitting the data and then sampling from this distribution (Monte Carlo simulation). The probability of RV infection for fishers was between 0 and 65% and for swimmers was between 0 and 50% (<18 years old) and between 0 and 38% (>18 years old). For HAstV, the probability of infection for fishers was between 0% and 45% and for swimmers was between 0 and 38% (<18 years old) and between 0 and 18% (>18 years old). CONCLUSIONS: This study suggests that fishers are at higher risk of infection for both viruses compared with swimmers mainly due to higher viral frequency and concentration at the site for fishing activities.


Assuntos
Infecções por Astroviridae , Mamastrovirus , Rotavirus , Humanos , Adolescente , Rotavirus/genética , Mamastrovirus/genética , Natação , Uruguai/epidemiologia , Caça , Fezes
6.
Microb Pathog ; 170: 105703, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35934204

RESUMO

Porcine epidemic diarrhea virus (PEDV) frequently causes diarrhea outbreaks. However, whether newly discovered enteric viruses such as porcine kobuvirus (PKV) and porcine astroviruses (PAstVs) are also correlated with diarrhea is still unclear. Diarrhea outbreaks were reported in a PEDV-vaccinated pig farm in Xinjiang Uygur Autonomous Region of China from 2019 to 2020. PEDV was a common pathogen detected in fecal samples by routine RT-PCR assays. The PEDV positive fecal sample was used for pathogenic analysis due to the failure isolation of PEDV. The challenged neonatal piglets appeared watery diarrhea within one day post infection (dpi) and all died within 6 dpi. Histopathological and immunohistochemical examinations supported that PEDV is a major pathogen causing intestinal lesions. To further explore enteric viruses associated with neonatal piglet diarrhea, metagenomics sequencing was performed for the diarrheic piglets. Remarkably, PKV was the most abundant virus (58.33%) followed by PEDV (34.45%) and PAstVs (7.22%), which were also confirmed by real-time RT-PCR assays. Significant in vivo replications of PEDV and PKV could only be observed in challenged piglets whilst PAstVs maintained similar virus loads in both challenged and mock infected piglets. Overall, this study provides first pathogenic and metagenomic evidence that significant proliferations of PEDV and PKV are closely associated with severe diarrhea in neonatal piglets, while PAstVs likely play limited roles in neonatal piglet diarrhea.


Assuntos
Infecções por Coronavirus , Kobuvirus , Vírus da Diarreia Epidêmica Suína , Doenças dos Suínos , Animais , Diarreia/epidemiologia , Kobuvirus/genética , Mamastrovirus , Metagenômica , Vírus da Diarreia Epidêmica Suína/genética , Suínos
7.
Rev Med Virol ; 32(6): e2389, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36030520

RESUMO

Human astroviruses (HAstVs) have frequently been detected in individuals with acute gastroenteritis (AGE). However, a precise estimate of the overall prevalence of the virus in children with AGE as well as the possible association of the virus with gastrointestinal complications is not available up to now. The present study estimated the overall prevalence of HAstVs in children with gastrointestinal complications as well as the association between the virus and symptoms. We systematically searched four international databases (PubMed, Scopus, Web of Science, and Google scholar) to find studies on the prevalence of HAstVs in people with AGE published between Jan 2000 and Sep 2021. Analysis of the 223 included studies presented a 4.2% (95% CI 3.8%-4.8%) prevalence of the virus in AGE individuals. Based on case-control studies, a significant association between these viruses and AGE was detected (OR: 2.059, 95% CI; 1.438-2.949). HAstV-1 and HAstV-VA-2 is the most and least common genotypes in the AGE patients, respectively (59.0%, 95% CI: 52.1%-65.6% vs. 4.9%, 95% CI: 2.6%-9.1%). Due to the statistically significant association between HAstV and gastrointestinal complications, more attention should be paid to these viruses in people with AGE and more studies should employ case-control design.


Assuntos
Infecções por Astroviridae , Infecções por Enterovirus , Gastroenterite , Mamastrovirus , Criança , Humanos , Mamastrovirus/genética , Infecções por Astroviridae/complicações , Infecções por Astroviridae/epidemiologia , Infecções por Astroviridae/diagnóstico , Gastroenterite/complicações , Gastroenterite/epidemiologia , Antígenos Virais , Genótipo , Filogenia , Fezes
8.
J Pediatric Infect Dis Soc ; 11(9): 408-412, 2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-35849135

RESUMO

Novel human astroviruses (HAstVs) have recently been implicated as rare causes of fatal encephalitis in immunocompromised patients, for which there is no proven treatment. We report 2 cases from our institution in which HAstV-VA1 was detected in the cerebrospinal fluid by metagenomic next-generation sequencing after the initial evaluation revealed no etiology.


Assuntos
Infecções por Astroviridae , Encefalite , Mamastrovirus , Neoplasias , Infecções por Astroviridae/diagnóstico , Criança , Fezes , Humanos , Hospedeiro Imunocomprometido , Mamastrovirus/genética , Filogenia
9.
Viruses ; 14(7)2022 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-35891364

RESUMO

Porcine astrovirus (PAstV) has been identified as an important diarrheic pathogen with a broad global distribution. The PAstV is a potential pathogen to human beings and plays a role in public health. Until now, the divergence characteristics and pathogenesis of the PAstV are still not well known. In this study, the PAstV-4 strain PAstV/CH/2022/CM1 was isolated from the diarrheal feces of a piglet in Shanghai, which was identified to be a recombination of PAstV4/JPN (LC201612) and PAstV4/CHN (JX060808). A time tree based on the ORF2 protein of the astrovirus demonstrated that type 2-5 PAstV (PAstV-2 to 5) diverged from type 1 PAstV (PAstV-1) at a point from 1992 to 2000. To better understand the molecular basis of the virus, we sought to explore the host cell response to the PAstV/CH/2022/CM1 infection using proteomics. The results demonstrate that viral infection elicits global protein changes, and that the mitochondria seems to be a primary and an important target in viral infection. Importantly, there was crosstalk between autophagy and apoptosis, in which ATG7 might be the key mediator. In addition, the NOD-like receptor X1 (NLRX1) in the mitochondria was activated and participated in several important antiviral signaling pathways after the PAstV/CH/2022/CM1 infection, which was closely related to mitophagy. The NLRX1 may be a crucial protein for antagonizing a viral infection through autophagy, but this has yet to be validated. In conclusion, the data in this study provides more information for understanding the virus genomic characterization and the potential antiviral targets in a PAstV infection.


Assuntos
Infecções por Astroviridae , Doenças dos Suínos , Animais , Antivirais , Infecções por Astroviridae/veterinária , China , Genômica , Humanos , Mamastrovirus , Proteínas Mitocondriais , Filogenia , Proteômica , Suínos
10.
J Virol ; 96(14): e0084822, 2022 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-35762754

RESUMO

Viral gastroenteritis has a global distribution and represents a high risk for vulnerable population and children under 5 years due to acute diarrhea, fever and dehydration. Human astroviruses (HAstV) have been identified as the third most important cause of viral gastroenteritis in pediatric and immunocompromised patients. Furthermore, HAstV has been reported in biopsies taken from patients with encephalitis, meningitis and acute respiratory infection, yet it is not clear how the virus reaches these organs. In this work we have tested the possibility that the released astrovirus particles could be associated with extracellular vesicles. Comparison between vesicles purified from HAstV Yuc8 infected and mock-infected cells showed that infection enhances production of vesicles larger than 150 nm. These vesicles contain CD63 and Alix, two markers of vesicular structures. Almost 70% of the extracellular virus present in clarified supernatant at 18 h postinfection was found associated with vesicular membranes, and this association facilitates cell infection in the absence of trypsin activation and protects virions from neutralizing antibodies. Our findings suggest a new pathway for HAstV spread and might represent an explanation for the extra-intestinal presence of some astrovirus strains. IMPORTANCE Astroviruses are an important cause of diarrhea in vulnerable population, particularly children; recently some reports have found these viruses in extra-intestinal organs, including the central nervous system, causing unexpected clinical disease. In this work, we found that human astrovirus strain Yuc8 associates with extracellular vesicles, possibly during or after their cell egress. The association with vesicles doubled astrovirus infectivity in less susceptible cells and rendered virus particles insensitive to neutralization by antibodies. These data suggest that extracellular vesicles could represent a novel pathway for astrovirus to disseminate outside the gastrointestinal tract.


