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1.
Viruses ; 13(11)2021 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-34835129

RESUMO

Once low-pathogenic avian influenza viruses (LPAIVs) of the H5 and H7 subtypes from wild birds enter into poultry species, there is the possibility of them mutating into highly pathogenic avian influenza viruses (HPAIVs), resulting in severe epizootics with up to 100% mortality. This mutation from a LPAIV to HPAIV strain is the main cause of an AIV's major economic impact on poultry production. Although AIVs are inextricably linked to their hosts in their evolutionary history, the contribution of host-related factors in the emergence of HPAI viruses has only been marginally explored so far. In this study, transcriptomic sequencing of tracheal tissue from chickens infected with four distinct LP H7 viruses, characterized by a different history of pathogenicity evolution in the field, was implemented. Despite the inoculation of a normalized infectious dose of viruses belonging to the same subtype (H7) and pathotype (LPAI), the use of animals of the same age, sex and species as well as the identification of a comparable viral load in the target samples, the analyses revealed a heterogeneity in the gene expression profile in response to infection with each of the H7 viruses administered.

2.
Viruses ; 13(8)2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34452311

RESUMO

Since 2006, multiple outbreaks of avian influenza (AI) have been reported in Nigeria involving different subtypes. Surveillance and molecular epidemiology have revealed the vital role of live bird markets (LBMs) in the dissemination of AI virus to commercial poultry farms. To better understand the ecology and epidemiology of AI in Nigeria, we performed whole-genome sequencing of nineteen H9N2 viruses recovered, from apparently healthy poultry species, during active surveillance conducted in nine LBMs across Nigeria in 2019. Analyses of the HA gene segment of these viruses showed that the H9N2 strains belong to the G1 lineage, which has zoonotic potential, and are clustered with contemporary H9N2 identified in Africa between 2016 and 2020. We observed two distinct clusters of H9N2 viruses in Nigeria, suggesting different introductions into the country. In view of the zoonotic potential of H9N2 and the co-circulation of multiple subtypes of AI virus in Nigeria, continuous monitoring of the LBMs across the country and molecular characterization of AIVs identified is advocated to mitigate economic losses and public health threats.

3.
Transbound Emerg Dis ; 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33480188

RESUMO

Among recurrent sanitary emergencies able to spread rapidly worldwide, avian influenza is one of the main constraints for animal health and food security. In West Africa, Nigeria has been experiencing repeated outbreaks of different strains of avian influenza virus (AIV) since 2006 and is also recognized as a hot spot in the region for the introduction of emerging strains by migratory wild birds. Here, we generated complete genomes of 20 highly pathogenic avian influenza (HPAI) H5N8 viruses collected during active surveillance in Nigerian live bird markets (LBM) and from outbreaks reported in the country between 2016 and 2019. Phylogenetic analysis reveals that the Nigerian viruses cluster into four separate genetic groups within HPAI H5 clade 2.3.4.4b. The first group includes 2016-2017 Nigerian viruses with high genetic similarity to H5N8 viruses detected in Central African countries, while the second includes Nigerian viruses collected both in LBM and poultry farms (2018-2019), as well as in Cameroon, Egypt and Siberia. A natural reassortant strain identified in 2019 represents the third group: H5N8 viruses with the same gene constellation were identified in 2018 in South Africa. Finally, the fourth introduction represents the first detection in the African continent of the H5N6 subtype, which is related to European viruses. Bayesian phylogeographic analyses confirmed that the four introductions originated from different sources and provide evidence of the virus spread within Nigeria, as well as diffusion beyond its borders. The multiple epidemiological links between Nigeria, Central and Southern African countries highlight the need for harmonized and coordinated surveillance system to control AIV impact. Improved surveillance at the Wetlands, LBMs and early warning of outbreaks are crucial for prevention and control of AIV, which can be potentially zoonotic and be a threat to human health.

4.
Infect Genet Evol ; 84: 104359, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32407794

RESUMO

Canine distemper virus (CDV) represents an important threat for both wild and domestic carnivores. Since 2006, the North-Eastern regions in Italy have been experiencing severe and widespread recurring outbreaks of CDV affecting the wild carnivore population. In this study we performed an extensive phylogeographic analysis of CDV strains belonging to the Wildlife-Europe genetic group identified between 2006 and 2018 in Veneto, Trentino Alto Adige and Friuli Venezia Giulia regions. Our analysis revealed that viruses from the first (2006-2009) and the second (2011-2018) epidemic wave cluster separately, suggesting the introduction of two distinct genetic variants. These two events were characterized by different diffusion rates and spatial distribution, thus suggesting the existence of a connection between infection spread and host population dynamics. We also report the first spillover event of this strain to a non-vaccinated dog in a rural area of Friuli Venezia Giulia. The increasing prevalence of the infection in wildlife population, the broad host range of CDV circulating in the Alpine wildlife and the first reported transmission of a wild-adapted strain to a domestic dog in this region raise concerns over the vulnerability of wildlife species and the exposure of our pets to new threatening strains. Understanding the dynamic of CDV epidemics will also improve preparedness for re-emerging diseases affecting carnivore species.


