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1.
Elife ; 102021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34414887

RESUMO

Identifying the key vector and host species that drive the transmission of zoonotic pathogens is notoriously difficult but critical for disease control. We present a nested approach for quantifying the importance of host and vectors that integrates species' physiological competence with their ecological traits. We apply this framework to a medically important arbovirus, Ross River virus (RRV), in Brisbane, Australia. We find that vertebrate hosts with high physiological competence are not the most important for community transmission; interactions between hosts and vectors largely underpin the importance of host species. For vectors, physiological competence is highly important. Our results identify primary and secondary vectors of RRV and suggest two potential transmission cycles in Brisbane: an enzootic cycle involving birds and an urban cycle involving humans. The framework accounts for uncertainty from each fitted statistical model in estimates of species' contributions to transmission and has has direct application to other zoonotic pathogens.


Assuntos
Infecções por Alphavirus/virologia , Aves/virologia , Culicidae/virologia , Reservatórios de Doenças/virologia , Vetores de Doenças , Vírus do Rio Ross/patogenicidade , Zoonoses Virais , Infecções por Alphavirus/transmissão , Animais , Interações Hospedeiro-Patógeno , Humanos , Modelos Biológicos , Queensland , Virulência
2.
Sci Rep ; 11(1): 16293, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34381119

RESUMO

That the high frequency and good replication capacity of strains with reduced susceptibility to neuraminidase inhibitors (NAIs) in highly pathogenic avian influenza H7N9 (HPAI H7N9) virus made it a significance to further study its drug resistance. HPAI H7N9 viruses bearing NA I222L or E119V substitution and two mutations of I222L-E119V as well as their NAIs-sensitive counterpart were generated by reverse genetics for NA inhibition test and replication capability evaluation in vitro. The attenuated H7N9/PR8 recombinant viruses were developed to study the pathogenicity and drug resistance brought by the above substitutions to mice. The IC50 fold change of oseltamivir to HPAI H7N9 with NA222L-119V is 306.34 times than that of its susceptible strain, and 3.5 times than the E119V mutant virus. HPAI H7N9 bearing NA222L-119V had good replication ability with peak value of more than 6log10 TCID50/ml in MDCK cells. H7N9/PR8 virus bearing NA222L-119V substitutions leaded to diffuse pneumonia, significant weight loss and fatality in mice. NA E119V made H7N9/PR8 virus resistant to oseltamivir, and I222L-E119V had synergistic resistance to oseltamivir in mice. Due to the good fitness of drug resistant strains of HPAI H7N9 virus, it is necessary to strengthen drug resistance surveillance and new drug research.


Assuntos
Substituição de Aminoácidos/genética , Farmacorresistência Viral/genética , Subtipo H7N9 do Vírus da Influenza A/efeitos dos fármacos , Subtipo H7N9 do Vírus da Influenza A/genética , Neuraminidase/genética , Oseltamivir/farmacologia , Substituição de Aminoácidos/efeitos dos fármacos , Animais , Antivirais/farmacologia , Aves/virologia , Linhagem Celular , Cães , Inibidores Enzimáticos/farmacologia , Feminino , Células HEK293 , Humanos , Influenza Aviária/tratamento farmacológico , Influenza Aviária/virologia , Influenza Humana/tratamento farmacológico , Influenza Humana/virologia , Células Madin Darby de Rim Canino , Camundongos , Camundongos Endogâmicos C57BL , Mutação/genética , Infecções por Orthomyxoviridae/tratamento farmacológico , Infecções por Orthomyxoviridae/virologia , Proteínas Virais/genética , Replicação Viral/efeitos dos fármacos , Replicação Viral/genética
3.
Viruses ; 13(7)2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34372564

RESUMO

Avian bornaviruses were first described in 2008 as the causative agents of proventricular dilatation disease (PDD) in parrots and their relatives (Psittaciformes). To date, 15 genetically highly diverse avian bornaviruses covering at least five viral species have been discovered in different bird orders. Currently, the primary diagnostic tool is the detection of viral RNA by conventional or real-time RT-PCR (rRT-PCR). One of the drawbacks of this is the usage of either specific assays, allowing the detection of one particular virus, or of assays with a broad detection spectrum, which, however, do not allow for the simultaneous specification of the detected virus. To facilitate the simultaneous detection and specification of avian bornaviruses, a multiplex real-time RT-PCR assay was developed. Whole-genome sequences of various bornaviruses were aligned. Primers were designed to recognize conserved regions within the overlapping X/P gene and probes were selected to detect virus species-specific regions within the target region. The optimization of the assay resulted in the sensitive and specific detection of bornaviruses of Psittaciformes, Passeriformes, and aquatic birds. Finally, the new rRT-PCR was successfully employed to detect avian bornaviruses in field samples from various avian species. This assay will serve as powerful tool in epidemiological studies and will improve avian bornavirus detection.


