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1.
J Gen Virol ; 105(5)2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38695722

RESUMO

High-pathogenicity avian influenza viruses (HPAIVs) of the goose/Guangdong lineage are enzootically circulating in wild bird populations worldwide. This increases the risk of entry into poultry production and spill-over to mammalian species, including humans. Better understanding of the ecological and epizootiological networks of these viruses is essential to optimize mitigation measures. Based on full genome sequences of 26 HPAIV samples from Iceland, which were collected between spring and autumn 2022, as well as 1 sample from the 2023 summer period, we show that 3 different genotypes of HPAIV H5N1 clade 2.3.4.4b were circulating within the wild bird population in Iceland in 2022. Furthermore, in 2023 we observed a novel introduction of HPAIV H5N5 of the same clade to Iceland. The data support the role of Iceland as an utmost northwestern distribution area in Europe that might act also as a potential bridging point for intercontinental spread of HPAIV across the North Atlantic.


Assuntos
Virus da Influenza A Subtipo H5N1 , Influenza Aviária , Filogenia , Islândia/epidemiologia , Animais , Influenza Aviária/virologia , Influenza Aviária/epidemiologia , Influenza Aviária/transmissão , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Genótipo , Animais Selvagens/virologia , Vírus da Influenza A/genética , Vírus da Influenza A/classificação , Vírus da Influenza A/isolamento & purificação , Genoma Viral , Aves/virologia
2.
Emerg Infect Dis ; 28(12): 2383-2388, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36261139

RESUMO

Highly pathogenic avian influenza viruses (HPAIVs) of hemagglutinin type H5 and clade 2.3.4.4b have widely spread within the northern hemisphere since 2020 and threaten wild bird populations, as well as poultry production. We present phylogeographic evidence that Iceland has been used as a stepping stone for HPAIV translocation from northern Europe to North America by infected but mobile wild birds. At least 2 independent incursions of HPAIV H5N1 clade 2.3.4.4b assigned to 2 hemagglutinin clusters, B1 and B2, are documented for summer‒autumn 2021 and spring 2022. Spread of HPAIV H5N1 to and among colony-breeding pelagic avian species in Iceland is ongoing. Potentially devastating effects (i.e., local losses >25%) on these species caused by extended HPAIV circulation in space and time are being observed at several affected breeding sites throughout the North Atlantic.


Assuntos
Virus da Influenza A Subtipo H5N1 , Vírus da Influenza A , Influenza Aviária , Animais , Influenza Aviária/epidemiologia , Islândia/epidemiologia , Hemaglutininas , Vírus da Influenza A/genética , Animais Selvagens , Aves , Europa (Continente)/epidemiologia , América do Norte/epidemiologia , Filogenia
3.
J Virol ; 79(24): 15038-42, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16306574

RESUMO

Maedi-visna virus (MVV) is a lentivirus of sheep sharing several key features with the primate lentiviruses. The virus causes slowly progressive diseases, mainly in the lungs and the central nervous system of sheep. Here, we investigate the molecular basis for the differential growth phenotypes of two MVV isolates. One of the isolates, KV1772, replicates well in a number of cell lines and is highly pathogenic in sheep. The second isolate, KS1, no longer grows on macrophages or causes disease. The two virus isolates differ by 129 nucleotide substitutions and two deletions of 3 and 15 nucleotides in the env gene. To determine the molecular nature of the lesions responsible for the restrictive growth phenotype, chimeric viruses were constructed and used to map the phenotype. An L120R mutation in the CA domain, together with a P205S mutation in Vif (but neither alone), could fully convert KV1772 to the restrictive growth phenotype. These results suggest a functional interaction between CA and Vif in MVV replication, a property that may relate to the innate antiretroviral defense mechanisms in sheep.


Assuntos
Produtos do Gene vif/fisiologia , Macrófagos/virologia , Vírus Visna-Maedi/fisiologia , Animais , DNA Viral/análise , Produtos do Gene vif/genética , Genoma Viral , Mutação , Ovinos , Doenças dos Ovinos/virologia , Replicação Viral , Vírus Visna-Maedi/patogenicidade
4.
Vaccine ; 23(24): 3223-8, 2005 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-15837223

RESUMO

Four sheep were infected intratracheally with an attenuated molecular clone of maedi-visna virus (MVV). All four became infected. Ten months later these sheep were challenged intratracheally with a genetically similar but pathogenic clone of MVV. Four unvaccinated sheep were infected simultaneously. All sheep became infected by the challenge virus. The vaccinated sheep were not protected against superinfection with the challenge clone. However, virus was isolated more frequently from the blood of the unvaccinated controls than of the vaccinated animals and ten times more frequently from lungs of unvaccinated sheep than from lungs of vaccinated sheep at sacrifice, indicating partial protection.


Assuntos
Imunidade nas Mucosas/imunologia , Vacinas Virais/imunologia , Vírus Visna-Maedi/imunologia , Visna/imunologia , Animais , Anticorpos Antivirais/análise , Anticorpos Antivirais/biossíntese , Clonagem Molecular , Ensaio de Imunoadsorção Enzimática , Feminino , Hibridização In Situ , Ovinos , Superinfecção/prevenção & controle , Vacinas Atenuadas/imunologia , Carga Viral , Visna/prevenção & controle , Visna/virologia , Vírus Visna-Maedi/isolamento & purificação
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