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1.
Pesqui. vet. bras ; 42: e07037, 2022. ilus, mapas, tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1437016

Resumo

The effectiveness of vectored recombinant vaccines to control infectious laryngotracheitis (ILT) in chickens from a region (State of Minas Gerais, Brazil) with ~10 million layers was evaluated under field conditions from 2014-2018. During this period, only recombinant turkey herpesvirus (rHVT) or fowl poxvirus (rFPV) vaccines that express antigens of infectious laryngotracheitis virus (Gallid herpesvirus-1; GaHV-1) were used. Layer chickens (n=1,283), from eight different egg-producing companies, were individually sampled and examined (active surveillance), and in instances when government poultry health veterinarians were notified due to respiratory disease (passive surveillance). Clinical, macroscopic, and histopathology examinations were performed to diagnose ILT as well as molecular techniques for the detection and characterization of the GaHV-1 DNA from the trachea and trigeminal ganglia (TG). The layer hens sampled and examined belonged to flocks and farms that used different vaccination protocols (non-vaccinated, single dose vaccination, and prime/ boost vaccination). This is the first long-term field study of the effectiveness of ILT vectored vaccines in a high-density multiple age layer hen region. Using various diagnostic methods, the occurrence of GaHV-1 infection and ILT clinical disease in layer hens vaccinated with vectored recombinant vaccines in one quarantined region of Brazil were investigated. The number of ILTV positive chickens by PCR and ILT clinical disease cases was lower in farms when all chickens were vaccinated with at least one vaccine. However, the difference in the detection rates of GaHV-1 infection was significant only when compared farms with prime/ boost and farms using single dose of HTV-LT.


A efetividade das vacinas recombinantes vetorizadas para o controle da laringotraqueíte infecciosa (LTI) nas aves de uma região (Minas Gerais, Brasil) com aproximadamente 10 milhões de poedeiras foi avaliada em condições de campo, no período de 2014 a 2018. Durante este período, somente as vacinas recombinantes "turkey herpesvirus" (rHVT) ou "fowl poxvirus" (rFPV), que expressam antígenos do vírus da laringotraqueíte (Gallid herpesvirus-1; GaHV-1) foram utilizadas. Galinhas poedeiras (n=1.283), de oito diferentes granjas produtoras de ovos, foram individualmente amostradas e examinadas por monitoramento ativo e, na ocorrência de notificação de doença respiratória aos veterinários do serviço oficial, por monitoramento passivo. Exames clínicos, macroscópicos e histopatológicos foram realizados para o diagnóstico de LTI, bem como técnicas moleculares para a detecção e caracterização do DNA de GaHV-1 da traqueia e gânglio trigêmeo. As galinhas poedeiras pertenciam a lotes e granjas que usavam diferentes protocolos de vacinação (não vacinadas, uma dose ou tipo de vacina e duas doses ou tipos de vacina). Este é o primeiro longo estudo a campo sobre a efetividade das vacinas vetorizadas em uma região com população elevada de poedeiras de múltiplas idades. Utilizando vários métodos de diagnóstico, a ocorrência da infecção por GaHV-1 e a LTI clínica em poedeiras de uma região interditada do Brasil foi investigada. O número de galinhas positivas para o vírus GaHV-1 e para casos clínicos de LTI nas granjas foi menor quando todas as aves estavam vacinadas com, pelo menos, um tipo ou dose de vacina. Entretanto, a diferença na taxa de detecção da infecção por GaHV-1 foi significativa somente quando a comparação foi realizada entre granjas com aves vacinadas com duas doses e aves de granjas vacinadas com uma única dose de HVT-LT.


Assuntos
Animais , Vacinas Virais/análise , Galinhas/virologia , Análise de Sequência/veterinária , Herpesvirus Galináceo 1/isolamento & purificação , Reação em Cadeia da Polimerase/veterinária
2.
Braz. J. Vet. Pathol. ; 14(2): 88-98, jul. 2021. tab, ilus, graf
Artigo em Inglês | VETINDEX | ID: vti-31226