Assuntos
Bornaviridae/genética , Bornaviridae/isolamento & purificação , Reação em Cadeia da Polimerase Multiplex/métodos , Animais , Doenças das Aves/virologia , Aves/genética , Aves/virologia , Primers do DNA/genética , Genoma Viral , Infecções por Mononegavirales/veterinária , Papagaios/genética , Papagaios/virologia , Passeriformes/genética , Passeriformes/virologia , Filogenia , RNA Viral/genética , Sequenciamento Completo do Genoma/métodos
4.
Viruses ; 13(7)2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34372573

RESUMO

West Nile (WNV) and Usutu (USUV) viruses are mosquito-borne flaviviruses. Thanks to their importance as zoonotic diseases, a regional plan for surveillance of Arboviruses was implemented in Emilia-Romagna in 2009. The province of Ferrara belongs to the Emilia-Romagna region, and it is an endemic territory for these viruses, with favorable ecological conditions for abundance of mosquitoes and wild birds. From 2015 to 2019, we collected 1842 dead-found birds at a wildlife rehabilitation center, which were analysed by three different PCRs for the detection of WNV and USUV genomes. August was characterized by the highest infection rate for both viruses. Columbiformes scored the highest USUV prevalence (8%), while Galliformes and Strigiformes reported the highest prevalence for WNV (13%). Among Passeriformes (the most populated Order), Turdus merula was the most abundant species and scored the highest prevalence for both viruses. To optimize passive surveillance plans, monitoring should be focused on the summer and towards the avian species more prone to infection by both viruses.


Assuntos
Aves/virologia , Infecções por Flavivirus/epidemiologia , Febre do Nilo Ocidental/epidemiologia , Animais , Culicidae/virologia , Monitoramento Epidemiológico/veterinária , Flavivirus/genética , Flavivirus/patogenicidade , Infecções por Flavivirus/veterinária , Itália/epidemiologia , Doenças Transmitidas por Vetores/epidemiologia , Doenças Transmitidas por Vetores/veterinária , Febre do Nilo Ocidental/veterinária , Vírus do Nilo Ocidental/genética , Vírus do Nilo Ocidental/patogenicidade
5.
Virology ; 563: 20-27, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34411808

RESUMO

Viruses of the subfamily Orthocoronavirinae can cause mild to severe disease in people, including COVID-19, MERS and SARS. Their most common natural hosts are bat and bird species, which are mostly split across four virus genera. Molecular clock analyses of orthocoronaviruses suggested the most recent common ancestor of these viruses might have emerged either around 10,000 years ago or, using models accounting for selection, many millions of years. Here, we reassess the evolutionary history of these viruses. We present time-aware phylogenetic analyses of a RNA-dependent RNA polymerase locus from 123 orthocoronaviruses isolated from birds and bats, including those in New Zealand, which were geographically isolated from other bats around 35 million years ago. We used this age, as well as the age of the avian-mammals split, to calibrate the molecular clocks, under the assumption that these ages are applicable to the analyzed viruses. We found that the time to the most recent ancestor common for all orthocoronaviruses is likely 150 or more million years, supporting clock analyses that account for selection.


