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1.
Transbound Emerg Dis ; 65(2): e272-e283, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29194985

RESUMO

Microarray technology can be useful for pathogen detection as it allows simultaneous interrogation of the presence or absence of a large number of genetic signatures. However, most microarray assays are labour-intensive and time-consuming to perform. This study describes the development and initial evaluation of a multiplex reverse transcription (RT)-PCR and novel accompanying automated electronic microarray assay for simultaneous detection and differentiation of seven important viruses that affect swine (foot-and-mouth disease virus [FMDV], swine vesicular disease virus [SVDV], vesicular exanthema of swine virus [VESV], African swine fever virus [ASFV], classical swine fever virus [CSFV], porcine respiratory and reproductive syndrome virus [PRRSV] and porcine circovirus type 2 [PCV2]). The novel electronic microarray assay utilizes a single, user-friendly instrument that integrates and automates capture probe printing, hybridization, washing and reporting on a disposable electronic microarray cartridge with 400 features. This assay accurately detected and identified a total of 68 isolates of the seven targeted virus species including 23 samples of FMDV, representing all seven serotypes, and 10 CSFV strains, representing all three genotypes. The assay successfully detected viruses in clinical samples from the field, experimentally infected animals (as early as 1 day post-infection (dpi) for FMDV and SVDV, 4 dpi for ASFV, 5 dpi for CSFV), as well as in biological material that were spiked with target viruses. The limit of detection was 10 copies/µl for ASFV, PCV2 and PRRSV, 100 copies/µl for SVDV, CSFV, VESV and 1,000 copies/µl for FMDV. The electronic microarray component had reduced analytical sensitivity for several of the target viruses when compared with the multiplex RT-PCR. The integration of capture probe printing allows custom onsite array printing as needed, while electrophoretically driven hybridization generates results faster than conventional microarrays that rely on passive hybridization. With further refinement, this novel, rapid, highly automated microarray technology has potential applications in multipathogen surveillance of livestock diseases.


Assuntos
Reação em Cadeia da Polimerase Multiplex/veterinária , Doenças dos Suínos/virologia , Viroses/veterinária , Vírus/classificação , Vírus da Febre Suína Africana/classificação , Vírus da Febre Suína Africana/genética , Animais , Circovirus/classificação , Circovirus/genética , Vírus da Febre Suína Clássica/classificação , Vírus da Febre Suína Clássica/genética , Enterovirus Humano B/classificação , Enterovirus Humano B/genética , Vírus da Febre Aftosa/classificação , Vírus da Febre Aftosa/genética , Limite de Detecção , Análise em Microsséries/veterinária , Vírus da Síndrome Respiratória e Reprodutiva Suína/classificação , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Suínos , Vírus do Exantema Vesicular de Suínos/classificação , Vírus do Exantema Vesicular de Suínos/genética , Viroses/virologia , Vírus/genética
2.
Virus Genes ; 53(4): 584-592, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28451944

RESUMO

Newcastle disease (ND) still remains one of the most important diseases affecting domestic poultry in Colombia. Here, for the first time, we report on the molecular characterization of 12 virulent and 12 avirulent or lentogenic avian paramyxovirus type 1 (APMV-1) strains that were isolated from commercial, backyard, and game poultry in Colombia from 2008 to 2010. The 12 virulent isolates had a fusion (F) protein cleavage site with basic amino acids at positions 113, 115, and 116 and a phenylalanine at position 117 (112RRQKR*F117), characteristic of virulent strains. The remaining 12 isolates had the F protein cleavage sites 112GKQGR*L117 or 112GRQGR*L117 typical of avirulent or lentogenic APMV-1 strains. Phylogenetic analysis of full-length F genes of all isolates was performed, and based on the recently proposed criteria for classification of APMV-1 strains, the 24 Colombian isolates were found to belong to class II viruses and clustered into four different genotypes. Ten virulent isolates clustered with genotype VII (sub-genotype VIId), seven lentogenic strains within genotype II, five lentogenic strains with genotype I (sub-genotype Ia), and two virulent isolates within genotype XII. Our data provide essential information on the genetic diversity of AMPV-1 isolates circulating in Colombia.