Assuntos
Infecções por Astroviridae , Vesículas Extracelulares , Gastroenterite , Mamastrovirus , Anticorpos Neutralizantes , Infecções por Astroviridae/imunologia , Infecções por Astroviridae/virologia , Vesículas Extracelulares/virologia , Gastroenterite/virologia , Humanos , Mamastrovirus/imunologia
11.
J Virol ; 96(14): e0066522, 2022 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-35762760

RESUMO

Human astrovirus VA1 has been associated with neurological disease in immunocompromised patients, and its recent propagation in cell culture has opened the possibility to study its biology. Unlike classical human astroviruses, VA1 growth was found to be independent of trypsin during virus replication in vitro. In this work, we show that despite its independence on trypsin activation for cell infection, the VA1 capsid precursor protein, of 86 kDa (VP86), is processed intracellularly, and this proteolytic processing is important for astrovirus VA1 infectivity. Antibodies raised against different regions of the capsid precursor showed that the polyprotein can be processed starting at either its amino- or carboxy-terminal end, and they allowed us to identify those proteins of about 33 (VP33) and 38 (VP38) kDa constitute the core and the spike proteins of the mature infectious virus particles, respectively. The amino-terminal end of the spike protein was found to be Thr-348. Whether the protease involved in intracellular cleavage of the capsid precursor is of viral or cellular origin remains to be determined, but the cleavage is independent of caspases. Also, trypsin is able to degrade the capsid precursor but has no effect on VP33 and VP38 proteins when assembled into virus particles. These studies provide the basis for advancement of the knowledge of astrovirus VA1 cell entry and replication. IMPORTANCE Human astrovirus VA1 has been associated with neurological disease in immunocompromised patients. Its recent propagation in cell culture has facilitated the study of its biology. In this work, we show that despite the ability of this virus to grow in the absence of trypsin, a marked feature of human classical astroviruses, the capsid precursor protein of astrovirus VA1 is cleaved intracellularly to yield the mature infectious particles, formed by two polypeptides, VP33 that constitutes the core domain of the virus particle, and VP38 that forms the spike of the virus. These studies provide a platform to advance our knowledge on astrovirus VA1 cell entry and replication.


Assuntos
Infecções por Astroviridae , Proteínas do Capsídeo , Mamastrovirus , Precursores de Proteínas , Infecções por Astroviridae/virologia , Células CACO-2 , Capsídeo/metabolismo , Proteínas do Capsídeo/metabolismo , Humanos , Espaço Intracelular/virologia , Mamastrovirus/fisiologia , Precursores de Proteínas/metabolismo , Tripsina/metabolismo
12.
Water Res ; 218: 118523, 2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35525029

RESUMO

Human astrovirus (HAstV) composes of classic HAstV serotypes 1-8 and recently discovered novel HAstV-MLB and HAstV-VA strains. A number of studies have demonstrated that wastewater analysis is an effective approach to understand the prevalence and diversity of enteric viruses in local population. However, a comprehensive analysis of classic and novel HAstVs in sewage is still lacking. In this study, sewage samples were collected monthly from Jinan, China during 2018-2019. Quantification of HAstV genomes was performed by real-time quantitative PCR. Different from previous studies which focused on partial ORF1b or ORF2 gene, complete ORF2 region of HAstV was amplified from sewage concentrates, and amplicons were subjected to next generation sequencing (NGS) and genetic analysis. This methodology allowed detection of 18 astroviruses, of which 7 (HAstV-1, -2, -4, -5, VA1, VA2, and VA3) were detected in all sewage samples. A new strain VA6 mapped to the HMO clade was identified in 20.8% of samples, with 82.4%-83.3% nucleotide identities to the closest strain VA5. The viral load of classic, MLB and VA clades in sewage samples ranged from 3.7 × 104 to 4.6 × 107, 3.4 × 104 to 3.9 × 106, and 3.3 × 104 to 4.1 × 106 copies per liter, respectively. Phylogenetic analysis based on complete ORF2 region reflected local HAstVs within each genotype constituted multiple co-circulating lineages. Existence of several new lineages composed exclusively or predominantly of Chinese sequences was observed as well. These results demonstrate sewage contains astroviruses with considerable high diversities. NGS based environmental surveillance greatly improves the understanding of HAstV circulation and should be encouraged.