Resumo

Infectious laryngotracheitis (ILT) is a severe respiratory disease, which causes high morbidity and mortality in affected birds. In our study, ILT were reported in 42 farms from nine governates over two years (2018–2020) that showed clinical signs of ILT including dyspnea, blood expectoration of, excessive lacrimation, rattling, conjunctivitis. The disease affected different chicken breeds and age groups despite vaccination with licensed and commonly used vaccines. Samples of larynx, trachea, lungs and air sacs were examined and collected for histopathological, ultrastructural, immunohistochemical examination and molecular detection. Gross examination of laryngeal and tracheal lumen revealed different types of exudate varied from catarrhal to fibrinonecotric, also pneumonia and airsacculitis were detected. Histopathological examination showed different alternation in larynx, trachea, lung and air sac as characteristic syncytial cells containing intranuclear inclusion body hanged in fibrinoheterphilic exudate that precent in laryngeal, tracheal, bronchial and parabronchial lumen and air sacs. Tracheal lesion scoring system was used to categorize the severity of lesion in different governates. Tracheal lesion score showed that 6.02%, 26.5%, 43.3% of the birds exhibited mild, moderate, and severe changes, respectively, while 24.18% of the birds exhibited very severe changes. Furthermore, severe cases were related to the Qalyubia , Fayoum then Sharkia Governorate. Moreover, immunohistochemistry was used to detect viral particles in syncytial cells, inflammatory cells beside epithelium of trachea and lung. Transmission electron microscopy enabled the detection of virus particles and demonstrated that heterophils could be infected. PCR targeting a region in the thymidine kinase gene and glycoprotein gJ gene confirmed the presence of infectious laryngotracheitis ILT virus-specific DNA. In conclusion, anatomopathological, immunohistochemical, molecular and ultrastructural findings showed increased of ILTV severity in Egypt. Larynx, trachea, lungs and air sac should be collected and examined that aid in diagnosis. Importance of good biosecurity level to be considered.(AU)


Assuntos
Animais , Aves Domésticas/anatomia & histologia , Aves Domésticas/imunologia , Aves Domésticas/microbiologia , Herpesvirus Galináceo 1/classificação , Herpesvirus Galináceo 1/patogenicidade , Imuno-Histoquímica/veterinária , Reação em Cadeia da Polimerase , Microscopia Eletrônica
3.
Braz. j. vet. pathol ; 14(2): 88-98, jul. 2021. tab, ilus, graf
Artigo em Inglês | VETINDEX | ID: biblio-1469792

Resumo

Infectious laryngotracheitis (ILT) is a severe respiratory disease, which causes high morbidity and mortality in affected birds. In our study, ILT were reported in 42 farms from nine governates over two years (2018–2020) that showed clinical signs of ILT including dyspnea, blood expectoration of, excessive lacrimation, rattling, conjunctivitis. The disease affected different chicken breeds and age groups despite vaccination with licensed and commonly used vaccines. Samples of larynx, trachea, lungs and air sacs were examined and collected for histopathological, ultrastructural, immunohistochemical examination and molecular detection. Gross examination of laryngeal and tracheal lumen revealed different types of exudate varied from catarrhal to fibrinonecotric, also pneumonia and airsacculitis were detected. Histopathological examination showed different alternation in larynx, trachea, lung and air sac as characteristic syncytial cells containing intranuclear inclusion body hanged in fibrinoheterphilic exudate that precent in laryngeal, tracheal, bronchial and parabronchial lumen and air sacs. Tracheal lesion scoring system was used to categorize the severity of lesion in different governates. Tracheal lesion score showed that 6.02%, 26.5%, 43.3% of the birds exhibited mild, moderate, and severe changes, respectively, while 24.18% of the birds exhibited very severe changes. Furthermore, severe cases were related to the Qalyubia , Fayoum then Sharkia Governorate. Moreover, immunohistochemistry was used to detect viral particles in syncytial cells, inflammatory cells beside epithelium of trachea and lung. Transmission electron microscopy enabled the detection of virus particles and demonstrated that heterophils could be infected. PCR targeting a region in the thymidine kinase gene and glycoprotein gJ gene confirmed the presence of infectious laryngotracheitis ILT virus-specific DNA. In conclusion, anatomopathological, immunohistochemical, molecular and ultrastructural findings showed increased of ILTV severity in Egypt. Larynx, trachea, lungs and air sac should be collected and examined that aid in diagnosis. Importance of good biosecurity level to be considered.


