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1.
Viruses ; 14(3)2022 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-35336936

RESUMO

Low pathogenic H9N2 avian influenza (LPAI H9N2) is considered one of the most important diseases found in poultry (broiler, laying hens, breeding chickens, and turkeys). This infection causes considerable economic losses. The objective of this work was to monitor and assess the presence of avian influenza virus (AIV) H9N2 in eight different regions of Morocco using real-time RT-PCR, and to assess the phylogenetic and molecular evolution of the H9N2 viruses between 2016 and 2019. Field samples were collected from 108 farms suspected of being infected with LPAI H9N2 virus. Samples were analyzed using H9N2-specific real-time RT-PCR. Highly positive samples were subjected to virus isolation and seven isolates were fully sequenced. Low pathogenic H9N2 avian influenza virus was introduced in Morocco in 2016. We show that in 2018-2019, the virus was still present irrespective of vaccination status. Phylogenetic and molecular analyses showed mutations related to virulence, although our viruses were related to 2016 Moroccan viruses and grouped in the G1 lineage. Specific amino acid substitutions were identified in Moroccan H9N2 viruses that are believed to lead to increased resistance to antiviral drugs.


Assuntos
Vírus da Influenza A Subtipo H9N2 , Influenza Aviária , Doenças das Aves Domésticas , Animais , Galinhas , Feminino , Influenza Aviária/epidemiologia , Marrocos/epidemiologia , Filogenia , Doenças das Aves Domésticas/epidemiologia
2.
Microorganisms ; 10(3)2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35336170

RESUMO

In Egypt, the endemicity of avian influenza viruses is a serious concern. Since 2016, several outbreaks of H5N8 have been recorded among domestic poultry in various areas of the country. Active surveillance of domestic poultry across several governorates in Egypt from 2017 to 2021 detected at least six genotypes of Highly Pathogenic Avian Influenza (HPAI) H5N8 viruses with evidence of partial or complete annual replacement of dominant strains. Although all Egyptian H5N8 viruses had clade 2.3.4.4b hemagglutinin (HA) genes, the remaining viral gene segments were from multiple geographic origins, indicating that the H5N8 isolates resulted from multiple introductions. Mutations in the viral proteins associated with pathogenicity and antiviral drug resistance were detected. Some mutations in the HA resulted in antigenic drift. Heterogeneity in circulating H5N8 HPAI threatens poultry production and public health.

3.
Nat Microbiol ; 6(11): 1455-1465, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34702977

RESUMO

Understanding the evolutionary adaptations that enable avian influenza viruses to transmit in mammalian hosts could allow better detection of zoonotic viruses with pandemic potential. We applied ancestral sequence reconstruction to gain viruses representing different adaptive stages of the European avian-like (EA) H1N1 swine influenza virus as it transitioned from avian to swine hosts since 1979. Ancestral viruses representing the avian-like precursor virus and EA swine influenza viruses from 1979-1983, 1984-1987 and 1988-1992 were reconstructed and characterized. Glycan-binding analyses showed stepwise changes in the haemagglutinin receptor-binding specificity of the EA swine influenza viruses-that is, from recognition of both α2,3- and α2,6-linked sialosides to recognition of α2,6-linked sialosides only; however, efficient transmission in piglets was enabled by adaptive changes in the viral polymerase protein and nucleoprotein, which have been fixed since 1983. PB1-Q621R and NP-R351K increased viral replication and transmission in piglets when introduced into the 1979-1983 ancestral virus that lacked efficient transmissibility. The stepwise adaptation of an avian influenza virus to a mammalian host suggests that there may be opportunities to intervene and prevent interspecies jumps through strategic coordination of surveillance and risk assessment activities.


Assuntos
Adaptação Fisiológica , Vírus da Influenza A Subtipo H1N1/fisiologia , Influenza Aviária/virologia , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/virologia , Animais , Aves , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Vírus da Influenza A Subtipo H1N1/classificação , Vírus da Influenza A Subtipo H1N1/genética , Influenza Aviária/transmissão , Infecções por Orthomyxoviridae/metabolismo , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/virologia , Filogenia , Polissacarídeos/química , Polissacarídeos/metabolismo , Receptores Virais/química , Receptores Virais/metabolismo , Suínos , Doenças dos Suínos/metabolismo , Doenças dos Suínos/transmissão , Replicação Viral
4.
Viruses ; 13(4)2021 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-33918166

RESUMO

Genetic analysis of circulating avian influenza viruses (AIVs) in wild birds at different geographical regions during the same period could improve our knowledge about virus transmission dynamics in natural hosts, virus evolution as well as zoonotic potential. Here, we report the genetic and molecular characterization of H6N2 influenza viruses isolated from migratory birds in Turkey, Egypt, and Uganda during 2017-2018. The Egyptian and Turkish isolates were genetically closer to each other than they were to the virus isolated from Uganda. Our results also suggest that multiple reassortment events were involved in the genesis of the isolated viruses. All viruses contained molecular markers previously associated with increased replication and/or pathogenicity in mammals. The results of this study indicate that H6N2 viruses carried by migratory birds on the West Asian/East African and Mediterranean/Black Sea flyways have the potential to transmit to mammals including humans. Additionally, adaptation markers in these viruses indicate the potential risk for poultry, which also increases the possibility of human exposure to these viruses.


Assuntos
Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Aviária/virologia , Filogenia , Vírus Reordenados/genética , Migração Animal , Animais , Animais Selvagens/virologia , Galinhas/virologia , Egito , Genoma Viral , Humanos , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/transmissão , Aves Domésticas/virologia , Turquia , Uganda
5.
Emerg Microbes Infect ; 10(1): 753-761, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33754959

RESUMO

Sub-Saharan Africa was historically considered an animal influenza cold spot, with only sporadic highly pathogenic H5 outbreaks detected over the last 20 years. However, in 2017, low pathogenic avian influenza A(H9N2) viruses were detected in poultry in Sub-Saharan Africa. Molecular, phylogenetic, and antigenic characterization of isolates from Benin, Togo, and Uganda showed that they belonged to the G1 lineage. Isolates from Benin and Togo clustered with viruses previously described in Western Africa, whereas viruses from Uganda were genetically distant and clustered with viruses from the Middle East. Viruses from Benin exhibited decreased cross-reactivity with those from Togo and Uganda, suggesting antigenic drift associated with reduced replication in Calu-3 cells. The viruses exhibited mammalian adaptation markers similar to those of the human strain A/Senegal/0243/2019 (H9N2). Therefore, viral genetic and antigenic surveillance in Africa is of paramount importance to detect further evolution or emergence of new zoonotic strains.


Assuntos
Vírus da Influenza A Subtipo H9N2/genética , Vírus da Influenza A Subtipo H9N2/imunologia , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , África ao Sul do Saara , Animais , Anticorpos Antivirais/imunologia , Variação Antigênica , Galinhas/virologia , Reações Cruzadas , Evolução Molecular , Humanos , Vírus da Influenza A Subtipo H9N2/patogenicidade , Vírus da Influenza A Subtipo H9N2/fisiologia , Influenza Humana/virologia , Filogenia , Virulência , Replicação Viral
6.
Nat Commun ; 12(1): 1203, 2021 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-33619277

RESUMO

Influenza A virus infection in swine impacts the agricultural industry in addition to its zoonotic potential. Here, we utilize epigraph, a computational algorithm, to design a universal swine H3 influenza vaccine. The epigraph hemagglutinin proteins are delivered using an Adenovirus type 5 vector and are compared to a wild type hemagglutinin and the commercial inactivated vaccine, FluSure. In mice, epigraph vaccination leads to significant cross-reactive antibody and T-cell responses against a diverse panel of swH3 isolates. Epigraph vaccination also reduces weight loss and lung viral titers in mice after challenge with three divergent swH3 viruses. Vaccination studies in swine, the target species for this vaccine, show stronger levels of cross-reactive antibodies and T-cell responses after immunization with the epigraph vaccine compared to the wild type and FluSure vaccines. In both murine and swine models, epigraph vaccination shows superior cross-reactive immunity that should be further investigated as a universal swH3 vaccine.


Assuntos
Algoritmos , Reações Cruzadas/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Imunidade , Vírus da Influenza A/imunologia , Vacinas contra Influenza/imunologia , Animais , Formação de Anticorpos/imunologia , Epitopos/imunologia , Feminino , Humanos , Influenza Humana/sangue , Influenza Humana/imunologia , Influenza Humana/virologia , Pulmão/patologia , Pulmão/virologia , Masculino , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/sangue , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/virologia , Suínos , Linfócitos T/imunologia , Vacinação , Perda de Peso
7.
J Virol ; 94(18)2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32611750

RESUMO

Since its detection in swine, influenza D virus (IDV) has been shown to be present in multiple animal hosts, and bovines have been identified as its natural reservoir. However, it remains unclear how IDVs emerge, evolve, spread, and maintain in bovine populations. Through multiple years of virological and serological surveillance in a single order-buyer cattle facility in Mississippi, we showed consistently high seroprevalence of IDVs in cattle and recovered a total of 32 IDV isolates from both healthy and sick animals, including those with antibodies against IDV. Genomic analyses of these isolates along with those isolated from other areas showed that active genetic reassortment occurred in IDV and that five reassortants were identified in the Mississippian facility. Two antigenic groups were identified through antigenic cartography analyses for these 32 isolates and representative IDVs from other areas. Remarkably, existing antibodies could not protect cattle from experimental reinfection with IDV. Additional phenotypic analyses demonstrated variations in growth dynamics and pathogenesis in mice between viruses independent of genomic constellation. In summary, this study suggests that, in addition to epidemiological factors, the ineffectiveness of preexisting immunity and cocirculation of a diverse viral genetic pool could facilitate its high prevalence in animal populations.IMPORTANCE Influenza D viruses (IDVs) are panzootic in multiple animal hosts, but the underlying mechanism is unclear. Through multiple years of surveillance in the same order-buyer cattle facility, 32 IDV isolates were recovered from both healthy and sick animals, including those with evident antibodies against IDV. Active reassortment occurred in the cattle within this facility and in those across other areas, and multiple reassortants cocirculated in animals. These isolates are shown with a large extent of phenotypic diversity in replication efficiency and pathogenesis but little in antigenic properties. Animal experiments demonstrated that existing antibodies could not protect cattle from experimental reinfection with IDV. This study suggests that, in addition to epidemiological factors, limited protection from preexisting immunity against IDVs in cattle herds and cocirculation of a diverse viral genetic pool likely facilitate the high prevalence of IDVs in animal populations.


Assuntos
Anticorpos Antivirais/sangue , Proteção Cruzada , Genoma Viral , Infecções por Orthomyxoviridae/epidemiologia , Vírus Reordenados/imunologia , Thogotovirus/imunologia , Animais , Bovinos , Monitoramento Epidemiológico , Fazendas , Variação Genética , Genótipo , Hospitais Veterinários , Imunidade Inata , Camundongos , Mississippi/epidemiologia , Tipagem Molecular , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Filogenia , Vírus Reordenados/classificação , Vírus Reordenados/genética , Vírus Reordenados/patogenicidade , Estudos Soroepidemiológicos , Thogotovirus/classificação , Thogotovirus/genética , Thogotovirus/patogenicidade , Replicação Viral
9.
Influenza Other Respir Viruses ; 13(6): 622-626, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31478603

RESUMO

In late 2017, increased mortality was detected in chicken farms in Algeria undergoing A(H9N2) influenza outbreaks. Analysis of viruses isolated from affected farms showed that they were monophyletic, were of the G1 hemagglutinin (HA) lineage, and were antigenically and genetically similar to viruses detected contemporaneously in other countries in Northern Africa and the Middle East. The virus was able to spread via contact transmission between ferrets but did not cause disease in intravenously inoculated chickens.