Assuntos
Aves/virologia , Quirópteros/virologia , Infecções por Coronaviridae/virologia , Coronaviridae , Genoma Viral , Animais , Coronaviridae/classificação , Coronaviridae/genética , Evolução Molecular , Nova Zelândia/epidemiologia
6.
Philos Trans R Soc Lond B Biol Sci ; 376(1833): 20200186, 2021 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-34304594

RESUMO

It is a broadly observed pattern that the non-recombining regions of sex-limited chromosomes (Y and W) accumulate more repeats than the rest of the genome, even in species like birds with a low genome-wide repeat content. Here, we show that in birds with highly heteromorphic sex chromosomes, the W chromosome has a transposable element (TE) density of greater than 55% compared to the genome-wide density of less than 10%, and contains over half of all full-length (thus potentially active) endogenous retroviruses (ERVs) of the entire genome. Using RNA-seq and protein mass spectrometry data, we were able to detect signatures of female-specific ERV expression. We hypothesize that the avian W chromosome acts as a refugium for active ERVs, probably leading to female-biased mutational load that may influence female physiology similar to the 'toxic-Y' effect in Drosophila males. Furthermore, Haldane's rule predicts that the heterogametic sex has reduced fertility in hybrids. We propose that the excess of W-linked active ERVs over the rest of the genome may be an additional explanatory variable for Haldane's rule, with consequences for genetic incompatibilities between species through TE/repressor mismatches in hybrids. Together, our results suggest that the sequence content of female-specific W chromosomes can have effects far beyond sex determination and gene dosage. This article is part of the theme issue 'Challenging the paradigm in sex chromosome evolution: empirical and theoretical insights with a focus on vertebrates (Part II)'.


Assuntos
Aves/genética , Retrovirus Endógenos/fisiologia , Taxa de Mutação , Cromossomos Sexuais , Animais , Aves/virologia , Feminino , Fertilidade , Masculino , Fatores Sexuais , Especificidade da Espécie
7.
Emerg Microbes Infect ; 10(1): 1503-1506, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34260340

RESUMO

Eleven highly pathogenic avian influenza H5N8 viruses (clade 2.3.4.4b) were detected in migratory birds in Central China between November and December 2020, which were highly homologous to strains isolated in Europe from October to December 2020. Phylogenetic analysis indicated that the strains in the study possibly spread from Siberia by migratory birds. In this study, we found H5N8 virus infection in migratory birds could cause severe pathological damage and high viral load in multiple organs.


Assuntos
Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Influenza Aviária/virologia , Migração Animal , Animais , Animais Selvagens/classificação , Animais Selvagens/fisiologia , Animais Selvagens/virologia , Aves/classificação , Aves/fisiologia , Aves/virologia , China , Vírus da Influenza A Subtipo H5N8/classificação , Vírus da Influenza A Subtipo H5N8/genética , Influenza Aviária/fisiopatologia , Filogenia
8.
Viruses ; 13(7)2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209881

RESUMO

The viral family Coronaviridae comprises four genera, termed Alpha-, Beta-, Gamma-, and Deltacoronavirus. Recombination events have been described in many coronaviruses infecting humans and other animals. However, formal analysis of the recombination patterns, both in terms of the involved genome regions and the extent of genetic divergence between partners, are scarce. Common methods of recombination detection based on phylogenetic incongruences (e.g., a phylogenetic compatibility matrix) may fail in cases where too many events diminish the phylogenetic signal. Thus, an approach comparing genetic distances in distinct genome regions (pairwise distance deviation matrix) was set up. In alpha, beta, and delta-coronaviruses, a low incidence of recombination between closely related viruses was evident in all genome regions, but it was more extensive between the spike gene and other genome regions. In contrast, avian gammacoronaviruses recombined extensively and exist as a global cloud of genes with poorly corresponding genetic distances in different parts of the genome. Spike, but not other structural proteins, was most commonly exchanged between coronaviruses. Recombination patterns differed between coronavirus genera and corresponded to the modular structure of the spike: recombination traces were more pronounced between spike domains (N-terminal and C-terminal parts of S1 and S2) than within domains. The variability of possible recombination events and their uneven distribution over the genome suggest that compatibility of genes, rather than mechanistic or ecological limitations, shapes recombination patterns in coronaviruses.