Assuntos
Doença de Newcastle/virologia , Vírus da Doença de Newcastle/isolamento & purificação , Doenças das Aves Domésticas/virologia , Animais , Colômbia , Genótipo , Vírus da Doença de Newcastle/classificação , Vírus da Doença de Newcastle/genética , Vírus da Doença de Newcastle/patogenicidade , Filogenia , Aves Domésticas , Sorogrupo , Proteínas Virais/genética , Proteínas Virais/metabolismo , Virulência
3.
Transbound Emerg Dis ; 64(2): 476-486, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26190467

RESUMO

Bluetongue is a non-contagious, haemorrhagic, Culicoides-borne disease of ruminants. The causative agent, bluetongue virus (BTV), is a member of the Orbivirus genus of the Reoviridae family. So far, 26 BTV serotypes have been identified worldwide. The global distribution of bluetongue has been expanding, and rapid detection of BTV, preferably in the field, is critical for timely implementation of animal movement restrictions and vector control measures. To date, many laboratory-based, molecular assays for detection of BTV have been developed. These methods require the samples to be shipped to a central laboratory with sophisticated instruments and highly skilled technicians to perform the assays, conduct analyses and interpret the results. Here, we report the development and evaluation of a rapid, portable, user-friendly, pan-BTV reverse transcription-insulated isothermal polymerase chain reaction (RT-iiPCR) assay that can potentially be used in low-resource field conditions. The total length of the assay was <60 min, and at the end of the assay, the results were automatically displayed as '+' or '-' without the need for data interpretation. The RT-iiPCR assay detected 36 BTV isolates and two in vitro transcribed RNA samples representing all 26 BTV serotypes. The assay did not cross-react with other animal viruses tested, including two closely related orbiviruses. The analytical sensitivity of the assay was as low as nine copies of in vitro transcribed double-stranded BTV RNA. Analysis of BTV-infected whole blood samples showed that the BTV RT-iiPCR assay was as sensitive as real-time RT-PCR. The assay can potentially be used for rapid screening of animals for BTV in routine diagnostics and for monitoring bluetongue outbreaks both in ruminants and in Culicoides vectors in the field and in the laboratory.


Assuntos
Vírus Bluetongue/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Animais , Vírus Bluetongue/genética , RNA Viral/genética , Ruminantes , Sensibilidade e Especificidade
4.
Transbound Emerg Dis ; 64(6): 1929-1934, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27878975

RESUMO

Microarrays can be a useful tool for pathogen detection as it allow for simultaneous interrogation of the presence of a large number of genetic sequences in a sample. However, conventional microarrays require extensive manual handling and multiple pieces of equipment for printing probes, hybridization, washing and signal detection. In this study, a reverse transcription (RT)-PCR with an accompanying novel automated microarray for simultaneous detection of eight viruses that affect cattle [vesicular stomatitis virus (VSV), bovine viral diarrhoea virus type 1 and type 2, bovine herpesvirus 1, bluetongue virus, malignant catarrhal fever virus, rinderpest virus (RPV) and parapox viruses] is described. The assay accurately identified a panel of 37 strains of the target viruses and identified a mixed infection. No non-specific reactions were observed with a panel of 23 non-target viruses associated with livestock. Vesicular stomatitis virus was detected as early as 2 days post-inoculation in oral swabs from experimentally infected animals. The limit of detection of the microarray assay was as low as 1 TCID50 /ml for RPV. The novel microarray platform automates the entire post-PCR steps of the assay and integrates electrophoretic-driven capture probe printing in a single user-friendly instrument that allows array layout and assay configuration to be user-customized on-site.


Assuntos
Doenças dos Bovinos/diagnóstico , Coinfecção/veterinária , Reação em Cadeia da Polimerase Multiplex/veterinária , Análise de Sequência com Séries de Oligonucleotídeos/veterinária , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Viroses/veterinária , Animais , Bovinos , Doenças dos Bovinos/virologia , Coinfecção/diagnóstico , Coinfecção/virologia , Reação em Cadeia da Polimerase Multiplex/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Sensibilidade e Especificidade , Viroses/diagnóstico , Viroses/virologia , Vírus/isolamento & purificação
5.
Transbound Emerg Dis ; 63(6): 590-594, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27616070

RESUMO

Soon after the emergence of 2009 pandemic H1N1, the first outbreaks in breeder turkey operations were reported that implicated human-to-turkey transmission. In the spring of 2016, the reoccurrence of 2009 pandemic H1N1 lineage viruses infecting breeder turkey flocks in Ontario and Manitoba, Canada, also implicated human-to-turkey transmission. In addition to raising concerns over biosecurity and vaccine failures, these cases once again raise the issue of whether turkeys have the potential to act as a bridge species to generate novel influenza A virus reassortants with public health implications.