Assuntos
Surtos de Doenças/veterinária , Vírus da Influenza A Subtipo H9N2/fisiologia , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Argélia/epidemiologia , Animais , Galinhas , Fazendas , Furões , Testes de Inibição da Hemaglutinação/veterinária , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A Subtipo H9N2/classificação , Vírus da Influenza A Subtipo H9N2/genética , Vírus da Influenza A Subtipo H9N2/imunologia , Influenza Aviária/diagnóstico , Influenza Aviária/transmissão , Neuraminidase/genética , Filogenia , Carga Viral/veterinária , Proteínas Virais/genética
10.
Proc Natl Acad Sci U S A ; 114(42): 11217-11222, 2017 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-28874549

RESUMO

North American wild birds are an important reservoir of influenza A viruses, yet the potential of viruses in this reservoir to transmit and cause disease in mammals is not well understood. Our surveillance of avian influenza viruses (AIVs) at Delaware Bay, USA, revealed a group of similar H1N1 AIVs isolated in 2009, some of which were airborne-transmissible in the ferret model without prior adaptation. Comparison of the genomes of these viruses revealed genetic markers of airborne transmissibility in the Polymerase Basic 2 (PB2), PB1, PB1-F2, Polymerase Acidic-X (PA-X), Nonstructural Protein 1 (NS1), and Nuclear Export Protein (NEP) genes. We studied the role of NS1 in airborne transmission and found that NS1 mutants that were not airborne-transmissible caused limited tissue pathology in the upper respiratory tract (URT). Viral maturation was also delayed, evident as strong intranuclear staining and little virus at the mucosa. Our study of this naturally occurring constellation of genetic markers has provided insights into the poorly understood phenomenon of AIV airborne transmissibility by revealing a role for NS1 and characteristics of viral replication in the URT that were associated with airborne transmission. The transmissibility of these viruses further highlights the pandemic potential of AIVs in the wild bird reservoir and the need to maintain surveillance.


Assuntos
Charadriiformes/virologia , Vírus da Influenza A Subtipo H1N1/patogenicidade , Infecções por Orthomyxoviridae/transmissão , Animais , Embrião de Galinha , Vetores de Doenças , Furões , Vírus da Influenza A Subtipo H1N1/genética , Masculino , Sistema Respiratório/virologia , Replicação Viral
11.
J Gen Virol ; 98(6): 1232-1244, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28631606

RESUMO

Among the diverse clades of highly pathogenic avian influenza (HPAI) H5N1 viruses of the goose/Guangdong lineage, only a few have been able to spread across continents: clade 2.2 viruses spread from China to Europe and into Africa in 2005-2006, clade 2.3.2.1 viruses spread from China to Eastern Europe in 2009-2010 and clade 2.3.4.4 viruses of the H5Nx subtype spread from China to Europe and North America in 2014/2015. While the poultry trade and wild-bird migration have been implicated in the spread of HPAI H5N1 viruses, it has been proposed that robust virus-shedding by wild ducks in the absence of overt clinical signs may have contributed to the wider dissemination of the clade 2.2, 2.3.2.1 and 2.3.4.4 viruses. Here we determined the phenotype of two divergent viruses from clade 2.3.2.1, a clade that spread widely, and two divergent viruses from clade 2.3.4, a clade that was constrained to Southeast Asia, in young (ducklings) and adult (juvenile) mallard ducks. We found that the virus-shedding magnitude and duration, transmission pattern and pathogenicity of the viruses in young and adult mallard ducks were largely independent of the virus clade. A clade-specific pattern could only be detected in terms of cumulative virus shedding, which was higher with clade 2.3.2.1 than with clade 2.3.4 viruses in juvenile mallards, but not in ducklings. The ability of clade 2.3.2.1c A/common buzzard/Bulgaria/38 WB/2010-like viruses to spread cross-continentally may, therefore, have been strain-specific or independent of phenotype in wild ducks.