Assuntos
Coronavirus/classificação , Coronavirus/genética , Evolução Molecular , Variação Genética , Genoma Viral , Recombinação Genética , Animais , Aves/virologia , Infecções por Coronavirus/virologia , Filogenia , Proteínas Virais/genética
9.
Nature ; 592(7854): 340-343, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33854246
10.
Viruses ; 13(3)2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33809549

RESUMO

During October 2020-January 2021, we isolated a total of 67 highly pathogenic avian influenza (HPAI) H5N8 viruses from wild birds and outbreaks in poultry in South Korea. We sequenced the isolates and performed phylogenetic analysis of complete genome sequences to determine the origin, evolution, and spread patterns of these viruses. Phylogenetic analysis of the hemagglutinin (HA) gene showed that all the isolates belong to H5 clade 2.3.4.4 subgroup B (2.3.4.4b) and form two distinct genetic clusters, G1 and G2. The cluster G1 was closely related to the 2.3.4.4b H5N8 HPAI viruses detected in Europe in early 2020, while the cluster G2 had a close genetic relationship with the 2.3.4.4b H5N8 viruses that circulated in Europe in late 2020. A total of seven distinct genotypes were identified, including five novel reassortants carrying internal genes of low pathogenic avian influenza viruses. Our Bayesian discrete trait phylodynamic analysis between host types suggests that the viruses initially disseminated from migratory waterfowl to domestic duck farms in South Korea. Subsequently, domestic duck farms most likely contributed to the transmission of HPAI viruses to chicken and minor poultry farms, highlighting the need for enhanced, high levels of biosecurity measures at domestic duck farms to effectively prevent the introduction and spread of HPAI.


Assuntos
Aves/virologia , Surtos de Doenças/veterinária , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Influenza Aviária/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Aves Domésticas/virologia , Animais , Vírus Reordenados , República da Coreia/epidemiologia
11.
Int J Infect Dis ; 106: 386-394, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33857607

RESUMO

OBJECTIVES: From 2013 to 2017, the avian influenza A (H7N9) virus frequently infected people in China, which seriously affected the public health of society. This study aimed to analyze the spatial characteristics of human infection with the H7N9 virus in China and assess the risk areas of the epidemic. METHODS: Using kernel density estimation, standard deviation ellipse analysis, spatial and temporal scanning cluster analysis, and Pearson correlation analysis, the spatial characteristics and possible risk factors of the epidemic were studied. Meteorological factors, time (month), and environmental factors were combined to establish an epidemic risk assessment proxy model to assess the risk range of an epidemic. RESULTS: The epidemic situation was significantly correlated with atmospheric pressure, temperature, and daily precipitation (P < 0.05), and there were six temporal and spatial clusters. The fitting accuracy of the epidemic risk assessment agent-based model for lower-risk, low-risk, medium-risk, and high-risk was 0.795, 0.672, 0.853, 0.825, respectively. CONCLUSIONS: This H7N9 epidemic was found to have more outbreaks in winter and spring. It gradually spread to the inland areas of China. This model reflects the risk areas of human infection with the H7N9 virus.


Assuntos
Aves/virologia , Subtipo H7N9 do Vírus da Influenza A/fisiologia , Influenza Humana/epidemiologia , Modelos Estatísticos , Animais , China/epidemiologia , Análise por Conglomerados , Surtos de Doenças , Humanos , Medição de Risco , Fatores de Risco , Estações do Ano , Análise Espaço-Temporal
12.
Emerg Microbes Infect ; 10(1): 565-577, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33666526

RESUMO

ABSTRACTSeveral subtypes of avian influenza (AI) viruses have caused human infections in recent years; however, there is a severe knowledge gap regarding the capacity of wild bird viruses to infect mammals. To assess the risk of mammalian infection by AI viruses from their natural reservoirs, a panel of isolates from 34 wild birds was examined in animal models. All selected AI virus subtypes were found to predominantly possess Eurasian lineage, although reassortment with North American lineage AI viruses was also noted in some isolates. When used to infect chickens, 20 AI isolates could be recovered from oropharyngeal swabs at 5 days post-infection (dpi) without causing significant morbidity. Similarly, mild to no observable disease was observed in mice infected with these viruses although the majority replicated efficiently in murine lungs. As expected, wild bird AI isolates were found to recognize avian-like receptors, while a few strains also exhibited detectable human-like receptor binding. Selected strains were further tested in ferrets, and 15 out of 20 were found to shed the virus in the upper respiratory tract until 5 dpi. Overall, we demonstrate that a diversity of low-pathogenic AI viruses carried by wild migratory birds have the capacity to infect land-based poultry and mammalian hosts while causing minimal signs of clinical disease. This study reiterates that there is a significant capacity for interspecies transmission of AI viruses harboured by wild aquatic birds. Thus, these viruses pose a significant threat to human health underscoring the need for continued surveillance.