Assuntos
Animais Selvagens/virologia , Vírus da Cinomose Canina/genética , Cinomose/epidemiologia , Animais , Vírus da Cinomose Canina/isolamento & purificação , Raposas/virologia , Itália/epidemiologia , Filogenia , Filogeografia , Análise Espaço-Temporal
5.
Emerg Microbes Infect ; 9(1): 886-888, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32312185

RESUMO

Since 2013, highly pathogenic avian influenza (HPAI) subtype H5N6 (clade 2.3.4.4) has been reported in wild birds and poultry in Asia as well as in other parts of the globe. In Africa, information on the presence of this virus subtype is lacking. This study reports the first detection of a HPAI (H5N6) virus (clade 2.3.4.4b) in a duck from a live bird market in Nigeria, whose genome is closely related to the European 2017-2018 H5N6 viruses, indricating a recent virus introduction into the African continent.


Assuntos
Animais Selvagens/virologia , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/epidemiologia , Filogenia , Doenças das Aves Domésticas/virologia , Aves Domésticas/virologia , Animais , Surtos de Doenças/veterinária , Patos/virologia , Genoma Viral , Vírus da Influenza A/classificação , Influenza Aviária/virologia , Nigéria/epidemiologia , Doenças das Aves Domésticas/epidemiologia
6.
Avian Pathol ; 48(5): 470-476, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31142135

RESUMO

Between November 2017 and February 2018, Ghanaian poultry producers reported to animal health authorities a dramatic increase in mortality rate and a relevant drop in egg production in several layer hen farms. Laboratory investigations revealed that the farms had been infected by the H9N2 influenza subtype. Virological and molecular characterization of the viruses identified in Ghana is described here for the first time. Whole genome analysis showed that the viruses belong to the G1-lineage and cluster with viruses identified in North and West Africa. The low pathogenicity of the virus was confirmed by the intravenous pathogenicity index assay. Further investigations revealed co-infection with infectious bronchitis virus of the GI-19 lineage, which very likely explained the severity of the disease observed during the outbreaks. The H9N2 outbreaks in Ghana highlight the importance of performing a differential diagnosis and an in-depth characterization of emerging viruses. In addition, the detection of a potentially zoonotic subtype, such as the H9N2, in a region where highly pathogenic avian influenza H5Nx is currently circulating highlights the urgency of implementing enhanced monitoring strategies and supporting improved investments in regional diagnostic technologies. RESEARCH HIGHLIGHTS Influenza A H9N2 subtype was detected in layer hens in Ghana in 2017-2018 Whole genome characterization of seven H9N2 viruses was performed Phylogenetic trees revealed that the H9N2 viruses belong to the G1 lineage The HA protein possesses the amino acid mutations 226L and 155T Co-infection with infectious bronchitis virus of the GI-19 lineage was identified.


Assuntos
Infecções por Coronavirus/veterinária , Surtos de Doenças/veterinária , Genoma Viral/genética , Vírus da Bronquite Infecciosa/isolamento & purificação , Vírus da Influenza A Subtipo H9N2/isolamento & purificação , Influenza Aviária/epidemiologia , Animais , Galinhas , Coinfecção/veterinária , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Gana/epidemiologia , Vírus da Bronquite Infecciosa/genética , Vírus da Bronquite Infecciosa/patogenicidade , Vírus da Influenza A Subtipo H9N2/genética , Vírus da Influenza A Subtipo H9N2/patogenicidade , Influenza Aviária/virologia , Filogenia
8.
Poult Sci ; 97(10): 3501-3509, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29897603

RESUMO

Infectious bronchitis (IB) control has a strong impact on poultry farming, because of the necessary epidemiological knowledge for planning the best strategy, the optimal strain association, the priming and boosting interventions. Broiler farming is even more problematic given the short and intense productive cycle, which requires an early onset of protection against most of the infectious threats, possibly with limited respiratory post-vaccination reactions that would have a direct impact on the bird health and productivity. For this purpose, gel vaccination has been proposed as a new approach for infectious bronchitis virus (IBV) control and vaccine intake, kinetics and compatibility of combined strains administered by gel have been analyzed in this study. After gel vaccination with single and combined 1/96 and B-48 strains on 4 groups of commercial broilers, a 21-d-long experimental trial has been conducted to monitor the vaccine safety by clinical assessment and vaccine kinetics by strain-specific real-time RT-PCR on choanal cleft swabs. The vaccine strains administered by gel were safe and negligible respiratory signs were detected, even when combined. Vaccine titers were compared among groups and within the same group among a 10-bird pooled sample and 10 swabs from individually sampled birds. 1/96 strain early reached high titers in all animals, while B-48 presence was less constant even though it was detected in almost all birds before the trial end. The individual and pooled sample comparison revealed a partial overestimation of vaccine titers in the pooled samples and the loss of the prevalence data, although the trend portrayed by the pooled swabs closely followed the individual ones.


Assuntos
Galinhas , Infecções por Coronavirus/veterinária , Vírus da Bronquite Infecciosa/imunologia , Doenças das Aves Domésticas/prevenção & controle , Vacinação/veterinária , Vacinas Virais/uso terapêutico , Animais , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Cinética , Doenças das Aves Domésticas/virologia , Vacinas Combinadas/uso terapêutico
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