Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Emerg Infect Dis ; 30(8): 1631-1641, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39043393

RESUMO

A globally implemented unified phylogenetic classification for human respiratory syncytial virus (HRSV) below the subgroup level remains elusive. We formulated global consensus of HRSV classification on the basis of the challenges and limitations of our previous proposals and the future of genomic surveillance. From a high-quality curated dataset of 1,480 HRSV-A and 1,385 HRSV-B genomes submitted to GenBank and GISAID (https://www.gisaid.org) public sequence databases through March 2023, we categorized HRSV-A/B sequences into lineages based on phylogenetic clades and amino acid markers. We defined 24 lineages within HRSV-A and 16 within HRSV-B and provided guidelines for defining prospective lineages. Our classification demonstrated robustness in its applicability to both complete and partial genomes. We envision that this unified HRSV classification proposal will strengthen HRSV molecular epidemiology on a global scale.


Assuntos
Genoma Viral , Filogenia , Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano , Vírus Sincicial Respiratório Humano/genética , Vírus Sincicial Respiratório Humano/classificação , Humanos , Infecções por Vírus Respiratório Sincicial/virologia , Infecções por Vírus Respiratório Sincicial/epidemiologia
2.
Emerg Infect Dis ; 27(6): 1-9, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34013862

RESUMO

Human respiratory syncytial virus (HRSV) is the leading viral cause of serious pediatric respiratory disease, and lifelong reinfections are common. Its 2 major subgroups, A and B, exhibit some antigenic variability, enabling HRSV to circulate annually. Globally, research has increased the number of HRSV genomic sequences available. To ensure accurate molecular epidemiology analyses, we propose a uniform nomenclature for HRSV-positive samples and isolates, and HRSV sequences, namely: HRSV/subgroup identifier/geographic identifier/unique sequence identifier/year of sampling. We also propose a template for submitting associated metadata. Universal nomenclature would help researchers retrieve and analyze sequence data to better understand the evolution of this virus.


Assuntos
Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano , Criança , Variação Genética , Genótipo , Humanos , Epidemiologia Molecular , Filogenia , Vírus Sincicial Respiratório Humano/genética
3.
Virus Evol ; 6(2): veaa052, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33072402

RESUMO

Since the first human respiratory syncytial virus (HRSV) genotype classification in 1998, inconsistent conclusions have been drawn regarding the criteria that define HRSV genotypes and their nomenclature, challenging data comparisons between research groups. In this study, we aim to unify the field of HRSV genotype classification by reviewing the different methods that have been used in the past to define HRSV genotypes and by proposing a new classification procedure, based on well-established phylogenetic methods. All available complete HRSV genomes (>12,000 bp) were downloaded from GenBank and divided into the two subgroups: HRSV-A and HRSV-B. From whole-genome alignments, the regions that correspond to the open reading frame of the glycoprotein G and the second hypervariable region (HVR2) of the ectodomain were extracted. In the resulting partial alignments, the phylogenetic signal within each fragment was assessed. Maximum likelihood phylogenetic trees were reconstructed using the complete genome alignments. Patristic distances were calculated between all pairs of tips in the phylogenetic tree and summarized as a density plot in order to determine a cutoff value at the lowest point following the major distance peak. Our data show that neither the HVR2 fragment nor the G gene contains sufficient phylogenetic signal to perform reliable phylogenetic reconstruction. Therefore, whole-genome alignments were used to determine HRSV genotypes. We define a genotype using the following criteria: a bootstrap support of ≥ 70 per cent for the respective clade and a maximum patristic distance between all members of the clade of ≤0.018 substitutions per site for HRSV-A or ≤0.026 substitutions per site for HRSV-B. By applying this definition, we distinguish twenty-three genotypes within subtype HRSV-A and six genotypes within subtype HRSV-B. Applying the genotype criteria on subsampled data sets confirmed the robustness of the method.

4.
J Clin Virol ; 94: 72-78, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28772168

RESUMO

BACKGROUND: Acute Respiratory Infections (ARIs) are a major health problem, especially in young children and the elderly. OBJECTIVES: Insights into the seasonality of respiratory viruses can help us understand when the burden on society is highest and which age groups are most vulnerable. STUDY DESIGN: We monitored six respiratory viruses during five consecutive seasons (2011-2016) in Belgium. Patient specimens (n=22876), tested for one or more of the following respiratory viruses, were included in this analysis: Influenza viruses (IAV & IBV), Human respiratory syncytial virus (hRSV), Human metapneumovirus (hMPV), Adenovirus (ADV) and Human parainfluenza virus (hPIV). Data were analysed for four age categories: <6y, 6-17y, 18-64y and ≥65y. RESULTS: Children <6y had the highest infection rates (39% positive vs. 20% positive adults) and the highest frequency of co-infections. hRSV (28%) and IAV (32%) caused the most common respiratory viral infections and followed, like hMPV, a seasonal pattern with winter peaks. hRSV followed an annual pattern with two peaks: first in young children and ±7 weeks later in elderly. This phenomenon has not been described in literature so far. hPIV and ADV occurred throughout the year with higher rates in winter. CONCLUSIONS: Children <6y are most vulnerable for respiratory viral infections and have a higher risk for co-infections. hRSV and IAV are the most common respiratory infections with peaks during the winter season in Belgium.


Assuntos
Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bélgica/epidemiologia , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Estações do Ano , Adulto Jovem
5.
Dis Model Mech ; 9(10): 1203-1210, 2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27483350

RESUMO

Hepatitis E virus (HEV) is one of the prime causes of acute viral hepatitis, and chronic hepatitis E is increasingly recognized as an important problem in the transplant setting. Nevertheless, the fundamental understanding of the biology of HEV replication is limited and there are few therapeutic options. The development of such therapies is partially hindered by the lack of a robust and convenient animal model. We propose the infection of athymic nude rats with the rat HEV strain LA-B350 as such a model. A cDNA clone, pLA-B350, was constructed and the infectivity of its capped RNA transcripts was confirmed in vitro and in vivo Furthermore, a subgenomic replicon, pLA-B350/luc, was constructed and validated for in vitro antiviral studies. Interestingly, rat HEV proved to be less sensitive to the antiviral activity of α-interferon, ribavirin and mycophenolic acid than genotype 3 HEV (a strain that infects humans). As a proof-of-concept, part of the C-terminal polymerase sequence of pLA-B350/luc was swapped with its genotype 3 HEV counterpart: the resulting chimeric replicon replicated with comparable efficiency as the wild-type construct, confirming that LA-B350 strain is amenable to humanization (replacement of certain sequences or motifs by their counterparts from human HEV strains). Finally, ribavirin effectively inhibited LA-B350 replication in athymic nude rats, confirming the suitability of the rat model for antiviral studies.


Assuntos
Vírus da Hepatite E/fisiologia , Hepatite E/virologia , Animais , Antivirais/farmacologia , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/virologia , Linhagem Celular Tumoral , Células Clonais , DNA Complementar/genética , Modelos Animais de Doenças , Suscetibilidade a Doenças , Hepatite E/patologia , Vírus da Hepatite E/efeitos dos fármacos , Humanos , Fígado/patologia , Fígado/virologia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/virologia , Camundongos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Viral/administração & dosagem , RNA Polimerase Dependente de RNA/metabolismo , Ratos Nus , Replicon/genética , Replicação Viral/efeitos dos fármacos , Eliminação de Partículas Virais/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA