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1.
J Gen Virol ; 101(5): 510-522, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32242791

RESUMEN

Noroviruses are recognized as the major cause of non-bacterial gastroenteritis in humans. Molecular mechanisms driving norovirus evolution are the accumulation of point mutations and recombination. Recombination can create considerable changes in a viral genome, potentially eliciting a fitness cost, which must be compensated via the adaptive capacity of a recombinant virus. We previously described replicative fitness reduction of the first in vitro generated WU20-CW1 recombinant murine norovirus, RecMNV. In this follow-up study, RecMNV's capability of replicative fitness recuperation and genetic characteristics of RecMNV progenies at early and late stages of an adaptation experiment were evaluated. Replicative fitness regain of the recombinant was demonstrated via growth kinetics and plaque size differences between viral progenies prior to and post serial in vitro passaging. Point mutations at consensus and sub-consensus population levels of early and late viral progenies were characterized via next-generation sequencing and putatively associated to fitness changes. To investigate the effect of genomic changes separately and in combination in the context of a lab-generated inter-MNV infectious virus, mutations were introduced into a recombinant WU20-CW1 cDNA for subsequent DNA-based reverse genetics recovery. We thus associated fitness loss of RecMNV to a C7245T mutation and functional VP2 (ORF3) truncation and demonstrated individual and cumulative compensatory effects of one synonymous OFR2 and two non-synonymous ORF1 consensus-level mutations acquired during successive rounds of in vitro replication. Our data provide evidence of viral adaptation in a controlled environment via genetic drift after genetic shift induced a fitness cost of an infectious recombinant norovirus.


Asunto(s)
Norovirus/genética , Replicación Viral/genética , Animales , Infecciones por Caliciviridae/virología , Línea Celular , ADN Complementario/genética , Estudios de Seguimiento , Flujo Genético , Genoma Viral/genética , Ratones , Mutación Puntual/genética , Células RAW 264.7 , ARN Viral/genética
2.
J Gen Virol ; 99(8): 970-988, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29906257

RESUMEN

Noroviruses are recognized as the major global cause of sporadic and epidemic non-bacterial gastroenteritis in humans. Molecular mechanisms driving norovirus evolution are the accumulation of point mutations and recombination. Intragenotypic recombination has long been postulated to be a driving force of GII.4 noroviruses, the predominant genotype circulating in humans for over two decades. Increasingly, emergence and re-emergence of different intragenotype recombinants have been reported. The number and types of norovirus recombinants remained undefined until the 2007 Journal of General Virology research article 'Norovirus recombination' reported an assembly of 20 hitherto unclassified intergenotypic norovirus recombinant types. In the intervening decade, a host of novel recombinants has been analysed. New recombination breakpoints have been described, in vitro and in vivo studies supplement in silico analyses, and advances have been made in analysing factors driving norovirus recombination. This work presents a timely overview of these data and focuses on important aspects of norovirus recombination and its role in norovirus molecular evolution. An overview of intergenogroup, intergenotype, intragenotype and 'obligatory' norovirus recombinants as detected via in silico methods in the field is provided, enlarging the scope of intergenotypic recombinant types to 80 in total, and notably including three intergenogroup recombinants. A recap of advances made studying norovirus recombination in the laboratory is given. Putative drivers and constraints of norovirus recombination are discussed and the potential link between recombination and norovirus zoonosis risk is examined.


Asunto(s)
Infecciones por Caliciviridae/virología , Norovirus/genética , Virus Reordenados/genética , Animales , Regulación Viral de la Expresión Génica , Genotipo , Humanos , Norovirus/clasificación
3.
Arch Virol ; 162(4): 1019-1023, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27942973

RESUMEN

In this study, we report the genetic diversity and nucleotide mutation rates of five representative regions of the murine norovirus genome during in vitro passages. The mutation rates were similar in genomic regions encompassing partial coding sequences for non-structural (NS) 1-2, NS5, NS6, NS7 proteins within open reading frame (ORF) 1. In a region encoding a portion of the major capsid protein (VP1) within ORF2 (also including the ORF4 region) and a portion of the minor structural protein (VP2), the mutation rates were estimated to be at least one order of magnitude higher. The VP2 coding region was found to have the highest mutation rate.