Assuntos
Animais , Aves Domésticas/anatomia & histologia , Aves Domésticas/imunologia , Aves Domésticas/microbiologia , Herpesvirus Galináceo 1/classificação , Herpesvirus Galináceo 1/patogenicidade , Imuno-Histoquímica/veterinária , Microscopia Eletrônica , Reação em Cadeia da Polimerase
4.
Rev. bras. ciênc. avic ; 18(4): 551-562, Out-Dez. 2016.
Artigo em Inglês | VETINDEX | ID: biblio-1490302

Resumo

Avian Infectious laryngotracheitis (AILT) is a respiratory tract disease of great importance because it causes significant economic losses in the poultry industry around the world. It is caused by a Gallid herpesvirus type 1, a member of the genus Iltovirus. The target system for Avian Infectious Laryngotracheitis virus (AILTV) infections is the respiratory system, and the main organ in which the virus remains latent is the trigeminal ganglia. However, the virus has demonstrated tropism for other organs besides the respiratory tract. The main transmission routes are ocular and respiratory. Infected birds with clinical symptoms are main sources of transmission, but birds with latent infections, litter, and contaminated fomites may also transmit the virus. Clinical signs usually appear 6-12 days after natural exposure and may be moderate or severe. The causative agent of this disease can be propagated in chorioallantoic membrane (CAM) of developing chicken embryos and replicate in mature chicken kidney cells, as well as in a variety of epithelial chick embryo cells, such as kidneys, liver and lungs. There are several procedures for the diagnosis of ILT such as the observation of clinical signs, the detection of gross and histopathological lesions, and the use of molecular techniques, including RFLP, polymerase chain reaction (PCR), real-time PCR, and loop-mediated isothermal amplification. Vaccination with different types of vaccine provides a good expectation on disease control, such as vaccines produced in chicken-embryo-origin (CEO), tissue-culture-origin (TCO), and recombinant vaccines. However, in endemic areas, biosecurity measures and best management practices are important for the control of the disease. It is distributed worldwide and, in South America, it has been reported in Brazil, Peru, Ecuador, Bolivia, and Argentina causing great economic losses.


Assuntos
Animais , Doenças Endêmicas/veterinária , Epidemiologia , Galinhas/fisiologia , Herpesvirus Galináceo 1/fisiologia , Herpesvirus Galináceo 1/patogenicidade , Iltovirus/patogenicidade , Infecções por Herpesviridae/veterinária , Sistema Respiratório/patologia , Controle de Doenças Transmissíveis , Diagnóstico , Transmissão de Doença Infecciosa/veterinária , Vacinas contra Herpesvirus/uso terapêutico
5.
R. bras. Ci. avíc. ; 18(4): 551-562, Out-Dez. 2016.
Artigo em Inglês | VETINDEX | ID: vti-683973

Resumo

Avian Infectious laryngotracheitis (AILT) is a respiratory tract disease of great importance because it causes significant economic losses in the poultry industry around the world. It is caused by a Gallid herpesvirus type 1, a member of the genus Iltovirus. The target system for Avian Infectious Laryngotracheitis virus (AILTV) infections is the respiratory system, and the main organ in which the virus remains latent is the trigeminal ganglia. However, the virus has demonstrated tropism for other organs besides the respiratory tract. The main transmission routes are ocular and respiratory. Infected birds with clinical symptoms are main sources of transmission, but birds with latent infections, litter, and contaminated fomites may also transmit the virus. Clinical signs usually appear 6-12 days after natural exposure and may be moderate or severe. The causative agent of this disease can be propagated in chorioallantoic membrane (CAM) of developing chicken embryos and replicate in mature chicken kidney cells, as well as in a variety of epithelial chick embryo cells, such as kidneys, liver and lungs. There are several procedures for the diagnosis of ILT such as the observation of clinical signs, the detection of gross and histopathological lesions, and the use of molecular techniques, including RFLP, polymerase chain reaction (PCR), real-time PCR, and loop-mediated isothermal amplification. Vaccination with different types of vaccine provides a good expectation on disease control, such as vaccines produced in chicken-embryo-origin (CEO), tissue-culture-origin (TCO), and recombinant vaccines. However, in endemic areas, biosecurity measures and best management practices are important for the control of the disease. It is distributed worldwide and, in South America, it has been reported in Brazil, Peru, Ecuador, Bolivia, and Argentina causing great economic losses.(AU)