Assuntos
Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Aviária/etiologia , Influenza Humana/transmissão , Animais , Canadá , Surtos de Doenças , Humanos , Vacinas contra Influenza/imunologia , Influenza Aviária/epidemiologia , Manitoba , Ontário , Vírus Reordenados , Recidiva , Perus
6.
Transbound Emerg Dis ; 63(5): e395-402, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25644051

RESUMO

Classical swine fever (CSF) is an OIE-listed disease that can have a severe impact on the swine industry. User-friendly, sensitive, rapid diagnostic tests that utilize low-cost field-deployable instruments for CSF diagnosis can be useful for disease surveillance and outbreak monitoring. In this study, we describe validation of a new probe-based insulated isothermal reverse transcriptase PCR (iiRT-PCR) assay for rapid detection of classical swine fever virus (CSFV) on a compact, user-friendly device (POCKIT(™) Nucleic Acid Analyzer) that does not need data interpretation by the user. The assay accurately detected CSFV RNA from a diverse panel of 33 CSFV strains representing all three genotypes plus an additional in vitro-transcribed RNA from cloned sequences representing a vaccine strain. No cross-reactivity was observed with a panel of 18 viruses associated with livestock including eight other pestivirus strains (bovine viral diarrhoea virus type 1 and type 2, border disease virus, HoBi atypical pestivirus), African swine fever virus, swine vesicular disease virus, swine influenza virus, porcine respiratory and reproductive syndrome virus, porcine circovirus 1, porcine circovirus 2, porcine respiratory coronavirus, vesicular exanthema of swine virus, bovine herpes virus type 1 and vesicular stomatitis virus. The iiRT-PCR assay accurately detected CSFV as early as 2 days post-inoculation in RNA extracted from serum samples of experimentally infected pigs, before appearance of clinical signs. The limit of detection (LOD95% ) calculated by probit regression analysis was 23 copies per reaction. The assay has a sample to answer turnaround time of less than an hour using extracted RNA or diluted or low volume of neat serum. The user-friendly, compact device that automatically analyses and displays results could potentially be a useful tool for surveillance and monitoring of CSF in a disease outbreak.


Assuntos
Vírus da Febre Suína Clássica/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/instrumentação , Animais , Genótipo , Sistemas Automatizados de Assistência Junto ao Leito , RNA Viral/isolamento & purificação , Sensibilidade e Especificidade , Suínos
7.
Transbound Emerg Dis ; 61(5): 397-410, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25098383

RESUMO

In January 2014, approximately 9 months following the initial detection of porcine epidemic diarrhea (PED) in the USA, the first case of PED was confirmed in a swine herd in south-western Ontario. A follow-up epidemiological investigation carried out on the initial and 10 subsequent Ontario PED cases pointed to feed as a common risk factor. As a result, several lots of feed and spray-dried porcine plasma (SDPP) used as a feed supplement were tested for the presence of PEDV genome by real-time RT-PCR assay. Several of these tested positive, supporting the notion that contaminated feed may have been responsible for the introduction of PEDV into Canada. These findings led us to conduct a bioassay experiment in which three PEDV-positive SDPP samples (from a single lot) and two PEDV-positive feed samples supplemented with this SDPP were used to orally inoculate 3-week-old piglets. Although the feed-inoculated piglets did not show any significant excretion of PEDV, the SDPP-inoculated piglets shed PEDV at a relatively high level for ≥9 days. Despite the fact that the tested PEDV genome positive feed did not result in obvious piglet infection in our bioassay experiment, contaminated feed cannot be ruled out as a likely source of this introduction in the field where many other variables may play a contributing role.