Assuntos
Aves/virologia , Furões/virologia , Vírus da Influenza A/genética , Vírus da Influenza A/patogenicidade , Influenza Aviária/virologia , Ligação Viral , Replicação Viral , Animais , Animais Selvagens/virologia , Embrião de Galinha , Fezes/virologia , Feminino , Hemaglutininas/genética , Hemaglutininas/metabolismo , Humanos , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/epidemiologia , Influenza Aviária/transmissão , Pulmão/virologia , Mamíferos/virologia , Camundongos , Camundongos Endogâmicos BALB C , Modelos Animais , Neuraminidase/genética , Neuraminidase/metabolismo , RNA Viral , Receptores Virais/metabolismo , República da Coreia/epidemiologia
13.
Viruses ; 13(3)2021 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-33668224

RESUMO

Japanese encephalitis (JE) is a vaccine-preventable disease caused by the Japanese encephalitis virus (JEV), which is primarily prevalent in Asia. JEV is a Flavivirus, classified into a single serotype with five genetically distinct genotypes (I, II, III, IV, and V). JEV genotype III (GIII) had been the most dominant strain and caused numerous outbreaks in the JEV endemic countries until 1990. However, recent data shows the emergence of JEV genotype I (GI) as a dominant genotype and it is gradually displacing GIII. The exact mechanism of this genotype displacement is still unclear. The virus can replicate in mosquito vectors and vertebrate hosts to maintain its zoonotic life cycle; pigs and aquatic wading birds act as an amplifying/reservoir hosts, and the humans and equines are dead-end hosts. The important role of pigs as an amplifying host for the JEV is well known. However, the influence of other domestic animals, especially birds, that live in high abundance and close proximity to the human is not well studied. Here, we strive to briefly highlight the role of birds in the JEV zoonotic transmission, discovery of birds as a natural reservoirs and amplifying host for JEV, species of birds susceptible to the JEV infection, and the proposed effect of JEV on the poultry industry in the future, a perspective that has been neglected for a long time. We also discuss the recent in vitro and in vivo studies that show that the newly emerged GI viruses replicated more efficiently in bird-derived cells and ducklings/chicks than GIII, and an important role of birds in the JEV genotype shift from GIII to GI.


Assuntos
Aves/virologia , Vírus da Encefalite Japonesa (Espécie)/patogenicidade , Encefalite Japonesa/transmissão , Encefalite Japonesa/virologia , Mosquitos Vetores/virologia , Animais , Genótipo , Humanos
14.
Viruses ; 13(3)2021 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-33673635

RESUMO

Wild aquatic birds, a natural reservoir of avian influenza viruses (AIVs), transmit AIVs to poultry farms, causing huge economic losses. Therefore, the prevalence and genetic characteristics of AIVs isolated from wild birds in South Korea from October 2019 to March 2020 were investigated and analyzed. Fresh avian fecal samples (3256) were collected by active monitoring of 11 wild bird habitats. Twenty-eight AIVs were isolated. Seven HA and eight NA subtypes were identified. All AIV hosts were Anseriformes species. The HA cleavage site of 20 representative AIVs was encoded by non-multi-basic amino acid sequences. Phylogenetic analysis of the eight segment genes of the AIVs showed that most genes clustered within the Eurasian lineage. However, the HA gene of H10 viruses and NS gene of four viruses clustered within the American lineage, indicating intercontinental reassortment of AIVs. Representative viruses likely to infect mammals were selected and evaluated for pathogenicity in mice. JB21-58 (H5N3), JB42-93 (H9N2), and JB32-81 (H11N2) were isolated from the lungs, but JB31-69 (H11N9) was not isolated from the lungs until the end of the experiment at 14 dpi. None of infected mice showed clinical sign and histopathological change in the lung. In addition, viral antigens were not detected in lungs of all mice at 14 dpi. These data suggest that LPAIVs derived from wild birds are unlikely to be transmitted to mammals. However, because LPAIVs can reportedly infect mammals, including humans, continuous surveillance and monitoring of AIVs are necessary, despite their low pathogenicity.