Assuntos
Genótipo , Virus da Influenza A Subtipo H5N1/patogenicidade , Influenza Aviária/patologia , Influenza Aviária/virologia , Eliminação de Partículas Virais , África , Animais , Ásia , Patos , Europa (Continente) , Virus da Influenza A Subtipo H5N1/classificação , Virus da Influenza A Subtipo H5N1/genética , América do Norte , Fenótipo
12.
J Virol ; 90(17): 7647-56, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27279619

RESUMO

UNLABELLED: We have previously shown that 11 patients became naturally coinfected with seasonal H1N1 (A/H1N1) and pandemic H1N1 (pdm/H1N1) during the Southern hemisphere winter of 2009 in New Zealand. Reassortment of influenza A viruses is readily observed during coinfection of host animals and in vitro; however, reports of reassortment occurring naturally in humans are rare. Using clinical specimen material, we show reassortment between the two coinfecting viruses occurred with high likelihood directly in one of the previously identified patients. Despite the lack of spread of these reassortants in the community, we did not find them to be attenuated in several model systems for viral replication and virus transmission: multistep growth curves in differentiated human bronchial epithelial cells revealed no growth deficiency in six recovered reassortants compared to A/H1N1 and pdm/H1N1 isolates. Two reassortant viruses were assessed in ferrets and showed transmission to aerosol contacts. This study demonstrates that influenza virus reassortants can arise in naturally coinfected patients. IMPORTANCE: Reassortment of influenza A viruses is an important driver of virus evolution, but little has been done to address humans as hosts for the generation of novel influenza viruses. We show here that multiple reassortant viruses were generated during natural coinfection of a patient with pandemic H1N1 (2009) and seasonal H1N1 influenza A viruses. Though apparently fit in model systems, these reassortants did not become established in the wider population, presumably due to herd immunity against their seasonal H1 antigen.


Assuntos
Coinfecção/virologia , Vírus da Influenza A Subtipo H1N1/crescimento & desenvolvimento , Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/virologia , Vírus Reordenados/crescimento & desenvolvimento , Vírus Reordenados/genética , Animais , Modelos Animais de Doenças , Células Epiteliais/virologia , Furões , Humanos , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Nova Zelândia , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/virologia , Fenótipo , Vírus Reordenados/isolamento & purificação , Virulência , Replicação Viral
13.
J Virol ; 89(21): 10891-900, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26292325

RESUMO

UNLABELLED: Human infections with avian influenza viruses are a serious public health concern. The neuraminidase (NA) inhibitors (NAIs) are the frontline anti-influenza drugs and are the major option for treatment of newly emerging influenza. Therefore, it is essential to identify the molecular markers of NAI resistance among specific NA subtypes of avian influenza viruses to help guide clinical management. NAI-resistant substitutions in NA subtypes other than N1 and N2 have been poorly studied. Here, we identified NA amino acid substitutions associated with NAI resistance among influenza viruses of N3, N7, and N9 subtypes which have been associated with zoonotic transmission. We applied random mutagenesis and generated recombinant influenza viruses carrying single or double NA substitution(s) with seven internal genes from A/Puerto Rico/8/1934 (H1N1) virus. In a fluorescence-based NA inhibition assay, we identified three categories of NA substitutions associated with reduced inhibition by NAIs (oseltamivir, zanamivir, and peramivir): (i) novel subtype-specific substitutions in or near the enzyme catalytic site (R152W, A246T, and D293N, N2 numbering), (ii) subtype-independent substitutions (E119G/V and/or D and R292K), and (iii) substitutions previously reported in other subtypes (Q136K, I222M, and E276D). Our data show that although some markers of resistance are present across NA subtypes, other subtype-specific markers can only be determined empirically. IMPORTANCE: The number of humans infected with avian influenza viruses is increasing, raising concerns of the emergence of avian influenza viruses resistant to neuraminidase (NA) inhibitors (NAIs). Since most studies have focused on NAI-resistance in human influenza viruses, we investigated the molecular changes in NA that could confer NAI resistance in avian viruses grown in immortalized monolayer cells, especially those of the N3, N7, and N9 subtypes, which have caused human infections. We identified not only numerous NAI-resistant substitutions previously reported in other NA subtypes but also several novel changes conferring reduced susceptibility to NAIs, which are subtype specific. The findings indicate that some resistance markers are common across NA subtypes, but other markers need to be determined empirically for each subtype. The study also implies that antiviral surveillance monitoring could play a critical role in the clinical management of influenza virus infection and an essential component of pandemic preparedness.