Asunto(s)
Infecciones por Caliciviridae/veterinaria , Variación Genética , Genoma Viral , Norovirus/genética , Enfermedades de los Roedores/virología , Proteínas no Estructurales Virales/genética , Animales , Infecciones por Caliciviridae/virología , Replicación del ADN , Secuenciación de Nucleótidos de Alto Rendimiento , Ratones , Datos de Secuencia Molecular , Mutación , Norovirus/aislamiento & purificación , Norovirus/fisiología , Sistemas de Lectura Abierta , Pase Seriado , Proteínas no Estructurales Virales/metabolismo , Replicación Viral
4.
BMC Vet Res ; 12: 28, 2016 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-26895627

RESUMEN

BACKGROUND: Perinatal infections with feline panleukopenia virus (FPV) have long been known to be associated with cerebellar hypoplasia in kittens due to productive infection of dividing neuroblasts. FPV, like other parvoviruses, requires dividing cells to replicate which explains the usual tropism of the virus for the digestive tract, lymphoid tissues and bone marrow in older animals. RESULTS: In this study, the necropsy and histopathological analyses of a series of 28 cats which died from parvovirus infection in 2013 were performed. Infections were confirmed by real time PCR and immunohistochemistry in several organs. Strikingly, while none of these cats showed cerebellar atrophy or cerebellar positive immunostaining, some of them, including one adult, showed a bright positive immunostaining for viral antigens in cerebral neurons (diencephalon). Furthermore, infected neurons were negative by immunostaining for p27(Kip1), a cell cycle regulatory protein, while neighboring, uninfected, neurons were positive, suggesting a possible re-entry of infected neurons into the mitotic cycle. Next-Generation Sequencing and PCR analyses showed that the virus infecting cat brains was FPV and presented a unique substitution in NS1 protein sequence. Given the role played by this protein in the control of cell cycle and apoptosis in other parvoviral species, it is tempting to hypothesize that a cause-to-effect between this NS1 mutation and the capacity of this FPV strain to infect neurons in adult cats might exist. CONCLUSIONS: This study provides the first evidence of infection of cerebral neurons by feline panleukopenia virus in cats, including an adult. A possible re-entry into the cell cycle by infected neurons has been observed. A mutation in the NS1 protein sequence of the FPV strain involved could be related to its unusual cellular tropism. Further research is needed to clarify this point.


Asunto(s)
Cerebro/virología , Virus de la Panleucopenia Felina/aislamiento & purificación , Panleucopenia Felina/virología , Neuronas/virología , Animales , Antígenos Virales/análisis , Gatos , ADN Viral/análisis , Femenino , Masculino
5.
Arch Virol ; 159(11): 2917-23, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24938487

RESUMEN

Herpesviruses have mainly co-evolved with their hosts for millions of years. However, bovine herpesvirus 1 (BoHV1) and related ruminant alphaherpesviruses have been reported to cross the species barrier. Bubaline herpesvirus 1 (BuHV1) is an alphaherpesvirus closely related to BoHV1 and BoHV5. According to the serological cross-relationships between ruminant alphaherpesviruses, several surveys have studied the occurrence of BoHV1-related virus infection in wild and domestic ruminant species. Recent studies in Argentina showed an increase in serological prevalence against BoHV1 related viruses in water buffaloes (Bubalus bubalis) population. The aim of this study was to investigate the presence of related ruminant alphaherpesvirus in the Argentinean water buffalo population. BuHV1 was successfully isolated from 5 out of 225 buffaloes analyzed. One isolate was obtained from nasal secretions, and the others were from vaginal swabs. The buffaloes belonged to four different farms located in northeastern Argentina. The isolates were characterized as alphaherpesvirus by direct immunofluorescence using FITC-anti-BoHV1 IgG. Restriction analysis performed with BamHI and BstEII on the complete genome showed differences between the isolates and those from BoHV1 and BoHV5 subtypes. Phylogenetic analysis on both UL27 and US6 showed similarity in tree topology. While three of the isolates grouped together with sequences of BoHV5, two other isolates clustered separately. Genetic analysis of eight concatenated sequences from all isolates and references strains showed high nucleotide sequence identity between BuHV1 and BoHV5. While three of the isolates clustered together with the BoHV5 reference strain, the last two isolates were closely related to an Australian BuHV1 strain. To our knowledge, this is the first report on the isolation and molecular characterization of BuHV1 in South America. Phylogenetic analysis suggested that two different BuHV1 lineages circulate in the Argentinean water buffalo population.