Assuntos
Aves/virologia , Influenza Aviária/genética , Animais , Animais Selvagens/virologia , Feminino , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H9N2/genética , Pulmão/virologia , Camundongos , Camundongos Endogâmicos BALB C , Filogenia , República da Coreia
16.
Trends Microbiol ; 29(7): 573-581, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33712334

RESUMO

Emerging zoonotic diseases exert a significant burden on human health and have considerable socioeconomic impact worldwide. In Asia, live animals as well as animal products are commonly sold in informal markets. The interaction of humans, live domestic animals for sale, food products, and wild and scavenging animals, creates a risk for emerging infectious diseases. Such markets have been in the spotlight as sources of zoonotic viruses, for example, avian influenza viruses and coronaviruses, Here, we bring data together on the global impact of live and wet markets on the emergence of zoonotic diseases. We discuss how benefits can be maximized and risks minimized and conclude that current regulations should be implemented or revised, to mitigate the risk of new diseases emerging in the future.


Assuntos
Comércio/normas , Doenças Transmissíveis Emergentes/etiologia , Alimentos , Infecções por Orthomyxoviridae/transmissão , Zoonoses/transmissão , Animais , Ásia , Aves/virologia , COVID-19/transmissão , COVID-19/virologia , Comércio/legislação & jurisprudência , Comércio/métodos , Doenças Transmissíveis Emergentes/prevenção & controle , Doenças Transmissíveis Emergentes/virologia , Aglomeração , Humanos , Influenza Aviária/transmissão , Influenza Aviária/virologia , Influenza Humana/virologia , Infecções por Orthomyxoviridae/virologia , Zoonoses/classificação , Zoonoses/virologia
17.
Viruses ; 13(2)2021 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-33573231

RESUMO

Highly pathogenic avian influenza (HPAI) outbreaks in wild birds and poultry are no longer a rare phenomenon in Europe. In the past 15 years, HPAI outbreaks-in particular those caused by H5 viruses derived from the A/Goose/Guangdong/1/1996 lineage that emerged in southeast Asia in 1996-have been occuring with increasing frequency in Europe. Between 2005 and 2020, at least ten HPAI H5 incursions were identified in Europe resulting in mass mortalities among poultry and wild birds. Until 2009, the HPAI H5 virus outbreaks in Europe were caused by HPAI H5N1 clade 2.2 viruses, while from 2014 onwards HPAI H5 clade 2.3.4.4 viruses dominated outbreaks, with abundant genetic reassortments yielding subtypes H5N1, H5N2, H5N3, H5N4, H5N5, H5N6 and H5N8. The majority of HPAI H5 virus detections in wild and domestic birds within Europe coincide with southwest/westward fall migration and large local waterbird aggregations during wintering. In this review we provide an overview of HPAI H5 virus epidemiology, ecology and evolution at the interface between poultry and wild birds based on 15 years of avian influenza virus surveillance in Europe, and assess future directions for HPAI virus research and surveillance, including the integration of whole genome sequencing, host identification and avian ecology into risk-based surveillance and analyses.


Assuntos
Animais Selvagens/virologia , Aves/virologia , Vírus da Influenza A/fisiologia , Influenza Aviária/virologia , Migração Animal , Animais , Animais Selvagens/fisiologia , Aves/fisiologia , Europa (Continente) , Vírus da Influenza A/genética , Vírus da Influenza A/patogenicidade , Influenza Aviária/fisiopatologia
18.
Sci Rep ; 11(1): 3126, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33542302

RESUMO

Influenza H7N9 virus continues to cause infections in humans and represents a significant pandemic risk. During the most recent 5th epidemic wave in 2016/17 two distinct lineages with increased human infections and wider geographical spread emerged. In preparation for any future adaptations, broadly reactive antibodies against H7N9 are required for surveillance, therapy and prophylaxis. In this study we have isolated a panel of nanobodies (Nbs) with broad reactivity across H7 influenza strains, including H7N9 strains between 2013 and 2017. We also describe Nbs capable of distinguishing between the most recent high and low pathogenicity Yangtze River Delta lineage H7N9 strains. Nanobodies were classified into 5 distinct groups based on their epitope footprint determined using yeast display and mutational scanning. The epitope footprint of Nbs capable of distinguishing high pathogenic (HP) A/Guangdong/17SF003/2016 from low pathogenic (LP) A/Hong Kong/125/2017 (H7N9) were correlated to natural sequence divergence in the head domain at lysine 164. Several Nbs binding to the head domain were capable of viral neutralisation. The potency of one nanobody NB7-14 could be increased over 1000-fold to 113 pM by linking two Nbs together. Nbs specific for distinct epitopes on H7N9 may be useful for surveillance or therapy in human or veterinary settings.


