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1.
J Virol ; 97(8): e0080223, 2023 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-37504573

RESUMO

The human astrovirus (HAstV) is a non-enveloped, single-stranded RNA virus that is a common cause of gastroenteritis. Most non-enveloped viruses use membrane disruption to deliver the viral genome into a host cell after virus uptake. The virus-host factors that allow for HAstV cell entry are currently unknown but thought to be associated with the host-protease-mediated viral maturation. Using in vitro liposome disruption analysis, we identified a trypsin-dependent lipid disruption activity in the capsid protein of HAstV serotype 8. This function was further localized to the P1 domain of the viral capsid core, which was both necessary and sufficient for membrane disruption. Site-directed mutagenesis identified a cluster of four trypsin cleavage sites necessary to retain the lipid disruption activity, which is likely attributed to a short stretch of sequence ending at arginine 313 based on mass spectrometry of liposome-associated peptides. The membrane disruption activity was conserved across several other HAstVs, including the emerging VA2 strain, and effective against a wide range of lipid identities. This work provides key functional insight into the protease maturation process essential to HAstV infectivity and presents a method to investigate membrane penetration by non-enveloped viruses in vitro. IMPORTANCE Human astroviruses (HAstVs) are an understudied family of viruses that cause mild gastroenteritis but have recent cases associated with a more severe neural pathogenesis. Many important elements of the HAstV life cycle are not well understood, and further elucidating them can help understand the various forms of HAstV pathogenesis. In this study, we utilized an in vitro liposome-based assay to describe and characterize a previously unreported lipid disruption activity. This activity is dependent on the protease cleavage of key sites in HAstV capsid core and can be controlled by site-directed mutagenesis. Our group observed this activity in multiple strains of HAstV and in multiple lipid conditions, indicating this may be a conserved activity across the AstV family. The discovery of this function provides insight into HAstV cellular entry, pathogenesis, and a possible target for future therapeutics.


Assuntos
Infecções por Astroviridae , Gastroenterite , Mamastrovirus , Humanos , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/química , Mamastrovirus/genética , Tripsina , Lipossomos , Peptídeos/genética , Lipídeos , Filogenia
2.
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
3.
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
4.
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
5.
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
6.
Scand J Immunol ; 95(1): e13120, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34796982

RESUMO

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.


Assuntos
Infecções por Astroviridae/imunologia , Doença Celíaca/imunologia , Mucosa Intestinal/imunologia , Mamastrovirus/fisiologia , Células T de Memória/imunologia , Animais , Autoantígenos/imunologia , Glutens/imunologia , Humanos , Memória Imunológica , Especificidade de Órgãos
7.
BMC Gastroenterol ; 21(1): 455, 2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34861832

RESUMO

BACKGROUND: Human astrovirus (HAstV) and sapovirus (SaV) are common pathogens that can cause acute gastroenteritis (AGE). However, very few studies have reported the molecular epidemiology and clinical information on HAstV and SaV in China. This study aims to determine the molecular epidemiology and clinical features of HAstV and SaV in patients with AGE in Guangzhou, China. METHODS: For this study, 656 patients with AGE were enrolled. Their stool samples were screened for 15 enteropathogens using Luminex xTAG® Gastrointestinal Pathogen Panel. HAstV and SaV were detected through an in-house multiplex reverse transcriptase polymerase chain reaction followed by phylogenetic analysis. We described and compared clinical features of AGE in patients with HAstV and SaV. RESULTS: Of the 656 stool samples, 63.72% (418/656) were found to be positive, with 550 enteropathogens (296 bacteria and 254 viruses). HAstV and SaV were detected in 20 (3.0%) and 12 (1.8%) samples, respectively. Four genotypes (genotypes 1, 2, 3, and 8) of HAstV and three genotypes (GI.1, GI.2 and GIV) of SaV were identified. Coinfection was observed in ten HAstV-positive and two SaV-positive samples. HAstV was more likely to occur in winter, while SaV in early spring. The median age of the patients with single HAstV infection was higher than that of the patients with other viruses (rotavirus, norovirus, and enteric adenovirus; P = 0.0476) and unknown etiology (P = 0.006). Coinfection with HAstV or SaV were not associated with disease severity (P > 0.05). CONCLUSION: HAstV and SaV are the common causes of AGE in Guangzhou, China.


Assuntos
Gastroenterite , Mamastrovirus , Sapovirus , Fezes , Gastroenterite/epidemiologia , Genótipo , Humanos , Lactente , Mamastrovirus/genética , Pacientes Ambulatoriais , Filogenia , Sapovirus/genética
8.
Int J Biol Macromol ; 189: 939-947, 2021 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-34464644

RESUMO

Porcine astrovirus (PAstV) is prevalent in pigs worldwide and could cause clinical symptoms such as diarrhea and encephalitis. The capsid protein (Cap) of PAstV plays a determinant role for virus immunological characteristics. In this study, the major antigenic regions of PAstV1 Cap were expressed through prokaryotic expression systems and immunized to BALB/c mice. Finally, two anti-Cap monoclonal antibodies (named mAb F4-4 and D3F10) were screened by indirect immune-fluorescence assay (IFA). A series of truncated GST-fused or artificially synthesized peptides were used to detect their reactivity with the mAbs and PAstV positive serum. Two novel B cell epitopes (120-GNNTFG-125, 485-RISDPTWFSA-494) were identified by using these two mAbs. Moreover, sequence alignment result showed that epitope 120-GNNTFG-125 was highly conserved in type 1 PAstV capsid protein. Cross-reactivity analysis further confirmed the genotype-specificity of mAb F4-4. The results of this study demonstrated to be the first description of monoclonal antibody preparation and B-cell epitope mapping on PAstV capsid protein, which may provide new information on the biological significance of PAstV capsid protein and lay a foundation for the development of PAstV immunological tests and genotype diagnostic methods.


Assuntos
Anticorpos Monoclonais/metabolismo , Proteínas do Capsídeo/imunologia , Epitopos de Linfócito B/imunologia , Mamastrovirus/imunologia , Sequência de Aminoácidos , Animais , Proteínas do Capsídeo/química , Reações Cruzadas/imunologia , Feminino , Camundongos Endogâmicos BALB C , Modelos Moleculares , Peptídeos/síntese química , Peptídeos/química
9.
BMC Infect Dis ; 21(1): 713, 2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34325664

RESUMO

BACKGROUND: In addition to rotavirus and norovirus, human adenovirus (HAdV) and classic human astrovirus (classic HAstV) are important pathogens of acute diarrhea in infants and young children. Here, we present the molecular epidemiology of HAdV and classic HAstV in children with acute diarrhea in Shanghai. METHODS: Fecal specimens were collected from 804 outpatient infants and young children diagnosed with acute diarrhea in Shanghai from January 2017 to December 2018. All of the samples were screened for the presence of HAdV and classic HAstV. HAdV and classic HAstV were detected using traditional PCR and reverse-transcription PCR, respectively. All of the HAdV and classic HAstV positive samples were genotyped by phylogenetic analysis. RESULTS: Among the 804 fecal samples, 8.58% (69/804) of samples were infected with either HAdV or classic HAstV, and five were co-infected with two diarrhea viruses. The overall detection rates of HAdV and classic HAstV were 3.47% (28/804) and 5.22% (42/804), respectively. Four subgroups (A, B, C, and F) and seven genotypes (HAdV-C1, -C2, -B3, -C5, -A31, -F40, and -F41) of HAdV were detected. Subgroup F had the highest constituent ratio at 64.29% (18/28), followed by non-enteric HAdV of subgroup C (21.43%, 6/28) and subgroup B 10.71% (3/28). HAdV-F41 (60.71%, 17/28) was the dominant genotype, followed by HAdV-C2 (14.29%, 4/28) and HAdV-B3 (10.71%, 3/28). Two genotypes of classic HAstV (HAstV-1 and HAstV-5) were identified in 42 samples during the study period; HAstV-1 (95.24%, 40/42) was the predominant genotype, and the other two strains were genotyped as HAstV-5. No significant differences were found between boys and girls in the detection rates of HAdV (P = 0.604) and classic HAstV (P = 0.275). Over half of the HAdV infections (82.14%, 23/28) and classic HAstV infections (66.67%, 28/42) occurred in children less than 36 months. Seasonal preferences of HAdV and classic HAstV infections were summer and winter, respectively. In this study, the common clinical symptoms of children with acute diarrhea were diarrhea, vomiting, fever and abdominal pain. CONCLUSIONS: Our findings indicate that HAdV and classic HAstV play important roles in the pathogenesis of acute diarrhea in children in Shanghai. Systematic and long-term surveillance of HAdV and classic HAstV are needed to monitor their prevalence in children and prevent major outbreak.


Assuntos
Adenovírus Humanos , Gastroenterite , Mamastrovirus , Adenovírus Humanos/genética , Criança , Pré-Escolar , China/epidemiologia , Diarreia/epidemiologia , Fezes , Feminino , Genótipo , Humanos , Lactente , Masculino , Mamastrovirus/genética , Filogenia , Prevalência
10.
BMC Infect Dis ; 21(1): 9, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33407180

RESUMO

BACKGROUND: To determine the prevalence of enteric infections in Aboriginal children aged 0-2 years using conventional and molecular diagnostic techniques and to explore associations between the presence of pathogens and child growth. METHODS: Cross-sectional analysis of Aboriginal children (n = 62) residing in a remote community in Northern Australia, conducted from July 24th - October 30th 2017. Stool samples were analysed for organisms by microscopy (directly in the field and following fixation and storage in sodium-acetate formalin), and by qualitative PCR for viruses, bacteria and parasites and serology for Strongyloides-specific IgG. Child growth (height and weight) was measured and z scores calculated according to WHO growth standards. RESULTS: Nearly 60% of children had evidence for at least one enteric pathogen in their stool (37/62). The highest burden of infection was with adenovirus/sapovirus (22.9%), followed by astrovirus (9.8%) and Cryptosporidium hominis/parvum (8.2%). Non-pathogenic organisms were detected in 22.5% of children. Ten percent of children had diarrhea at the time of stool collection. Infection with two or more pathogens was negatively associated with height for age z scores (- 1.34, 95% CI - 2.61 to - 0.07), as was carriage of the non-pathogen Blastocystis hominis (- 2.05, 95% CI - 3.55 to - 0.54). CONCLUSIONS: Infants and toddlers living in this remote Northern Australian Aboriginal community had a high burden of enteric pathogens and non-pathogens. The association between carriage of pathogens/non-pathogens with impaired child growth in the critical first 1000 days of life has implications for healthy child growth and development and warrants further investigation. These findings have relevance for many other First Nations Communities that face many of the same challenges with regard to poverty, infections, and malnutrition.


Assuntos
Infecções por Adenovirus Humanos/epidemiologia , Adenovírus Humanos/genética , Infecções por Astroviridae/epidemiologia , Infecções por Caliciviridae/epidemiologia , Criptosporidiose/epidemiologia , Cryptosporidium/genética , Gastroenterite/epidemiologia , Mamastrovirus/genética , Sapovirus/genética , Infecções por Adenovirus Humanos/virologia , Adenovírus Humanos/isolamento & purificação , Animais , Infecções por Astroviridae/virologia , Austrália/epidemiologia , Infecções por Caliciviridae/virologia , Pré-Escolar , Estudos Transversais , Criptosporidiose/parasitologia , Cryptosporidium/isolamento & purificação , Diarreia/epidemiologia , Diarreia/parasitologia , Diarreia/virologia , Fezes/parasitologia , Fezes/virologia , Feminino , Gastroenterite/parasitologia , Gastroenterite/virologia , Humanos , Lactente , Recém-Nascido , Masculino , Mamastrovirus/isolamento & purificação , Havaiano Nativo ou Outro Ilhéu do Pacífico , Reação em Cadeia da Polimerase/métodos , Prevalência , Sapovirus/isolamento & purificação
11.
Braz. j. infect. dis ; 24(6): 575-579, Nov.-Dec. 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1153500

RESUMO

ABSTRACT Human astrovirus (HAstV) 1-8 and highly divergent HAstVMLB1−3 genotypes have been detected in children both with and without acute gastroenteritis (AGE). One hundred and seventy fecal samples from children (≤5 years old) living in the Amazon region were evaluated for the presence of HAstV1-8, HAstV MLB1−3 and HAstVVA1−3, using an usual RT-PCR protocol and a new protocol with specific primers designed to detect HAstVMLB1−3. HAstVMLB1 and HAstV MLB2, as well as the HAstV3 and 5 genotypes were detected. HAstVMLB1−2 genotype was detected for the first time in Brazil at a frequency of 3.5% (6/170).


Assuntos
Criança , Humanos , Lactente , Mamastrovirus , Infecções por Astroviridae , Gastroenterite , Filogenia , Mamastrovirus/genética , Brasil , Infecções por Astroviridae/diagnóstico , Infecções por Astroviridae/epidemiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fezes , Gastroenterite/diagnóstico , Genótipo
12.
Virus Genes ; 56(6): 696-704, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32880793

RESUMO

Neonatal diarrhea in piglets may cause major losses in affected pig herds. The present study used random high-throughput RNA sequencing (metagenomic next generation sequencing, mNGS) to investigate the virome of sows from a farm with persistent neonatal piglet diarrhea in comparison to two control farms without diarrhea problems. A variety of known swine gastrointestinal viruses was detected in the control farms as well as in the problem farm (Mamastrovirus, Enterovirus, Picobirnavirus, Posavirus 1, Kobuvirus, Proprismacovirus). A substantial increase in normalized viral read counts was observed in the affected farm compared to the control farms. The increase was attributable to a single viral species in each of the sampled sows (porcine astrovirus 4 and Posavirus 1). The complete genomes of a porcine astrovirus 4 and two co-infecting Posavirus 1 were de novo assembled and characterized. The 6734 nt single-stranded RNA genome of porcine astrovirus 4 (PoAstV-4) strain Belgium/2019 contains three overlapping open reading frames (nonstructural protein 1ab, nonstructural protein 1a, capsid protein). Posavirus 1 strains Belgium/01/2019 and Belgium/02/2019 have a 9814 nt single-stranded positive-sense RNA genome encoding a single open reading frame (polyprotein precursor) containing the five expected Picornavirales-conserved protein domains. The study highlights the potential of mNGS workflows to study unexplained neonatal diarrhea in piglets and contributes to the scarce availability of both PoAstV-4 and Posavirus-1 whole genome sequences from Western Europe.


Assuntos
Diarreia , Genoma Viral , Mamastrovirus/genética , Picornaviridae/genética , Doenças dos Suínos/virologia , Animais , Diarreia/veterinária , Diarreia/virologia , Fezes/virologia , Metagenoma , Suínos
13.
Virus Res ; 288: 198138, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32827625

RESUMO

Human astroviruses (HAstVs) were first identified in 1975 and can be classified into three clades: classic HAstVs (HAstV 1-8), MLB (MLB1-3) and VA (VA1-5), with MLB and VA were newly identified. Recombination and a high mutation rate make HAstV as one of the rapidly evolving infectious agents. This study reported a novel identified recombinant human astrovirus (Y/1-CHN) and its long existence in two immunocompromised patients with diarrhea following allogeneic hematopoietic stem cell transplantation (allo-HSCT). The identified Yu/1-CHN genome contains 6801 base pairs encoding three open reading frames, with ORF1a best hit to the HAstV1 (Pune strain, 97 % nucleotide identity), while ORF1b and ORF2 best hit to HAstV-5 (DL30 strain, 99 % nucleotide identity). Possible recombination breakpoint was predicted to be located in the boundary of ORF1a and ORF1b. Different quasispecies were found in the host, and the dN/dS ratios of the S and P domains were determined to be 1.189 and 1.444, respectively, suggesting a positive selection existed. Fecal samples collected in different clinical phases from the two patients were all positive for Yu/1-CHN, suggesting a long existence of the virus in the host. It was indicated that immunocompromised patients may a reservoir for astrovirus, their excreta should be monitored even after discharge from hospital.


Assuntos
Infecções por Astroviridae/virologia , Genoma Viral , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Mamastrovirus/genética , Mamastrovirus/isolamento & purificação , Quase-Espécies/genética , Reservatórios de Doenças/virologia , Fezes/virologia , Variação Genética , Humanos , Hospedeiro Imunocomprometido , Mamastrovirus/classificação , Filogenia
14.
Artigo em Inglês | MEDLINE | ID: mdl-32586945

RESUMO

OBJECTIVE: To estimate the number of deaths from foodborne disease in the UK from 11 key pathogens. DESIGN: Four different models were developed using data from a range of sources. These included enhanced surveillance, outbreaks, death certificates and hospital episode statistics data. For each model, median estimates were produced with 95% credible intervals (CrI). The results from the different models were compared. RESULTS: The estimates for foodborne deaths for each pathogen from the different models were consistent, with CrIs largely overlapping. Based on the preferred model for each pathogen, foodborne norovirus is estimated to cause 56 deaths per year (95% CrI 32 to 92), foodborne Salmonella 33 deaths (95% CrI 7 to 159), foodborne Listeria monocytogenes 26 deaths (95% CrI 24 to 28), foodborne Clostridium perfringens 25 deaths (95% CrI 1 to 163) and foodborne Campylobacter 21 deaths (95% CrI 8 to 47). The considerable overlap in the CrIs means it is not possible to make any firm conclusions on ranking. Most of these deaths occur in those aged over 75 years. Foodborne deaths from Shigella, Cryptosporidium, Giardia, adenovirus, astrovirus and rotavirus are all rare. CONCLUSIONS: We estimate that there are 180 deaths per year in the UK (95% CrI 113 to 359) caused by foodborne disease based on these 11 pathogens. While this is a small fraction of the estimated 2.4 million cases of foodborne illness per year it still illustrates the potential severity of these illnesses demonstrating the importance in continuing efforts to reduce these infections.


Assuntos
Surtos de Doenças/estatística & dados numéricos , Doenças Transmitidas por Alimentos/epidemiologia , Mortalidade/tendências , Vigilância da População/métodos , Adenoviridae/isolamento & purificação , Idoso , Idoso de 80 Anos ou mais , Campylobacter/isolamento & purificação , Clostridium perfringens/isolamento & purificação , Cryptosporidium/isolamento & purificação , Atestado de Óbito , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/parasitologia , Doenças Transmitidas por Alimentos/virologia , Giardia/isolamento & purificação , Humanos , Listeria monocytogenes/isolamento & purificação , Mamastrovirus/isolamento & purificação , Norovirus/isolamento & purificação , Rotavirus/isolamento & purificação , Salmonella/isolamento & purificação , Índice de Gravidade de Doença , Shigella/isolamento & purificação , Reino Unido/epidemiologia
15.
Sci Rep ; 10(1): 1760, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-32020041

RESUMO

Novel human astroviruses (HAstV) were discovered 10 years ago and have been associated with fatal cases of central nervous system infections. Their role in gastroenteritis is controversial, as they have been identified in symptomatic and asymptomatic subjects. The aim of the study was to investigate novel HAstV in a gastroenteritis case-control study including a pediatric population in Spain over a one-year period. We included stool samples from patients with gastroenteritis and negative results for viruses screened by routine diagnostics, and stool samples of control subjects who sought for a routine medical consultation. All samples were screened by real-time RT-PCR assays for novel HAstV. An additional screening for rotavirus, norovirus GI, GII, sapovirus, classic HAstV and adenovirus was also performed for the control group. Overall, 23/363 stool samples from case patients (6.3%) and 8/199 stool samples from control patients (4%) were positive for ≥1 novel HAstV. MLB1 was predominant (64.5% of positives). Seasonality was observed for the case group (p = 0.015), but not the control group (p = 0.95). No difference was observed in the prevalence of novel HAstV between the case and control groups (OR 1.78, 95% CI 0.68-5.45; p = 0.30). Nevertheless, MLB genome copy numbers/ml of fecal suspension was significantly higher in the control group than in the case group (p = 0.008). In our study, we identified a lack of association between novel HAstV and gastroenteritis in the studied population, which could indicate a potential role of reservoir for children, especially given the higher viral load observed in the asymptomatic group for some of them.