Assuntos
Ração Animal/virologia , Infecções por Coronavirus/veterinária , Diarreia/veterinária , Surtos de Doenças/veterinária , Vírus da Diarreia Epidêmica Suína , Doenças dos Suínos/etiologia , Animais , Canadá/epidemiologia , Infecções por Coronavirus/virologia , Diarreia/epidemiologia , Diarreia/virologia , Contaminação de Alimentos , Dados de Sequência Molecular , Suínos , Doenças dos Suínos/epidemiologia
8.
Avian Dis ; 58(1): 1-7, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24758106

RESUMO

In November 2010, an outbreak of avian influenza (AI) due to the H5N2 subtype virus occurred in a turkey breeder farm in northern Manitoba, Canada. The only clinical signs observed were depression, decrease in food consumption, and loss of egg production. The hemagglutinin (HA) cleavage (HA(0)) site of the isolated H5N2 virus was PQRETR/GLF, consistent with low pathogenic AI viruses. The intravenous pathogenicity index of this virus was zero. Whole-genome sequencing of two isolates that originated from two different barns was performed, and both isolates had 100% identical protein sequence in PB2, HA, NP, M1, M2, NS1, and NS2. The remaining gene segments (PB1, PA, and NA) had a single amino-acid difference when compared with each other. The nucleotide and protein sequences of eight gene segments from both isolates showed 99 or greater identity with other AI viruses that have been circulating in free-living aquatic birds in Canada and the United States within the last 10 yr. Phylogenetic analysis of the HA and neuraminidase (NA) gene segments showed that these viruses are closely related to other H5 strains that have been isolated from Manitoba and other parts of Canada. Serologic testing of archived serum samples collected from these turkeys a week before the outbreak showed no evidence of AI infection. In addition, other farms that were located within 3 km radius from the infected farm and farms that had epidemiologic connection with the farm also tested negative for the presence of H5N2 AI virus or antibody. This indicates that the virus might have been introduced to the farm from wild aquatic birds only a short time before detection. Results of this study highlight the importance of early detection and the significance of ongoing Canada-wide surveillance of AI in domestic poultry as well as in wild aquatic birds/ducks.


Assuntos
Surtos de Doenças/veterinária , Vírus da Influenza A Subtipo H5N2/genética , Vírus da Influenza A Subtipo H5N2/patogenicidade , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Perus , Animais , Embrião de Galinha , Cloaca/virologia , Feminino , Testes de Inibição da Hemaglutinação/veterinária , Testes de Hemaglutinação/veterinária , Vírus da Influenza A Subtipo H5N2/isolamento & purificação , Influenza Aviária/epidemiologia , Influenza Aviária/prevenção & controle , Masculino , Manitoba/epidemiologia , Dados de Sequência Molecular , Orofaringe/virologia , Filogenia , Reação em Cadeia da Polimerase/veterinária , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/prevenção & controle , Prevalência , Análise de Sequência de DNA/veterinária , Estudos Soroepidemiológicos , Organismos Livres de Patógenos Específicos , Proteínas Virais/genética , Proteínas Virais/metabolismo , Virulência
9.
Zoonoses Public Health ; 61(1): 4-17, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23556412

RESUMO

Pigs and humans have shared influenza A viruses (IAV) since at least 1918, and many interspecies transmission events have been documented since that time. However, despite this interplay, relatively little is known regarding IAV circulating in swine around the world compared with the avian and human knowledge base. This gap in knowledge impedes our understanding of how viruses adapted to swine or man impacts the ecology and evolution of IAV as a whole and the true impact of swine IAV on human health. The pandemic H1N1 that emerged in 2009 underscored the need for greater surveillance and sharing of data on IAV in swine. In this paper, we review the current state of IAV in swine around the world, highlight the collaboration between international organizations and a network of laboratories engaged in human and animal IAV surveillance and research, and emphasize the need to increase information in high-priority regions. The need for global integration and rapid sharing of data and resources to fight IAV in swine and other animal species is apparent, but this effort requires grassroots support from governments, practicing veterinarians and the swine industry and, ultimately, requires significant increases in funding and infrastructure.