Assuntos
Anticorpos Neutralizantes/biossíntese , Anticorpos Antivirais/biossíntese , Epitopos/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Subtipo H7N9 do Vírus da Influenza A/efeitos dos fármacos , Biblioteca de Peptídeos , Anticorpos de Domínio Único/biossíntese , Sequência de Aminoácidos , Animais , Anticorpos Neutralizantes/isolamento & purificação , Anticorpos Antivirais/isolamento & purificação , Sítios de Ligação , Aves/virologia , Epitopos/química , Epitopos/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/imunologia , Influenza Aviária/imunologia , Influenza Aviária/prevenção & controle , Influenza Aviária/transmissão , Influenza Aviária/virologia , Influenza Humana/imunologia , Influenza Humana/prevenção & controle , Influenza Humana/transmissão , Influenza Humana/virologia , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Anticorpos de Domínio Único/isolamento & purificação
19.
Arch Virol ; 166(4): 1197-1201, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33598814

RESUMO

Waterfowl are considered to be the natural hosts of avian influenza virus. In 2017, two reassortant highly pathogenic H5N6 avian influenza viruses of clade 2.3.4.4, subclade II, were identified in wild birds in eastern China. Genome sequencing and phylogenetic and antigenicity analysis showed that the viruses originated from multiple reassortments. To evaluate their pathogenicity in mammals, 15 BALB/c mice were infected with these viruses, and survival and weight loss were monitored for 14 days. Infection was associated with moderate pathogenicity in the mice, and the viruses could replicate in the lungs without prior adaptation. Thus, the existence of these viruses poses a continuous threat to both birds and humans.


Assuntos
Animais Selvagens/virologia , Aves/virologia , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/virologia , Vírus Reordenados/isolamento & purificação , Animais , China/epidemiologia , Variação Genética , Genoma Viral/genética , Genótipo , Vírus da Influenza A/genética , Vírus da Influenza A/imunologia , Vírus da Influenza A/patogenicidade , Camundongos , Camundongos Endogâmicos BALB C , Filogenia , RNA Viral/genética , Vírus Reordenados/genética , Vírus Reordenados/imunologia , Vírus Reordenados/patogenicidade , Proteínas Virais/genética , Proteínas Virais/imunologia
20.
Sci Rep ; 11(1): 3491, 2021 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-33568682

RESUMO

To understand the dynamics of a pathogen in an animal population, one must assess how the infection status of individuals changes over time. With wild animals, this can be very challenging because individuals can be difficult to trap and sample, even more so since they are tested with imperfect diagnostic techniques. Multi-event capture-recapture models allow analysing longitudinal capture data of individuals whose infection status is assessed using imperfect tests. In this study, we used a two-year dataset from a longitudinal field study of peridomestic wild bird populations in the United Arab Emirates during which thousands of birds from various species were captured, sampled and tested for Newcastle disease virus exposure using a serological test. We developed a multi-event capture-recapture model to estimate important demographic and epidemiological parameters of the disease. The modelling outputs provided important insights into the understanding of Newcastle disease dynamics in peridomestics birds, which varies according to ecological and epidemiological parameters, and useful information in terms of surveillance strategies. To our knowledge, this study is the first attempt to model the dynamics of Newcastle disease in wild bird populations by combining longitudinal capture data and serological test results. Overall, it showcased that multi-event capture-recapture models represent a suitable method to analyse imperfect capture data and make reliable inferences on infectious disease dynamics in wild populations.


Assuntos
Aves/virologia , Doenças Transmissíveis/virologia , Doença de Newcastle/virologia , Vírus da Doença de Newcastle/patogenicidade , Animais , Animais Selvagens , Dinâmica Populacional , Emirados Árabes Unidos
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