Asunto(s)
Alphaherpesvirinae/aislamiento & purificación , Búfalos/virología , Infecciones por Herpesviridae/veterinaria , Alphaherpesvirinae/clasificación , Alphaherpesvirinae/genética , Animales , Argentina , Infecciones por Herpesviridae/virología , Datos de Secuencia Molecular , Filogenia
6.
Arch Virol ; 159(10): 2717-22, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24824347

RESUMEN

By screening 104 faecal samples from asymptomatic calves in Italy, bovine norovirus RNA was detected with a prevalence rate of 10.5 % (11/104). A continuous sequence spanning the RdRp region and the 5' end of the capsid gene was generated for 7 of the 11 strains. Upon phylogenetic analysis, five strains were grouped with GIII.2 Newbury2-like viruses, and one strain was grouped with GIII.1 Jena-like noroviruses. Interestingly, one strain (80TE/IT) was genetically related to the GIII.1/Jena/80/De in the RdRp but resembled the GIII.2/Newbury2/76/UK in the capsid gene, suggesting a recombination event occurring in the ORF1/ORF2 junction region.


Asunto(s)
Proteínas de la Cápside/genética , Heterogeneidad Genética , Norovirus/clasificación , Norovirus/genética , Sistemas de Lectura Abierta/genética , Secuencia de Aminoácidos , Animales , Infecciones por Caliciviridae/epidemiología , Bovinos , Enfermedades de los Bovinos/epidemiología , Heces/virología , Variación Genética , Italia/epidemiología , Datos de Secuencia Molecular , Norovirus/aislamiento & purificación , Recombinación Genética , Proteínas Estructurales Virales/genética
7.
BMC Vet Res ; 9: 111, 2013 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-23734608

RESUMEN

BACKGROUND: Several types and subtypes of bovine herpesviruses 1 and 5 (BoHV-1 and BoHV-5) have been associated to different clinical conditions of cattle, making type/subtype differentiation essential to understand the pathogenesis and epidemiology of BoHV infections. BoHV-5 subtyping is currently carried out by BstEII restriction enzyme analysis (REA) of the complete virus genome. This method allowed the description of three subtypes, one of which is the most widespread while the remaining two have so far only been found in South America. The present work describes a multiplex PCR followed by REA for BoHV-5 subtyping. RESULTS: The method consists in the simultaneous amplification of glycoprotein B and UL54 gene fragments of 534 and 669 base pairs (bp), respectively, BstEII digestion of amplicons, separation of products in 1% agarose gels, and analysis of fragment length polymorphims. The multiplex PCR detected up to 227 BoHV-5 genome copies and 9.2 × 105 BoHV-5 genome copies when DNA was extracted from purified virus or infected tissue homogenates, respectively. The applicability of multiplex PCR-REA was demonstrated on 3 BoHV-5 reference strains. In addition, subtyping of two new isolates and seventeen previously reported ones (17 BHV-5a and 2 BHV-5b) by this method gave coincident results with those obtained with the classic BstEII REA assay. CONCLUSIONS: Multiplex PCR-REA provides a new tool for the fast and simple diagnosis and subtyping of BoHV-5.


Asunto(s)
Enfermedades de los Bovinos/virología , Encefalitis Viral/veterinaria , Infecciones por Herpesviridae/veterinaria , Herpesvirus Bovino 5/genética , Meningoencefalitis/veterinaria , Reacción en Cadena de la Polimerasa Multiplex/veterinaria , Técnica del ADN Polimorfo Amplificado Aleatorio/veterinaria , Animales , Bovinos , Enfermedades de los Bovinos/diagnóstico , Encefalitis Viral/diagnóstico , Encefalitis Viral/virología , Infecciones por Herpesviridae/diagnóstico , Infecciones por Herpesviridae/genética , Infecciones por Herpesviridae/virología , Herpesvirus Bovino 5/clasificación , Herpesvirus Bovino 5/aislamiento & purificación , Masculino , Meningoencefalitis/diagnóstico , Meningoencefalitis/virología , Reacción en Cadena de la Polimerasa Multiplex/métodos , Técnica del ADN Polimorfo Amplificado Aleatorio/métodos , Sensibilidad y Especificidad
8.
BMC Vet Res ; 8: 193, 2012 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-23072668