Assuntos
Doenças Endêmicas , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A/isolamento & purificação , Influenza Humana/epidemiologia , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/epidemiologia , Animais , Pesquisa Biomédica , Humanos , Vírus da Influenza A Subtipo H1N1/fisiologia , Vírus da Influenza A/fisiologia , Influenza Humana/transmissão , Cooperação Internacional , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/transmissão , Saúde Pública , Vigilância em Saúde Pública , Suínos , Doenças dos Suínos/transmissão , Doenças dos Suínos/virologia , Zoonoses
10.
Rev Sci Tech ; 33(3): 691-709, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25812199

RESUMO

The World Organisation for Animal Health (OIE) prescribes standards for the diagnosis and control of avian influenza, as well as health measures for safe trade in birds and avian products, which are based on up-to-date scientific information and risk management principles, consistent with the role of the OIE as a reference standard-setting body for the World Trade Organization (WTO). These standards and recommendations continue to evolve, reflecting advances in technology and scientific understanding of this important zoonotic disease. The avian influenza viruses form part of the natural ecosystem by virtue of their ubiquitous presence in wild aquatic birds, a fact that human intervention cannot change. For the purposes of the Terrestrial Animal Health Code (Terrestrial Code), avian influenza is defined as an infection of poultry. However, the scope of the OIE standards and recommendations is not restricted to poultry, covering the diagnosis, early detection and management of avian influenza, including sanitary measures for trade in birds and avian products. The best way to manage avian influenza-associated risks to human and animal health is for countries to conduct surveillance using recommended methods, to report results in a consistent and transparent manner, and to applythe sanitary measures described in the Terrestrial Code. Surveillance for and timely reporting of avian influenza in accordance with OIE standards enable the distribution of relevant, up-to-date information to the global community.


Assuntos
Aves , Saúde Global , Influenza Aviária/economia , Influenza Aviária/prevenção & controle , Animais , Comércio , Notificação de Doenças , Internacionalidade
11.
Transbound Emerg Dis ; 60(2): 143-51, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22510427

RESUMO

Genes encoding a major structural glycoprotein, E2, of classical swine fever viruses (CSFV) Brescia (subgroup 1.2), Paderborn (subgroup 2.1) and Kanagawa (subgroup 3.4) were constructed by removing the transmembrane domain and adding a C-terminal 6 histidine (His) tag. All the E2 constructs were efficiently expressed in a baculovirus system as 53-kDa glycosylated proteins that were identified in Western blots by their reaction with anti-His and CSFV-specific antibodies. These proteins were used as ELISA antigens to confirm the existence of an antigenic relationship between the viruses using group-specific polyclonal antisera. Antigenic differences were identified by Western blot and ELISA reactivity of the E2 proteins with a panel of monoclonal antibodies. Specifically, one monoclonal antibody (WH303) reacted with all three proteins, two monoclonal antibodies (M1660 and M1665) reacted with only the Brescia E2 protein, and three monoclonal antibodies (M1654, M1664 and M1669) reacted equally well with only Brescia and Kanagawa E2 proteins. Therefore, antibody reactivity profiles, established using recombinant E2 proteins, could be used to quickly identify novel CSFV strains as illustrated in this report with only a limited number of monoclonal antibodies. These proteins could also have added utility in the production of monoclonal antibodies and as critical reagents in diagnostic assays.


Assuntos
Variação Antigênica/imunologia , Antígenos Virais/imunologia , Baculoviridae/metabolismo , Vírus da Febre Suína Clássica/imunologia , Proteínas do Envelope Viral/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/imunologia , Variação Antigênica/genética , Antígenos Virais/genética , Baculoviridae/genética , Western Blotting , Peste Suína Clássica/imunologia , Peste Suína Clássica/virologia , Vírus da Febre Suína Clássica/genética , Ensaio de Imunoadsorção Enzimática , Variação Genética , Dados de Sequência Molecular , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Alinhamento de Sequência , Suínos , Proteínas do Envelope Viral/genética
12.
Front Immunol ; 3: 87, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22586427