Assuntos
Infecções por Astroviridae/virologia , Diarreia/virologia , Genes Virais/genética , Mamastrovirus/genética , Estudos de Casos e Controles , Criança , Pré-Escolar , Diarreia/etiologia , Fezes/virologia , Feminino , Gastroenterite/etiologia , Gastroenterite/virologia , Dosagem de Genes/genética , Variação Genética/genética , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Filogenia , Prevalência , Espanha , Carga Viral/genética
16.
Diagn Microbiol Infect Dis ; 96(2): 114924, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31757559

RESUMO

Sapovirus (SaV) and astrovirus (AstV) increasingly are recognized as cause of acute viral gastroenteritis (AGE). We evaluated the real-time RT-PCR assays RIDA®GENE SaV and viral stool panel II (RGN RT-PCR) for detection of SaV, AstV, adenovirus (AdV) F40/41 and rotavirus (RoV) in clinical stool samples (n = 69). Results were compared with reference singleplex RT-PCRs. The sensitivity for SaV, AstV and RoV are 100%, the specificity ranges from 98.1% to 100%. In 10 out of 11 AdV (all types) samples, the RGN RT-PCR for AdV F40/41 displayed negative results. Retrospectively, 196 stool specimens from adult patients previously tested negative for norovirus (NoV) were analyzed. In about 10% of NoV-negative stool samples, AdV (n = 9), RoV (n = 6), AstV (n = 3) or SaV (n = 3) were found. The RGN RT-PCR assays are useful for detection of enteric viruses other than NoV. This study emphasizes the need for further testing of NoV-negative stool samples in patients with AGE.


Assuntos
Adenoviridae/genética , Fezes/virologia , Gastroenterite/diagnóstico , Gastroenterite/virologia , Mamastrovirus/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Rotavirus/genética , Sapovirus/genética , Adenoviridae/classificação , Adenoviridae/isolamento & purificação , Adulto , Feminino , Humanos , Masculino , Mamastrovirus/classificação , Mamastrovirus/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/normas , Reprodutibilidade dos Testes , Rotavirus/classificação , Rotavirus/isolamento & purificação , Sapovirus/classificação , Sapovirus/isolamento & purificação , Sensibilidade e Especificidade , Suíça
17.
J Clin Virol ; 123: 104247, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31864069

RESUMO

BACKGROUND: Recent recognition of invasive astrovirus infections, including encephalitis and viremia in humans, have highlighted the need for effective anti-astrovirus therapeutics. However, there is a paucity of data regarding the in vitro activity of broad-spectrum RNA antivirals against astroviruses, including ribavirin and favipiravir. OBJECTIVES: We quantified the EC50 values for ribavirin and favipiravir against two human astrovirus strains, astrovirus VA1 (VA1) and human astrovirus 4 (HAstV4). STUDY DESIGN: Caco-2 cells were infected with VA1 or HAstV4 in the presence of ribavirin or favipiravir (dose range 0.1-1000 µM), and the cells were maintained in media containing the drugs for 72 h. Viral RNA was extracted and quantified by qRT-PCR. As a surrogate for cytotoxicity, cellular adenosine triphosphate (ATP) from each drug treatment was also measured. RESULTS: VA1 replication was inhibited 10-100-fold by both ribavirin (EC50 = 154 µM) and favipiravir (EC50 = 246 µM). In contrast, ribavirin inhibited HAstV4 replication (EC50 = 268 µM) but favipiravir only reduced replication by 44% at the highest dose. Mild reductions in ATP (17-31%) was only observed at the highest concentration of ribavirin (1000 µM) and no significant decrease in ATP was detected for any concentration of favipiravir. CONCLUSIONS: Ribavirin inhibited both human astrovirus species and favipiravir was only active against VA1. In the future, the in vivo efficacy of these drugs could be tested with development of an animal model of human astrovirus infection.