RESUMEN

BACKGROUND: Sapoviruses are single stranded positive sense RNA viruses belonging to the family Caliciviridae. The virus is detected in different species including the human and the porcine species as an enteric pathogen causing asymptomatic to symptomatic enteritis. In this study, we report the development of a rapid real time qRT-PCR based on SYBR Green chemistry for the diagnosis of porcine sapovirus infection in swine. RESULTS: The method allows the detection of porcine sapoviruses and the quantification of the genomic copies present in stool samples. During its development, the diagnostic tool showed good correlation compared with the gold standard conventional RT-PCR and was ten-fold more sensitive. When the method was applied to field samples, porcine noroviruses from genogroup 2 genotype 11b were also detected. The method was also applied to swine samples from the Netherlands that were positive for PoSaV infection. Phylogenetic results obtained from the samples showed that PoSaV sequences were genetically related to the currently described genogroup III, to the proposed genogroup VII and also to the MI-QW19 sequence (close to the human SaV sequences). CONCLUSIONS: A rapid, sensitive, and reliable diagnosis method was developed for porcine sapovirus diagnosis. It correlated with the gold standard conventional RT-PCR. Specificity was good apart for genogroup 2 genotype 11b porcine noroviruses. As a first line screening diagnosis method, it allows a quicker and easier decision on doubtful samples.


Asunto(s)
Infecciones por Caliciviridae/veterinaria , Gastroenteritis/veterinaria , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Sapovirus/aislamiento & purificación , Enfermedades de los Porcinos/virología , Animales , Secuencia de Bases , Infecciones por Caliciviridae/diagnóstico , Infecciones por Caliciviridae/virología , Colorantes Fluorescentes , Gastroenteritis/diagnóstico , Gastroenteritis/virología , Genoma Viral , Genotipo , Humanos , Filogenia , Reproducibilidad de los Resultados , Sapovirus/genética , Sensibilidad y Especificidad , Porcinos , Enfermedades de los Porcinos/diagnóstico
9.
BMC Vet Res ; 8: 83, 2012 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-22716217

RESUMEN

BACKGROUND: Parainfluenza virus type 3 (PIV3) was isolated from dairy buffaloes (Bubalus bubalis) naturally affected with respiratory and reproductive clinical conditions. RESULTS: Examination of nasal and vaginal swabs collected from 12 diseased buffaloes led to the isolation of three paramyxovirus isolates from two animals. Antigenic, morphological and biological characteristics of these three isolates were essentially similar to those of members of the Paramyxoviridae family. Antigenic analysis by direct immunofluorescence and cross neutralization test placed these isolates together with bovine parainfluenza virus type 3 (BPIV3). Nucleotide and amino acid phylogenetic analysis of partial matrix gene sequences of the buffalo isolates and six field BPIV3 isolates from bovines in Argentina were studied. Buffalo isolates were similar to genotype B (BPIV3b) while the six BPIV3 isolates were similar to genotypes A (BPIV3a) and C (BPIV3c). CONCLUSIONS: This is the first characterization of BPIV3 in water buffalo.According to the samples analyzed, in Argentina, the genotype B was found in buffalo and the genotypes A and C were found in cattle.


Asunto(s)
Búfalos , Virus de la Parainfluenza 3 Bovina/aislamiento & purificación , Infecciones por Respirovirus/veterinaria , Animales , Argentina/epidemiología , Secuencia de Bases , Bovinos , Femenino , Genotipo , Datos de Secuencia Molecular , Virus de la Parainfluenza 3 Bovina/clasificación , Virus de la Parainfluenza 3 Bovina/genética , Filogenia , ARN Viral/genética , Infecciones por Respirovirus/epidemiología , Infecciones por Respirovirus/virología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
10.
Transbound Emerg Dis ; 69(3): 986-996, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-33909351