Assuntos
Infecções por Astroviridae , Mamastrovirus , Infecções por Astroviridae/epidemiologia , Fezes , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mamastrovirus/genética , Filogenia , Esgotos
14.
PLoS Pathog ; 18(4): e1009716, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35452499

RESUMO

Human astroviruses (HAstV), positive sense single-stranded RNA viruses, are one of the leading causes of diarrhea worldwide. Despite their high prevalence, the cellular mechanisms of astrovirus pathogenesis remain ill-defined. Previous studies showed HAstV increased epithelial barrier permeability by causing a re-localization of the tight junction protein, occludin. In these studies, we demonstrate that HAstV replication induces epithelial-mesenchymal transition (EMT), by upregulating the transcription of EMT-related genes within 8 hours post-infection (hpi), followed by the loss of cell-cell contacts and disruption of polarity by 24 hpi. While multiple classical HAstV serotypes, including clinical isolates, induce EMT, the non-classical genotype HAstV-VA1 and two strains of reovirus are incapable of inducing EMT. Unlike the re-localization of tight junction proteins, HAstV-induced EMT requires productive replication and is dependent transforming growth factor-ß (TGF-ß) activity. Finally, inhibiting TGF-ß signaling and EMT reduces viral replication, highlighting its importance in the viral life cycle. This finding puts classical strains of HAstV-1 in an exclusive group of non-oncogenic viruses triggering EMT.


Assuntos
Infecções por Astroviridae , Mamastrovirus , Transição Epitelial-Mesenquimal , Humanos , Mamastrovirus/genética , Fator de Crescimento Transformador beta , Replicação Viral
15.
Virol J ; 19(1): 58, 2022 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-35361253

RESUMO

BACKGROUND: Astrovirus, Norovirus and Sapovirus are widely distributed viruses in humans and animals worldwide. They have frequently been associated with disease, mainly of gastroenteric nature. In dogs, these viruses have been detected both in symptomatic and asymptomatic animals, mainly of young age. METHODS: In the present epidemiologic study, we investigated the presence of canine Astrovirus (CAstV), canine Norovirus (canine NoV) and canine Sapovirus (Canine SaV) in saliva and stools of 201 domestic dogs originating from throughout Greece, based on two different molecular methods, i.e. conventional and SYBR-Green Real-time RT-PCR. The samples derived from young and adult asymptomatic and symptomatic animals. CAstV was detected in 15/201 (7.5%) and 29/201 (15%) of the examined dogs using conventional RT-PCR and SYBR-Green Real time RT-PCR, respectively. RESULTS: The prevalence of the virus was higher at healthy dogs, with a slight discrepancy of the two methods on the aspect of age (67% young dogs with the method of conventional RT-PCR, versus 52% adult positive dogs with the method of SYBR-Green Real-time RT-PCR). Canine SaV was detected in 52/201 (23%) of the dogs (mainly young and asymptomatic), with the method of SYBR-Green Real-time RT-PCR only, while canine NoV was not detected in any sample with either of the two methods applied. Sequencing of the CAstV positive samples resulted in the acquisition of one CAstV sequence. Phylogenetic analysis confirmed the results, clustering the CAstV sequence with homologous canine hosting sequences from other countries. CONCLUSIONS: CAstV and Canine SaV were proved to circulate in Greek dogs. SYBR-Green Real time RT-PCR showed greater sensitivity in the detection of these viruses. Additionally, we were able to specify the CAstV strain that circulates in Greece, through phylogenetic analysis. To our knowledge, this is the first epidemiological study of CAstV and canine SaV in dogs in Greece, as well as the first time detected in dogs from Greece.