Assuntos
Resistência a Medicamentos/genética , Inibidores Enzimáticos/farmacologia , Marcadores Genéticos/genética , Vírus da Influenza A/genética , Modelos Moleculares , Neuraminidase/antagonistas & inibidores , Animais , Cães , Engenharia Genética , Humanos , Vírus da Influenza A/efeitos dos fármacos , Células Madin Darby de Rim Canino , Mutagênese , Neuraminidase/química , Especificidade da Espécie , Ensaio de Placa Viral
14.
J Virol ; 89(8): 4549-61, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25673719

RESUMO

UNLABELLED: Highly pathogenic H5N1 avian influenza viruses are associated with severe disease in humans and continue to be a pandemic threat. While vaccines are available, other approaches are required for patients that typically respond poorly to vaccination, such as the elderly and the immunocompromised. To produce a therapeutic agent that is highly efficacious at low doses and is broadly specific against antigenically drifted H5N1 influenza viruses, we developed two neutralizing monoclonal antibodies and combined them into a single bispecific Fc fusion protein (the Fc dual-affinity retargeting [FcDART] molecule). In mice, a single therapeutic or prophylactic dose of either monoclonal antibody at 2.5 mg/kg of body weight provided 100% protection against challenge with A/Vietnam/1203/04 (H5N1) or the antigenically drifted strain A/Whooper swan/Mongolia/244/05 (H5N1). In ferrets, a single 1-mg/kg prophylactic dose provided 100% protection against A/Vietnam/1203/04 challenge. FcDART was also effective, as a single 2.5-mg/kg therapeutic or prophylactic dose in mice provided 100% protection against A/Vietnam/1203/04 challenge. Antibodies bound to conformational epitopes in antigenic sites on the globular head of the hemagglutinin protein, on the basis of analysis of mutants with antibody escape mutations. While it was possible to generate escape mutants in vitro, they were neutralized by the antibodies in vivo, as mice infected with escape mutants were 100% protected after only a single therapeutic dose of the antibody used to generate the escape mutant in vitro. In summary, we have combined the antigen specificities of two highly efficacious anti-H5N1 influenza virus antibodies into a bispecific FcDART molecule, which represents a strategy to produce broadly neutralizing antibodies that are effective against antigenically diverse influenza viruses. IMPORTANCE: Highly pathogenic H5N1 avian influenza viruses are associated with severe disease in humans and are a pandemic threat. A vaccine is available, but other approaches are required for patients that typically respond poorly to vaccination, such as the elderly and the immunocompromised. The variability of the virus means that such an approach must be broad spectrum. To achieve this, we developed two antibodies that neutralize H5N1 influenza viruses. In mice, these antibodies provided complete protection against a spectrum of H5N1 influenza viruses at a single low dose. We then combined the two antibodies into a single molecule, FcDART, which combined the broad-spectrum activity and protective efficacy of both antibodies. This treatment provides a novel and effective therapeutic agent or prophylactic with activity against highly pathogenic H5N1 avian influenza viruses.


Assuntos
Anticorpos Monoclonais Murinos/uso terapêutico , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/uso terapêutico , Virus da Influenza A Subtipo H5N1/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Animais , Células CHO , Cricetinae , Cricetulus , Cães , Furões , Imunofluorescência , Células HEK293 , Testes de Inibição da Hemaglutinação , Humanos , Células Madin Darby de Rim Canino , Camundongos , Testes de Neutralização , Infecções por Orthomyxoviridae/imunologia
15.
Virology ; 468-470: 72-80, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25151061

RESUMO

The cleavage motif in the hemagglutinin (HA) protein of highly pathogenic H5 and H7 subtypes of avian influenza viruses is characterized by a peptide insertion or a multibasic cleavage site (MBCS). Here, we isolated an H4N2 virus from quails (Quail/CA12) with two additional arginines in the HA cleavage site, PEKRRTR/G, forming an MBCS-like motif. Quail/CA12 is a reassortant virus with the HA and neuraminidase (NA) gene most similar to a duck-isolated H4N2 virus, PD/CA06 with a monobasic HA cleavage site. Quail/CA12 required exogenous trypsin for efficient growth in culture and caused no clinical illness in infected chickens. Quail/CA12 had high binding preference for α2,6-linked sialic acids and showed higher replication and transmission ability in chickens and quails than PD/CA06. Although the H4N2 virus remained low pathogenic, these data suggests that the acquisition of MBCS in the field is not restricted to H5 or H7 subtypes.