RESUMEN

The aim of this review paper is to evaluate the putative susceptibilities of different free-ranging wild animal species in Belgium to SARS-CoV-2 and provide a risk assessment of SARS-CoV-2 infection in those animals. Since the onset of the COVID-19 pandemic, natural SARS-CoV-2 infections have mainly been confirmed in domestic and production animals, and in wild animals kept in captivity, although the numbers remain limited when compared to human cases. Recently, the first SARS-CoV-2 infections in presumably escaped minks found in the wild have been detected, further addressing the much-feared scenario of transmission of the virus to animals living in the wild and its consequences. Considering the most likely origin of the virus being a wild animal and the putative susceptibilities of free-ranging wild animal species to SARS-CoV-2, the risk of infection with possible establishment of the virus in these populations has to be investigated closely. The authors conclude that most attention should be given to surveillance and awareness-raising activities for SARS-CoV-2 infection in wild mustelids, bats, wild canids and felids, particularly these collected in wildlife rescue centres. People involved in frequent and close contact with wild animals should take all necessary precautionary measures to protect wild animals against exposure to the virus. More than one year after the first detection of SARS-CoV-2 in humans, the time has come to increase investments in research and surveillance activities in animals, including in free-ranging wild animals, as part of a One Health control of this pandemic. This study focussing on Belgium could be helpful for other countries with similar animal densities and ecosystems.


Asunto(s)
COVID-19 , Animales , Animales Salvajes , Bélgica/epidemiología , COVID-19/epidemiología , COVID-19/veterinaria , Ecosistema , Humanos , Pandemias , Medición de Riesgo , SARS-CoV-2
11.
J Gen Virol ; 92(Pt 6): 1398-1409, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21346032

RESUMEN

Bovine noroviruses belong to the family Caliciviridae, genus Norovirus. Two genotypes have been described and viruses genetically related to the Jena and Newbury2 strains have been classified into genotypes 1 and 2, respectively. In this study, virus-like particles (VLP) of the previously detected B309 Belgian strain, genetically related to genotype 2 bovine noroviruses, were used to investigate virus-host interactions in vitro. B309 VLP were shown to bind to several bovine cell lines. This binding was not affected by heparinase or chondroitinase treatment but was significantly inhibited by both sodium periodate, α-galactosidase, trypsin and phospholipase C treatment. Cell treatment by neuraminidase also moderately affected this binding. Taken together, these results show that, in addition to a galactosyl residue, sialic acid could also be involved in binding to susceptible cells. In addition, both the cholesterol-dependent pathway and macropinocytosis are used for B309 VLP internalization by Madin-Darby bovine kidney cells. The data increase the knowledge on bovine norovirus cell interactions.


Asunto(s)
Infecciones por Caliciviridae/veterinaria , Enfermedades de los Bovinos/virología , Norovirus/fisiología , Proteínas Virales/metabolismo , Internalización del Virus , Animales , Infecciones por Caliciviridae/virología , Bovinos , Línea Celular , Interacciones Huésped-Patógeno , Datos de Secuencia Molecular , Norovirus/clasificación , Norovirus/genética , Norovirus/aislamiento & purificación , Filogenia , Unión Proteica , Spodoptera , Proteínas Virales/genética
12.
Viruses ; 13(8)2021 08 04.
Artículo en Inglés | MEDLINE | ID: mdl-34452406

RESUMEN

Human noroviruses are recognised as the major global cause of viral gastroenteritis. Here, we provide an overview of notable advances in norovirus research and provide a short recap of the novel model systems to which much of the recent progress is owed. Significant advances include an updated classification system, the description of alternative virus-like protein morphologies and capsid dynamics, and the further elucidation of the functions and roles of various viral proteins. Important milestones include new insights into cell tropism, host and microbial attachment factors and receptors, interactions with the cellular translational apparatus, and viral egress from cells. Noroviruses have been detected in previously unrecognised hosts and detection itself is facilitated by improved analytical techniques. New potential transmission routes and/or viral reservoirs have been proposed. Recent in vivo and in vitro findings have added to the understanding of host immunity in response to norovirus infection, and vaccine development has progressed to preclinical and even clinical trial testing. Ongoing development of therapeutics includes promising direct-acting small molecules and host-factor drugs.