RESUMO

Most monoclonal antibodies (mAbs) generated from humans infected or vaccinated with the 2009 pandemic H1N1 (pdmH1N1) influenza virus targeted the hemagglutinin (HA) stem. These anti-HA stem mAbs mostly used IGHV1-69 and bound readily to epitopes on the conventional seasonal influenza and pdmH1N1 vaccines. The anti-HA stem mAbs neutralized pdmH1N1, seasonal influenza H1N1 and avian H5N1 influenza viruses by inhibiting HA-mediated fusion of membranes and protected against and treated heterologous lethal infections in mice with H5N1 influenza virus. This demonstrated that therapeutic mAbs could be generated a few months after the new virus emerged. Human immunization with the pdmH1N1 vaccine induced circulating antibodies that when passively transferred, protected mice from lethal, heterologous H5N1 influenza infections. We observed that the dominant heterosubtypic antibody response against the HA stem correlated with the relative absence of memory B cells against the HA head of pdmH1N1, thus enabling the rare heterosubtypic memory B cells induced by seasonal influenza and specific for conserved sites on the HA stem to compete for T-cell help. These results support the notion that broadly protective antibodies against influenza would be induced by successive vaccination with conventional influenza vaccines based on subtypes of HA in viruses not circulating in humans.

13.
Transbound Emerg Dis ; 58(5): 394-401, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21463498

RESUMO

In 2005, triple-reassortant H3N2 (trH3N2) influenza A viruses were isolated from swine and turkeys in Canada. Subsequently, these viruses were isolated from humans and mink in 2006 and 2007, respectively. Following full genome sequencing, H3N2 viruses isolated from turkeys (2005), quail (2008) and swine (2009) in Canada, were characterized as trH3N2. The 2005 turkey isolate was found to be almost identical to other viruses isolated in that year, with quail and pig isolates related very closely to the 2005 trH3N2. Minimal antigenic evolution of the swine isolates relative to the reference 2005 virus was observed. These results suggest the establishment of a stable lineage of trH3N2 in Canadian pigs, with evidence for interspecies transmission to turkeys and quails.


Assuntos
Vírus da Influenza A Subtipo H3N2/genética , Infecções por Orthomyxoviridae/veterinária , Doenças das Aves Domésticas/virologia , Codorniz , Doenças dos Suínos/virologia , Perus , Animais , Antígenos Virais/genética , Canadá/epidemiologia , Clonagem Molecular , Genoma Viral , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/virologia , Doenças das Aves Domésticas/epidemiologia , Vírus Reordenados , Suínos , Doenças dos Suínos/epidemiologia
14.
Mol Cell Probes ; 24(6): 364-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20727404

RESUMO

Worldwide efforts are ongoing to improve influenza pandemic preparedness, including from the perspective of the clinical virology laboratory. In particular, much work has been devoted to the development of diagnostic assays targeted at the Highly Pathogenic Avian Influenza (HPAI) A(H5N1); much less efforts have been devoted to the A(H2) subtype. Yet, A(H2) subtype has a proven capacity to cause pandemics and is among the subtypes prioritized for surveillance and control. Although the human A(H2N2) virus that caused the pandemic of 1957 no longer circulates, many related avian A(H2) viruses circulate in avian population and could conceivably adapt to infect humans and cause a new pandemic. In this study the design and development of an RT-PCR assay specific for A(H2) subtype is presented. It is shown that the assay is highly sensitive and specific, able to detect human and avian A(H2) viruses, and can be incorporated into a multiplex assay with another previously described assay for HPAI A(H5N1).


Assuntos
Bioensaio/métodos , Vírus da Influenza A Subtipo H2N2/genética , Virus da Influenza A Subtipo H5N1/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Animais , Sequência de Bases , Aves/virologia , Primers do DNA/metabolismo , Humanos , Vírus da Influenza A Subtipo H2N2/isolamento & purificação , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Influenza Humana/epidemiologia , Influenza Humana/virologia , Dados de Sequência Molecular , Pandemias , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Alinhamento de Sequência , Análise de Sequência de DNA , Especificidade da Espécie , Sus scrofa/virologia
15.
Avian Dis ; 54(1 Suppl): 213-9, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20521634