Assuntos
Hemaglutininas/metabolismo , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Aviária/virologia , Codorniz , Sequência de Aminoácidos , Animais , Furões , Regulação Viral da Expressão Gênica , Hemaglutininas/química , Hemaglutininas/genética , Vírus da Influenza A/patogenicidade , Dados de Sequência Molecular , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/veterinária , Infecções por Orthomyxoviridae/virologia , Filogenia
16.
Arch Virol ; 159(11): 2861-76, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24990416

RESUMO

Avian influenza virus subtype H9N2 has been circulating in the Middle East since the 1990s. For uncertain reasons, H9N2 was not detected in Egyptian farms until the end of 2010. Circulation of H9N2 viruses in Egyptian poultry in the presence of the enzootic highly pathogenic H5N1 subtype adds a huge risk factor to the Egyptian poultry industry. In this study, 22 H9N2 viruses collected from 2011 to 2013 in Egypt were isolated and sequenced. The genomic signatures and protein sequences of these isolates were analyzed. Multiple mammalian-host-associated mutations were detected that favor transmission from avian to mammalian hosts. Other mutations related to virulence were also identified. Phylogenetic data showed that Egyptian H9N2 viruses were closely related to viruses isolated from neighboring Middle Eastern countries, and their HA gene resembled those of viruses of the G1-like lineage. No reassortment was detected with H5N1 subtypes. Serological analysis of H9N2 virus revealed antigenic conservation among Egyptian isolates. Accordingly, continuous surveillance that results in genetic and antigenic characterization of H9N2 in Egypt is warranted.


Assuntos
Antígenos Virais/genética , Evolução Molecular , Vírus da Influenza A Subtipo H9N2/genética , Vírus da Influenza A Subtipo H9N2/imunologia , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Proteínas Virais/genética , Sequência de Aminoácidos , Animais , Antígenos Virais/química , Antígenos Virais/imunologia , Egito/epidemiologia , Vírus da Influenza A Subtipo H9N2/classificação , Vírus da Influenza A Subtipo H9N2/isolamento & purificação , Influenza Aviária/epidemiologia , Dados de Sequência Molecular , Filogenia , Aves Domésticas , Doenças das Aves Domésticas/epidemiologia , Alinhamento de Sequência , Proteínas Virais/química , Proteínas Virais/imunologia
17.
Vaccine ; 32(35): 4571-4577, 2014 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-24950355

RESUMO

The H7N9 influenza virus caused significant mortality and morbidity in infected humans during an outbreak in China in 2013 stimulating vaccine development efforts. As previous H7-based vaccines have been poorly immunogenic in humans we sought to determine the immunogenic and protective properties of an inactivated whole virus vaccine derived from a 2013 H7N9 virus in ferrets. As whole virus vaccine preparations have been shown to be more immunogenic in humans, but less likely to be used, than split or surface antigen formulations, we vaccinated ferrets with a single dose of 15, 30, or 50 µg of the vaccine and subsequently challenged with wild-type A/Anhui/1/2013 (H7N9) either by direct instillation or by contact with infected animals. Although ferrets vaccinated with higher doses of vaccine had higher serum hemagglutinin inhibition (HI) titers, the titers were still low. During subsequent instillation challenge, however, ferrets vaccinated with 50 µg of vaccine showed no illness and shed significantly less virus than mock vaccinated controls. All vaccinated ferrets had lower virus loads in their lungs as compared to controls. In a separate study where unvaccinated-infected ferrets were placed in the same cage with vaccinated-uninfected ferrets, vaccination did not prevent infection in the contact ferrets, although they showed a trend of lower viral load. Overall, we conclude that inactivated whole-virus H7N9 vaccine was able to reduce the severity of infection and viral load, despite the lack of hemagglutinin-inhibiting antibodies.