Asunto(s)
Infecciones por Caliciviridae/diagnóstico , Infecciones por Caliciviridae/inmunología , Gastroenteritis/virología , Norovirus/genética , Norovirus/fisiología , Animales , Infecciones por Caliciviridae/epidemiología , Infecciones por Caliciviridae/transmisión , Proteínas de la Cápside/genética , Evolución Molecular , Interacciones Microbiota-Huesped , Humanos , Ratones , Norovirus/clasificación , Norovirus/inmunología , Desarrollo de Vacunas , Tropismo Viral , Replicación Viral
13.
Food Environ Virol ; 13(1): 93-106, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33389671

RESUMEN

Human noroviruses are a major cause for gastroenteritis outbreaks. Filter-feeding bivalve molluscs, which accumulate noroviruses in their digestive tissues, are a typical vector for human infection. RT-qPCR, the established method for human norovirus detection in food, does not allow discrimination between infectious and non-infectious viruses and can overestimate potentially infectious viral loads. To develop a more accurate method of infectious norovirus load estimation, we combined intercalating agent propidium monoazide (PMAxx™)-pre-treatment with RT-qPCR assay using in vitro-cultivable murine norovirus. Three primer sets targeting different genome regions and diverse amplicon sizes were used to compare one-step amplification of a short genome fragment to three two-step long-range RT-qPCRs (7 kbp, 3.6 kbp and 2.3 kbp amplicons). Following initial assays performed on untreated infectious, heat-, or ultraviolet-inactivated murine noroviruses in PBS suspension, PMAxx™ RT-qPCRs were implemented to detect murine noroviruses subsequent to their extraction from mussel digestive tissues; virus extraction via anionic polymer-coated magnetic beads was compared with the proteinase K-dependent ISO norm. The long-range RT-qPCR process detecting fragments of more than 2.3 kbp allowed accurate estimation of the infectivity of UV-damaged murine noroviruses. While proteinase K extraction limited later estimation of PMAxx™ pre-treatment effects and was found to be unsuited to the assay, magnetic bead-captured murine noroviruses retained their infectivity. Genome copies of heat-inactivated murine noroviruses differed by 2.3 log10 between RT-qPCR and PMAxx™-RT-qPCR analysis in bivalve molluscs, the PMAxx™ pre-treatment allowing a closer approximation of infectious titres. The combination of bead-based virus extraction and PMAxx™ RT-qPCR thus provides a more accurate model for the estimation of noroviral bivalve mollusc contamination than the conjunction of proteinase K extraction and RT-qPCR and has the potential (once validated utilising infectious human norovirus) to provide an added measure of security to food safety authorities in the hazard assessment of potential bivalve mollusc contamination.


Asunto(s)
Bivalvos/virología , Contaminación de Alimentos/análisis , Norovirus/aislamiento & purificación , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Mariscos/virología , Animales , Infecciones por Caliciviridae/virología , Gastroenteritis/virología , Humanos , Ratones , Norovirus/genética , ARN Viral/genética , ARN Viral/aislamiento & purificación
14.
Viruses ; 13(5)2021 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-34063220

RESUMEN

Viral recombination is a key mechanism in the evolution and diversity of noroviruses. In vivo, synchronous single-cell coinfection by multiple viruses, the ultimate prerequisite to viral recombination, is likely to be a rare event and delayed secondary infections are a more probable occurrence. Here, we determine the effect of a temporal separation of in vitro infections with the two homologous murine norovirus strains MNV-1 WU20 and CW1 on the composition of nascent viral populations. WU20 and CW1 were either synchronously inoculated onto murine macrophage cell monolayers (coinfection) or asynchronously applied (superinfection with varying titres of CW1 at half-hour to 24-h delays). Then, 24 h after initial co-or superinfection, quantification of genomic copy numbers and discriminative screening of plaque picked infectious progeny viruses demonstrated a time-dependent predominance of primary infecting WU20 in the majority of viral progenies. Our results indicate that a time interval from one to two hours onwards between two consecutive norovirus infections allows for the establishment of a barrier that reduces or prevents superinfection.


Asunto(s)
Infecciones por Caliciviridae/virología , Norovirus/fisiología , Enfermedades de los Roedores/virología , Interferencia Viral , Animales , Genoma Viral , Ratones , Células RAW 264.7 , ARN Viral , Recombinación Genética , Sobreinfección
15.
Food Environ Virol ; 13(4): 493-506, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34363588

RESUMEN

Human noroviruses impose a considerable health burden globally. Here, a flow cytometry approach designed for their detection in biological waste and food samples was developed using antibody-coated magnetic beads. Antipeptide antibodies against murine norovirus and various human norovirus genotypes were generated for capture and coated onto magnetic beads. A flow cytometry assay was then implemented to detect bead-bound human norovirus GI.3 in patient stool samples and in norovirus-spiked mussel digestive tissues. The detection limit for stool samples was 105 gc/mL, thus bettering detection limits of commercially available norovirus diagnosis quick kits of 100-fold; the detection limit in spiked mussels however was ten-fold higher than in stool samples. Further assays showed a decrease in fluorescence intensity for heat- or UV-inactivated virus particles. Overall, we demonstrate the application of a flow cytometry approach for direct detection of small non-enveloped virus particles such as noroviruses. An adaptation of the technology to routine diagnostics has the potential to contribute a rapid and sensitive tool to norovirus outbreak investigations. Further improvements to the method, notably decreasing the detection limit of the approach, may allow the analysis of naturally contaminated food and environmental samples.