Assuntos
Gastroenterite , Mamastrovirus , Sapovirus , Animais , Cães , Gastroenterite/diagnóstico , Gastroenterite/epidemiologia , Gastroenterite/veterinária , Grécia/epidemiologia , Filogenia , Sapovirus/genética
16.
Viruses ; 14(3)2022 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-35336920

RESUMO

Porcine sapeloviruses, teschoviruses of family Picornaviridae and type 3 porcine astroviruses of family Astroviridae 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 n = 473 nasal swab samples from n = 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.


Assuntos
Infecções por Astroviridae , Astroviridae , Picornaviridae , Doenças dos Suínos , Teschovirus , Animais , Astroviridae/genética , Infecções por Astroviridae/diagnóstico , Infecções por Astroviridae/veterinária , Fezes , Mamastrovirus , Filogenia , Picornaviridae/genética , RNA Viral/genética , Suínos , Doenças dos Suínos/diagnóstico , Teschovirus/genética
17.
Transbound Emerg Dis ; 69(2): 864-869, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33411943

RESUMO

Human astroviruses (AstVs) are usually associated with acute gastroenteritis. In recent years, atypical animal-like AstVs have been identified, but their pathogenic role in humans has not been determined. Starting from 2010, there has been a growing evidence that AstVs may also be associated with encephalitis in human and animal hosts. Some human atypical AstV strains (VA1, MLB1/MLB2) display neurotropic potential, as they have been repeatedly identified in patients with AstV-related encephalitis, chiefly in immunosuppressed individuals. In this study, a VA1-like AstV was identified from a single stool sample from an outbreak of foodborne acute gastroenteritis occurred in Italy in 2018. On genome sequencing, the virus was related to the VA1-like strain UK1 (99.3% at the nucleotide level). Similar viruses were also found to circulate in paediatric patients hospitalized with AGE in the same time span, 2018, but at low prevalence (0.75%, 3/401). Gathering epidemiological data on atypical AstVs will be useful to assess the risks posed by atypical AstV infections, chiefly in medically fragile patients.


Assuntos
Infecções por Astroviridae , Gastroenterite , Mamastrovirus , Animais , Infecções por Astroviridae/epidemiologia , Infecções por Astroviridae/patologia , Infecções por Astroviridae/veterinária , Fezes , Gastroenterite/epidemiologia , Gastroenterite/veterinária , Genótipo , Humanos , Mamastrovirus/genética , Filogenia
18.
Transbound Emerg Dis ; 69(3): 974-985, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-33900029

RESUMO

Porcine astroviruses (PoAstVs) have been reported globally and are divided into at least five distinct lineages (PoAstV1-PoAsV5). The primary objective of this review was to summarize the scientific literature about the frequency of detection, associated clinical presentations and type of samples and diagnostic tools used for the detection of porcine astroviruses. The secondary objective was to summarize the body of knowledge about the causal role in disease of PoAstVs using the Bradford Hill framework. A search was conducted using Centre for Biosciences and Agriculture International (CABI), MEDLINE, American Association of Swine Veterinarians (AASV) Swine Information Library (SIL) abstracts, swine conferences including American College of Veterinary Pathologists (ACVP) and American Association of Veterinary Laboratory Diagnosticians (AAVLD). From 168 studies identified by the search, 29 studies were eligible. Results indicated that 69% (20/29) of the literature on PoAstVs have been published between 2011 and 2018. Of 29 papers, 52% were detection studies (15 of 29) and 48% (14 of 29) were case-control studies. Seventy-two per cent (21 of 29) reported differential diagnosis and 10% (3 of 29) reported histologic lesions, out of which 67% (2 of 3) associated the detection of PoAstV3 with development of polioencephalomyelitis. PCR-based assays were the most common diagnostic tools.