Assuntos
Amidas/farmacologia , Antivirais/farmacologia , Mamastrovirus/efeitos dos fármacos , Pirazinas/farmacologia , Ribavirina/farmacologia , Replicação Viral/efeitos dos fármacos , Células CACO-2 , Humanos , Mamastrovirus/fisiologia
18.
PLoS Pathog ; 15(10): e1008057, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31671153

RESUMO

Human astroviruses (HAstV) are understudied positive-strand RNA viruses that cause gastroenteritis mostly in children and the elderly. Three clades of astroviruses, classic, MLB-type and VA-type have been reported in humans. One limitation towards a better understanding of these viruses has been the lack of a physiologically relevant cell culture model that supports growth of all clades of HAstV. Herein, we demonstrate infection of HAstV strains belonging to all three clades in epithelium-only human intestinal enteroids (HIE) isolated from biopsy-derived intestinal crypts. A detailed investigation of infection of VA1, a member of the non-canonical HAstV-VA/HMO clade, showed robust replication in HIE derived from different patients and from different intestinal regions independent of the cellular differentiation status. Flow cytometry and immunofluorescence analysis revealed that VA1 infects several cell types, including intestinal progenitor cells and mature enterocytes, in HIE cultures. RNA profiling of VA1-infected HIE uncovered that the host response to infection is dominated by interferon (IFN)-mediated innate immune responses. A comparison of the antiviral host response in non-transformed HIE and transformed human colon carcinoma Caco-2 cells highlighted significant differences between these cells, including an increased magnitude of the response in HIE. Additional studies confirmed the sensitivity of VA1 to exogenous IFNs, and indicated that the endogenous IFN response of HIE to curtail the growth of strains from all three clades. Genotypic variation in the permissiveness of different HIE lines to HAstV could be overcome by pharmacologic inhibition of JAK/STAT signaling. Collectively, our data identify HIE as a universal infection model for HAstV and an improved model of the intestinal epithelium to investigate enteric virus-host interactions.


Assuntos
Infecções por Astroviridae/imunologia , Infecções por Astroviridae/veterinária , Mucosa Intestinal/imunologia , Intestino Delgado/imunologia , Mamastrovirus/fisiologia , Tropismo Viral/genética , Animais , Células CACO-2 , Linhagem Celular , Chlorocebus aethiops , Enterócitos/virologia , Gastroenterite/virologia , Humanos , Imunidade Inata/imunologia , Interferons/imunologia , Mucosa Intestinal/citologia , Mucosa Intestinal/virologia , Intestino Delgado/citologia , Intestino Delgado/virologia , Mamastrovirus/genética , Mamastrovirus/imunologia , Células Vero , Tropismo Viral/imunologia
19.
Minerva Pediatr ; 71(5): 431-437, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31660711