Asunto(s)
Bivalvos , Norovirus , Animales , Citometría de Flujo , Humanos , Inmunoensayo , Fenómenos Magnéticos , Ratones , Norovirus/genética
16.
Transbound Emerg Dis ; 68(5): 2761-2773, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33713549

RESUMEN

Since the introduction in Georgia in 2007 of an African swine fever (ASF) genotype 2 virus strain, the virus has rapidly spread to both Western European and Asian countries. It now constitutes a major threat for the global swine industry. The ongoing European transmission cycle has been related to the 'wild boar habitat' with closed transmission events between wild boar populations and incidental spillovers to commercial and non-commercial (backyard) pig holdings. During the epidemic in Belgium, only wild boar were infected and although the introduction route has not yet been elucidated, the 'human factor' is highly suspected. While ASF was successfully contained in a small region in the Southern part of Belgium without affecting domestic pigs, the risk of spillover at the wild/domestic interface remains poorly assessed. In this study, we used a semi-quantitative method, involving national and international experts, to assess the risk associated with different transmission routes for ASF introduction from wild boar to domestic pig holdings and subsequent dissemination between holdings in the Belgian epidemiological context. Qualitative responses obtained by our questionnaire were numerically transformed and statistically processed to provide a semi-quantitative assessment of the occurrence of the hazard and a ranking of all transmission routes. 'Farmer', 'bedding material', 'veterinarian' and 'professionals from the pig sector' were considered as the most important transmission routes for ASF introduction from the wild reservoir to pig holdings. 'Animal movements', 'farmer', 'veterinarian', 'iatrogenic', 'animal transport truck' and 'animal care equipment' were considered as the most important transmission routes posing a risk of ASF spread between pig holdings. Combined with specific biosecurity checks in the holdings, this assessment helps in prioritizing risk mitigation measures against ASF introduction and further spread in the domestic pig industry, particularly while the ASF situation in Western Europe is worsening.


Asunto(s)
Virus de la Fiebre Porcina Africana , Fiebre Porcina Africana , Enfermedades de los Porcinos , Fiebre Porcina Africana/epidemiología , Animales , Bélgica/epidemiología , Brotes de Enfermedades/veterinaria , Medición de Riesgo , Sus scrofa , Porcinos
17.
J Gen Virol ; 91(Pt 11): 2723-33, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20702654

RESUMEN

Based on sequencing data, norovirus (NoV) recombinants have been described, but no experimental evidence of recombination in NoVs has been documented. Using the murine norovirus (MNV) model, we investigated the occurrence of genetic recombination between two co-infecting wild-type MNV isolates in RAW cells. The design of a PCR-based genotyping tool allowed accurate discrimination between the parental genomes and the detection of a viable recombinant MNV (Rec MNV) in the progeny viruses. Genetic analysis of Rec MNV identified a homologous-recombination event located at the ORF1-ORF2 overlap. Rec MNV exhibited distinct growth curves and produced smaller plaques than the wild-type MNV in RAW cells. Here, we demonstrate experimentally that MNV undergoes homologous recombination at the previously described recombination hot spot for NoVs, suggesting that the MNV model might be suitable for in vitro studies of NoV recombination. Moreover, the results show that exchange of genetic material between NoVs can generate viruses with distinct biological properties from the parental viruses.