Assuntos
Subtipo H7N9 do Vírus da Influenza A/imunologia , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/prevenção & controle , Índice de Gravidade de Doença , Animais , Anticorpos Antivirais/sangue , Furões , Testes de Inibição da Hemaglutinação , Vacinas contra Influenza/administração & dosagem , Pulmão/virologia , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologia , Carga Viral , Eliminação de Partículas Virais
18.
J Gen Virol ; 95(Pt 7): 1444-1463, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24722680

RESUMO

Clade 2.2 highly pathogenic H5N1 viruses have been in continuous circulation in Egyptian poultry since 2006. Their persistence caused significant genetic drift that led to the reclassification of these viruses into subclades 2.2.1 and 2.2.1.1. Here, we conducted full-genome sequence and phylogenetic analyses of 45 H5N1 isolated during 2006-2013 through systematic surveillance in Egypt, and 53 viruses that were sequenced previously and available in the public domain. Results indicated that H5N1 viruses in Egypt continue to evolve and a new distinct cluster has emerged. Mutations affecting viral virulence, pathogenicity, transmission, receptor-binding preference and drug resistance were studied. In light of our findings that H5N1 in Egypt continues to evolve, surveillance and molecular studies need to be sustained.


Assuntos
Virus da Influenza A Subtipo H5N1/classificação , Virus da Influenza A Subtipo H5N1/genética , Influenza Aviária/virologia , Aves Domésticas , Animais , Análise por Conglomerados , Egito , Genótipo , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Dados de Sequência Molecular , Filogenia , RNA Viral/genética , Análise de Sequência de DNA
19.
Emerg Infect Dis ; 20(4): 542-51, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24655395

RESUMO

Continuous circulation of influenza A(H5N1) virus among poultry in Egypt has created an epicenter in which the viruses evolve into newer subclades and continue to cause disease in humans. To detect influenza viruses in Egypt, since 2009 we have actively surveyed various regions and poultry production sectors. From August 2010 through January 2013, >11,000 swab samples were collected; 10% were positive by matrix gene reverse transcription PCR. During this period, subtype H9N2 viruses emerged, cocirculated with subtype H5N1 viruses, and frequently co-infected the same avian host. Genetic and antigenic analyses of viruses revealed that influenza A(H5N1) clade 2.2.1 viruses are dominant and that all subtype H9N2 viruses are G1-like. Cocirculation of different subtypes poses concern for potential reassortment. Avian influenza continues to threaten public and animal health in Egypt, and continuous surveillance for avian influenza virus is needed.


Assuntos
Influenza Aviária/epidemiologia , Animais , Aves/virologia , Egito/epidemiologia , Virus da Influenza A Subtipo H5N1/genética , Vírus da Influenza A Subtipo H9N2/genética
20.
Emerg Microbes Infect ; 3(2): e11, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26038508

RESUMO

Highly pathogenic H5N1 and low pathogenic H9N2 influenza viruses are endemic to poultry markets in Bangladesh and have cocirculated since 2008. H9N2 influenza viruses circulated constantly in the poultry markets, whereas highly pathogenic H5N1 viruses occurred sporadically, with peaks of activity in cooler months. Thirty highly pathogenic H5N1 influenza viruses isolated from poultry were characterized by antigenic, molecular, and phylogenetic analyses. Highly pathogenic H5N1 influenza viruses from clades 2.2.2 and 2.3.2.1 were isolated from live bird markets only. Phylogenetic analysis of the 30 H5N1 isolates revealed multiple introductions of H5N1 influenza viruses in Bangladesh. There was no reassortment between the local H9N2 influenza viruses and H5N1 genotype, despite their prolonged cocirculation. However, we detected two reassortant H5N1 viruses, carrying the M gene from the Chinese H9N2 lineage, which briefly circulated in the Bangladesh poultry markets and then disappeared. On the other hand, interclade reassortment occurred within H5N1 lineages and played a role in the genesis of the currently dominant H5N1 viruses in Bangladesh. Few 'human-like' mutations in H5N1 may account for the limited number of human cases. Antigenically, clade 2.3.2.1 H5N1 viruses in Bangladesh have evolved since their introduction and are currently mainly homogenous, and show evidence of recent antigenic drift. Although reassortants containing H9N2 genes were detected in live poultry markets in Bangladesh, these reassortants failed to supplant the dominant H5N1 lineage.

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