RESUMO

BACKGROUND: Viral gastroenteritides are among the causes of higher morbidity and mortality in the childhood period, especially in infants. Although viral-induced diarrheal diseases are important problems in Erzurum, there have been no studies on the molecular prevalence of viral gastroenteritis agents in this region's children. The aim of the prospective study is to determine the molecular prevalence of the most commonly seen viral etiologic agents and their coinfection rates in children under 5 years of age with gastroenteritis in Erzurum, Turkey. METHODS: Stool samples from 375 children between 0 and 5 years of age who suffered from acute diarrhea were investigated for the presence of Rotavirus, Norovirus, Astrovirus and Adenovirus by reverse transcriptase polymerase chain reaction, followed by conventional PCR techniques. The presence of Rotavirus, Norovirus, Astrovirus and Adenovirus in the specimens was detected by amplification of the VP6, RdRp, ORF-1b and Hexon regions, respectively. Stool samples were also investigated non-viral enteropathogens by conventional techniques. RESULTS: At least one viral pathogen was detected in 59.2% of the stool samples. Rotavirus was the most frequently observed agent (32.3%), followed by Norovirus (20.3%), Adenovirus (9.6%) and Astrovirus (5.6%). All specimens were negative for bacterial pathogens. Twenty seven (7.2%) specimens were positive for intestinal helminths and protozoan. A total of 39 coinfection (10.4%) including 38 dual and 1 triple were detected. The most frequent coinfections were observed between Norovirus plus Rotavirus and Norovirus plus Adenovirus. CONCLUSIONS: Single infections or coinfections of the enteropathogenic viruses occur at a significant rate in Erzurum's children. This study draws attention to the necessity of taking account of multiple viral infections in studies on combined vaccines and the treatment of gastroenteritis.


Assuntos
Infecções por Adenoviridae/epidemiologia , Infecções por Astroviridae/epidemiologia , Infecções por Caliciviridae/epidemiologia , Gastroenterite/epidemiologia , Infecções por Rotavirus/epidemiologia , Adenoviridae/isolamento & purificação , Pré-Escolar , Coinfecção , Diarreia/epidemiologia , Diarreia/virologia , Fezes/virologia , Gastroenterite/virologia , Humanos , Lactente , Recém-Nascido , Mamastrovirus/isolamento & purificação , Norovirus/isolamento & purificação , Prevalência , Estudos Prospectivos , Rotavirus/isolamento & purificação , Turquia/epidemiologia
20.
Arch Virol ; 164(12): 2985-2993, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31570995

RESUMO

Human adenovirus (HAdV) and human astrovirus (HAstV) are common causes of gastroenteritis. Data on the prevalence and diversity of enteric viruses are important for control and preventive measures. However, epidemiological information regarding HAdV and HAstV infections in Ethiopia are limited. Fecal specimens were collected from 450 outpatient diarrheic infants and young children in Gondar and Bahir Dar from November 2015 to April 2016. Socio-demographic information was recorded. All fecal specimens were screened for the presence of HAdV and classical HAstV using PCR. Genotyping was performed by sequencing and phylogenetic analysis. Human HAdV and HAstV were detected in 144 (32%) and 16 (3.6%) of the children, respectively. Overall, 182 different adenovirus genotypes were detected, including mixed infections. Species F adenoviruses (HAdV-40, HAdV-41) were less common than other adenoviruses (HAdV-1, -2, -3, -5,-12, -16, -31, species D types) with a frequency of 32 versus 150, respectively. The HAstV genotypes were classified as HAstV-8 (n = 10), HAstV-1 (n = 3), HAstV-2 (n = 3), and HAstV-3 (n = 1). HAstV was detected only in Gondar. Thirty-eight coinfections HAdV and one HAstV coinfections were detected. There was no significant difference in the detection rate of HAdV and HAstV between boys and girls. The detection rates also did not differ between children from rural and urban areas. Children under 6 months of age, were less often infected with both viruses. These findings suggest that HAdV and HAstV are common in children with diarrhea in Ethiopia.


Assuntos
Infecções por Adenoviridae/virologia , Adenovírus Humanos/genética , Infecções por Astroviridae/virologia , Gastroenterite/virologia , Mamastrovirus/genética , Doença Aguda/epidemiologia , Infecções por Adenoviridae/epidemiologia , Adenovírus Humanos/classificação , Adenovírus Humanos/isolamento & purificação , Adolescente , Adulto , Infecções por Astroviridae/epidemiologia , Criança , Pré-Escolar , Etiópia/epidemiologia , Feminino , Gastroenterite/epidemiologia , Variação Genética , Genótipo , Humanos , Lactente , Masculino , Mamastrovirus/classificação , Mamastrovirus/isolamento & purificação , Pessoa de Meia-Idade , Filogenia , Adulto Jovem
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