Asunto(s)
Norovirus/crecimiento & desarrollo , Norovirus/genética , ARN Viral/genética , Recombinación Genética , Animales , Línea Celular , Análisis por Conglomerados , Genotipo , Macrófagos/virología , Ratones , Viabilidad Microbiana , Datos de Secuencia Molecular , Norovirus/patogenicidad , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Análisis de Secuencia de ADN , Homología de Secuencia , Ensayo de Placa Viral , Virulencia
18.
Arch Virol ; 154(11): 1841-5, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19816652

RESUMEN

Two genotypes (Jena and Newbury2) and two intergenotype recombinant strains have been recognized in bovine noroviruses. Several studies have shown an apparent predominance of bovine infection with Newbury2-related (genotype 2) strains. Bovine stool samples were screened with two primer pairs targeting both the polymerase and the capsid genes. Among the predominant genotype 2 sequences, two were genetically related to the recombinant strain Thirsk10. The detection of sequences genetically related to Thirsk10, together with the very low rate of detection of Jena-related sequences, characterized the bovine norovirus population in Belgium, a representative region of continental Europe. Unexpectedly, bovine kobuvirus-related sequences were also amplified, extending their distribution area in Europe.


Asunto(s)
Infecciones por Caliciviridae/veterinaria , Enfermedades de los Bovinos/virología , Kobuvirus/genética , Norovirus/genética , Infecciones por Picornaviridae/veterinaria , Virus Reordenados/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Infecciones por Caliciviridae/epidemiología , Infecciones por Caliciviridae/virología , Bovinos , Enfermedades de los Bovinos/epidemiología , Europa (Continente)/epidemiología , Genoma Viral , Genotipo , Datos de Secuencia Molecular , Filogenia , Infecciones por Picornaviridae/epidemiología , Infecciones por Picornaviridae/virología , Proteínas Virales/química
19.
Virol J ; 5: 94, 2008 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-18702817

RESUMEN

BACKGROUND: Noroviruses are single-stranded RNA viruses belonging to the family Caliciviridae. They are a major cause of epidemic and sporadic gastroenteritis in humans and clinical signs and lesions of gastroenteritis were reported in bovines. Due to their genetic proximity, potential zoonotic transmission or animal reservoir can be hypothesized for noroviruses. RT-PCR has become the "gold standard" for the detection of noroviruses in faecal and environmental samples. With such samples, the control for inhibition of the reaction during amplification and detection is crucial to avoid false negative results, which might otherwise not be detected. The aim of the reported method is to detect, with a SYBR Green technology, a broad range of noroviruses with a control for inhibition. RESULTS: A SYBR Green real-time RT-PCR assay was developed making use of a foreign internal RNA control added in the same tube. This assay is able to detect human and bovine noroviruses belonging to genogroups I, II and III and to distinguish between norovirus and internal control amplicons using melting curve analysis. A 10-fold dilution of samples appears to be the method of choice to remove inhibition. This assay was validated with human and bovine stool samples previously tested for norovirus by conventional RT-PCR. CONCLUSION: This SYBR Green real-time RT-PCR assay allows the detection of the most important human and bovine noroviruses in the same assay, and avoids false negative results making use of an internal control. Melting curves allow the discrimination between the internal control and norovirus amplicons. It gives preliminary information about the species of origin. The sensitivity of the developed assay is higher than conventional RT-PCR and a 10-fold dilution of samples showed a better efficiency and reproducibility to remove RT-PCR inhibition than addition of bovine serum albumin.


Asunto(s)
Infecciones por Caliciviridae/diagnóstico , Heces/virología , Gastroenteritis/diagnóstico , Norovirus/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Animales , Infecciones por Caliciviridae/virología , Bovinos , Colorantes Fluorescentes , Gastroenteritis/virología , Humanos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
20.
Arch Virol ; 153(10): 1927-31, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18777158

RESUMEN

Porcine noroviruses and sapoviruses belong to the family Caliciviridae and are rarely reported in European countries. In this study, swine stools from a region representative of northern Europe were screened for these viruses by RT-PCR. Both porcine noroviruses and sapoviruses were detected, showing their circulation in this region. The porcine norovirus strains were genetically related to genotype 19 strains in the genogroup II of the genus Norovirus. The porcine sapovirus strains were genetically related to the porcine enteric calicivirus Cowden reference strain and to newly described porcine strains in the genus Sapovirus.


Asunto(s)
Infecciones por Caliciviridae/veterinaria , Norovirus/clasificación , Norovirus/aislamiento & purificación , Sapovirus/clasificación , Sapovirus/aislamiento & purificación , Enfermedades de los Porcinos/virología , Animales , Bélgica , Infecciones por Caliciviridae/virología , Heces/virología , Genotipo , Datos de Secuencia Molecular , Filogenia , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADN , Porcinos
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