Assuntos
Infecções por Astroviridae , Mamastrovirus , Doenças dos Suínos , Animais , Infecções por Astroviridae/diagnóstico , Infecções por Astroviridae/epidemiologia , Infecções por Astroviridae/veterinária , Estudos de Casos e Controles , Humanos , Filogenia , Suínos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/epidemiologia
19.
J Virol ; 96(1): e0141521, 2022 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-34613806

RESUMO

Human astrovirus is an important cause of viral gastroenteritis worldwide. Young children, the elderly, and the immunocompromised are especially at risk for contracting severe disease. However, no vaccines exist to combat human astrovirus infection. Evidence points to the importance of antibodies in protecting healthy adults from reinfection. To develop an effective subunit vaccine that broadly protects against diverse astrovirus serotypes, we must understand how neutralizing antibodies target the capsid surface at the molecular level. Here, we report the structures of the human astrovirus capsid spike domain bound to two neutralizing monoclonal antibodies. These antibodies bind two distinct conformational epitopes on the spike surface. We add to existing evidence that the human astrovirus capsid spike contains a receptor-binding domain and demonstrate that both antibodies neutralize human astrovirus by blocking virus attachment to host cells. We identify patches of conserved amino acids which overlap or border the antibody epitopes and may constitute a receptor-binding site. Our findings provide a basis for developing therapies to prevent and treat human astrovirus gastroenteritis. IMPORTANCE Human astroviruses infect nearly every person in the world during childhood and cause diarrhea, vomiting, and fever. Despite the prevalence of this virus, little is known about how antibodies block astrovirus infection. Here, we determined the crystal structures of the astrovirus capsid protein in complex with two virus-neutralizing antibodies. We show that the antibodies bind to two distinct sites on the capsid spike domain, however, both antibodies block virus attachment to human cells. Importantly, our findings support the use of the human astrovirus capsid spike as an antigen in a subunit-based vaccine to prevent astrovirus disease.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Infecções por Astroviridae/imunologia , Infecções por Astroviridae/virologia , Capsídeo/imunologia , Epitopos/imunologia , Mamastrovirus/imunologia , Sequência de Aminoácidos , Anticorpos Neutralizantes/química , Anticorpos Antivirais/química , Afinidade de Anticorpos/imunologia , Proteínas do Capsídeo/química , Proteínas do Capsídeo/imunologia , Epitopos/química , Interações Hospedeiro-Patógeno/imunologia , Humanos , Modelos Moleculares , Conformação Molecular , Ligação Proteica , Relação Estrutura-Atividade , Ligação Viral
20.
Arch Virol ; 167(2): 355-366, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34839421

RESUMO

Astroviruses (AstVs) are among the most important viruses causing diarrhea in human infants and many animals, posing a threat to public health safety and a burden on the economy. Five porcine AstV (PAstV) genotypes have been identified in various countries, including China. However, the epidemiology of PAstV in Yunnan province, China, remains unknown. In this study, 489 fecal samples from pigs in all 16 prefectures/cities of Yunnan were collected between April and August of 2020 for epidemiological investigation. The total infection rate of PAstV-2 or PAstV-5 was 39.9%, with suckling piglets having the highest infection rate (62.3%). The ORF2 genes of seven PAstV-2 and 10 PAstV-5 isolates were sequenced and phylogenetically analyzed. In addition to coinfections with PAstV-2 and PAstV-5, coinfections of PAstV with other diarrhea-inducing viruses (e.g., porcine bocavirus) were also discovered. A comparison of ORF2-encoded capsid protein sequences revealed that there were multiple insertions and deletions in the seven Yunnan PAstV-2 sequences, while point mutations, but no deletions or insertions, were found in the 10 Yunnan PAstV-5 sequences, which were very similar to the reference sequences. This is the first epidemiological investigation and genetic characterization of PAstV-2 and PAstV-5 in Yunnan province, China, demonstrating the current PAstV infection situation in Yunnan.


Assuntos
Infecções por Astroviridae , Doenças dos Suínos , Animais , Infecções por Astroviridae/epidemiologia , Infecções por Astroviridae/veterinária , China/epidemiologia , Genótipo , Mamastrovirus , Filogenia , Suínos , Doenças dos Suínos/epidemiologia
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