RESUMO

In September 2007, an H7N3 highly pathogenic avian influenza outbreak (HPAI) occurred on a multiple-age broiler breeder operation near Regina Beach, Saskatchewan, Canada. Mortality was initially observed in a barn that housed 24-wk-old roosters, with later involvement of 32-wk-old breeders. All birds on the affected premises were destroyed, and surveillance of surrounding farms demonstrated no further spread. The use of water from a dugout pond during periods of high demand, and the proximity of the farm to Last Mountain Lake, the northern end of which is a bird sanctuary, implicated wild aquatic birds as a possible source of the virus. Of particular note, the H7-specific real-time reverse transcription polymerase chain reaction assay that was in use at the time did not detect the virus associated with this outbreak. A Canadian national influenza A virus survey of wild aquatic birds detected no H7 subtype viruses in 2005 and 2006; however, H7 subtype viruses were detected in the fall of 2007. Phylogenetic analysis of a number of these H7 isolates demonstrated an evolutionary relationship with each other, as well as with the H7N3 HPAI virus that was isolated from the Saskatchewan broiler breeder farm.


Assuntos
Galinhas , Surtos de Doenças/veterinária , Vírus da Influenza A/classificação , Vírus da Influenza A/patogenicidade , Influenza Aviária/epidemiologia , Animais , Canadá/epidemiologia , Vírus da Influenza A/genética , Influenza Aviária/virologia , Filogenia
16.
Avian Dis ; 54(1 Suppl): 440-5, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20521675

RESUMO

A multi-agency, Canada-wide survey of influenza A viruses circulating in wild birds, coordinated by the Canadian Cooperative Wildlife Health Centre, was begun in the summer of 2005. Cloacal swab specimens collected from young-of-year ducks were screened for the presence of influenza A nucleic acids by quantitative, real-time reverse transcription-polymerase chain reaction (RRT-PCR). Specimens that produced positive results underwent further testing for H5 and H7 gene sequences and virus isolation. In addition to live bird sampling, dead bird surveillance based on RRT-PCR was also carried out in 2006 and 2007. The prevalence of influenza A viruses varied depending on species, region of the country, and the year of sampling, but generally ranged from 20% to 50%. All HA subtypes, with the exception of H14 and H15, and all NA subtypes were identified. The three most common HA subtypes were H3, H4, and H5, while N2, N6, and N8 were the three most common NA subtypes. H4N6, H3N2, and H3N8 were the three most common HA-NA combinations. The prevalence of H5 and H7 subtype viruses appears to have a cyclical nature.


Assuntos
Aves , Vírus da Influenza A/classificação , Influenza Aviária/virologia , Animais , Animais Selvagens , Canadá/epidemiologia , Surtos de Doenças/veterinária , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/epidemiologia , Vigilância da População , Fatores de Tempo
17.
Avian Dis ; 54(1 Suppl): 548-54, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20521692

RESUMO

Highly pathogenic avian influenza (HPAI) H5N1 virus infections have caused unprecedented morbidity and mortality in different species of domestic and wild birds in Asia, Europe, and Africa. In our previous study, we demonstrated the susceptibility and potential epidemiologic importance of H5N1 HPAI virus infections in Canada geese. In this study, we investigated the potential of preexposure with North American lineage H3N8, H4N6, and H5N2 low pathogenicity avian influenza (LPAI) viruses to cross-protect Canada geese against a lethal H5N1 HPAI virus challenge. Based on our results, birds that were primed and boosted with an H5N2 LPAI virus survived a lethal H5N1 challenge. In contrast, only two of five birds from the H3N8 group and none of the birds preexposed to H4N6 survived a lethal H5N1 challenge. In vitro cell proliferation assays demonstrated that peripheral blood mononuclear cells collected from each group were no better stimulated by homologous vs. heterologous antigens.


Assuntos
Anseriformes , Vírus da Influenza A/classificação , Influenza Aviária/imunologia , Animais , Proliferação de Células , Imuno-Histoquímica , Vírus da Influenza A/imunologia , Influenza Aviária/epidemiologia , Influenza Aviária/patologia , Influenza Aviária/virologia , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/virologia , Pulmão/patologia , América do Norte/epidemiologia , Eliminação de Partículas Virais
18.
Transbound Emerg Dis ; 57(4): 262-70, 2010 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-20545910

RESUMO

Classical swine fever (CSF) is considered to be endemic in Peru with outbreaks reported to the World Organization for Animal Health as recently as 2008 and 2009. Nevertheless, little is known regarding the genetic subgroup(s) of CSF virus that are circulating in Peru or their relationship to recent CSF viruses that have been isolated from neighbouring South American countries or other parts of the world. In this study, we molecularly characterize CSF viruses that were isolated from domestic pigs from different regions of Peru from the middle of 2007 to early 2008. All virus isolates were found to belong to genetic subgroup 1.1, consistent with the subgroup of viruses that have been identified from other South American countries. Although the Peruvian isolates are most closely related to viruses from Colombia and Brazil, they form a monophyletic clade, which suggests they have a distinct evolutionary history.


Assuntos
Vírus da Febre Suína Clássica/genética , Peste Suína Clássica/virologia , Filogenia , Animais , Peste Suína Clássica/epidemiologia , Vírus da Febre Suína Clássica/classificação , Peru/epidemiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Suínos
19.
Rev Sci Tech ; 28(1): 349-58, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19618638

RESUMO

Reports of sporadic avian influenza outbreaks involving domestic poultry date back to the 1960s. With the exception of A/turkey/Ontario/7732/1966 (H5N9), which was isolated from a turkey breeding establishment, all viruses characterised prior to 2004 fit the criteria of low pathogenic avian influenza (LPAI). Only in retrospect was A/turkey/Ontario/7732/1966 shown to meet the criteria of a highly pathogenic avian influenza (HPAI). In 2004, Canada reported its first case of HPAI to the World Organisation for Animal Health (OIE). The outbreak, which began in a broiler breeder farm in the Fraser Valley of British Columbia, involved an H7N3 LPAI virus which underwent a sudden virulence shift to HPAI. More than 17 million birds were culled and CAN$380 million in gross economic costs incurred before the outbreak was eventually brought under control. In its aftermath a number of changes were implemented to mitigate the impact of any future HPAI outbreaks. These changes involved various aspects of avian influenza detection and control, including self-quarantine, biosecurity, surveillance, and laboratory testing. In 2005, a national surveillance programme for influenza A viruses in wild birds was initiated. Results of this survey provided evidence for wild birds as the likely source of an H5N2 LPAI outbreak that occurred in domestic ducks in the Fraser Valley in the autumn of 2005. Wild birds were once again implicated in an H7N3 HPAI outbreak involving a broiler breeder operation in Saskatchewan in 2007. Fortunately, both of these outbreaks were limited in extent, a consequence of some of the changes implemented in response to the 2004 British Columbia outbreak.


Assuntos
Surtos de Doenças/veterinária , Vírus da Influenza A Subtipo H5N2/patogenicidade , Vírus da Influenza A/patogenicidade , Influenza Aviária/epidemiologia , Animais , Aves , Canadá/epidemiologia , Surtos de Doenças/economia , Vírus da Influenza A/classificação , Influenza Aviária/economia , Influenza Aviária/virologia , Aves Domésticas , Vigilância de Evento Sentinela/veterinária
20.
Vet Pathol ; 46(5): 966-70, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19429986

RESUMO

Susceptibility of Canada geese (Branta canadensis) to highly pathogenic avian influenza (HPAI) virus (H5N1) infection was studied by inoculating 10 naïve (antibody-negative) animals (5 adults and 5 juveniles) with A/chicken/Vietnam/14/05 (H5N1) virus. In the adults, 1 of 5 became infected, and 4 of 5 remained normal; in the juvenile group, 5 of 5 became infected. The pathology observed in the affected animals was similar to that reported in natural occurrences. Peripheral and parasympathetic nervous systems were examined and found infected, as well as cerebrospinal fluid-contacting neurons. In some locations with significant virus infection in cells, the expected inflammatory reaction was absent or very mild. Immunohistochemistry was used to locate influenza A virus nucleoprotein in brain, spinal cord, respiratory and digestive systems, pancreas, heart, and peripheral and parasympathetic nervous systems. Further studies are needed to explain age-related differences in susceptibility.


Assuntos
Doenças das Aves/virologia , Gansos , Virus da Influenza A Subtipo H5N1/imunologia , Influenza Aviária/imunologia , Fatores Etários , Animais , Doenças das Aves/imunologia , Sistema Nervoso Central/virologia , Histocitoquímica/veterinária , Influenza Aviária/virologia , Pulmão/virologia , Pâncreas/virologia , Projetos Piloto
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