Assuntos
Animais , Epidemiologia , Herpesvirus Galináceo 1/fisiologia , Herpesvirus Galináceo 1/patogenicidade , Sistema Respiratório/patologia , Infecções por Herpesviridae/veterinária , Iltovirus/patogenicidade , Galinhas/fisiologia , Doenças Endêmicas/veterinária , /prevenção & controle , /estatística & dados numéricos , Vacinas contra Herpesvirus/uso terapêutico , Transmissão de Doença Infecciosa/veterinária , Controle de Doenças Transmissíveis , Diagnóstico
6.
Tese em Português | VETTESES | ID: vtt-221984

Resumo

A sanidade avícola é necessária para garantir a posição de destaque mundial da avicultura brasileira. O objetivo deste trabalho foi realizar a vigilância epidemiológica do vírus da IA (VIA) e do vírus da DNC (VDNC) em 2017 e 2018, além de avaliar a circulação de estirpes do vírus de laringotraqueíte infecciosa das galinhas (VLTI) nas granjas de postura comercial em duas regiões quarentemadas (Bastos e Guatapará) entre 2010 e 2018. Diferentes programas vacinais contra a LTI foram implementados na região, com a substituição de vacinas vivas atenuadas por recombinantes em 2012 (Bastos) e 2013 (Guatapará). Para a vigilância de VIA e VDNC foram coletados pools de suabes (traqueais e cloacais, n=220) de aves de subsistências localizadas no entorno de propriedades avícolas de reprodutoras. Essas amostras foram testadas pela reação de transcrição reversa-PCR em tempo real (RRT-PCR). O estudo longitudinal de VLTI coletou amostras de pools de suabes orofaríngeos de aves localizadas em Bastos (n=364) e Guatapará (n=214) para a detecção de VLTI por PCR. O sequenciamento de DNA dos genes ICP4, TK e genomas completos das amostras positivas foram realizados usando sequenciamento Sanger e sequenciamento de última geração (NGS). As bibliotecas de DNA foram preparadas com o kit Nextera DNA Flex Library Prep e sequenciadas com o sequenciador MiSeq. Análise filogenética e as identidades genéticas foram inferidas com as sequências obtidas. Nosso estudo não detectou VIA e do VDNC em nenhuma das amostras no período avaliado. O VLTI foi detectado em 11,85% e 12,6% das amostras testadas de Bastos em 2013 e 2018. A região de Guatapará apresentou a maior taxa de detecção (60,5%) em 2010. A taxa de detecção de amostras testadas da região de Guatapará variou de 12,2% e 21,7% após 2013. Análise filogenética do gene ICP4 agrupou as sequências das amostras de Bastos com vacinas de CEO e outras sequências de Bastos detectadas em anos anteriores, com 99% da identidade genética entre estas sequências. As análises filogenéticas dos genes ICP4, TK e do genoma completo agruparam as amostras de Guatapará separadamente das amostras vacinais. A sequência completa do genoma de uma amostra obtida de aves sintomáticas sem vacinação na região de Guatapará em 2010 (IB8098) teve 152.985 nucleotídeos, com 4755 leituras e 98,2% de cobertura. A análise filogenética agrupou a amostra IB8098 com outras estirpes virulentas, como da Rússia (MF405079). As identidades genéticas apresentaram 99,9%, quando comparadas à estirpe russa e 99,6% em relação às vacinais (CEO e TCO). Nosso estudo mostrou o VLTI ainda está presente nas regiões de Bastos e Guatapará, apesar das medidas de controle e vacinação vigentes. Os programas de vacinação nas regiões quarentenadas diminuíram a circulação do vírus com um leve aumento da detecção do VLTI com a utilização apenas das vacinas recombinantes. Esse é o primeiro relato da obtenção do genoma completo de VLTI no Brasil e sua caracterização genômica desde o início da circulação do vírus na região há pelo menos dez anos. O monitoramento contínuo da área é essencial para auxiliar as ações da defesa agropecuária, avaliar as medidas de vacinação implementadas contribuindo para a melhoria da sanidade avícola.


Poultry health is important to ensure the world's leading position in Brazilian poultry production. The present study performed the epidemiological surveillance of avian influenza virus (AIV) and Newcastle disease virus (NDV) in 2017 and 2018; the circulation of virulent avian infection laryngotracheitis virus (ILTV) strains was also evaluated in commercial layer farms from two quarantined regions (Bastos and Guatapara) between 2010 and 2018. Different vaccine programs against ILT were established in the area, and a replacement of live vaccines by recombinant vaccines was done in 2012 (Bastos) and 2013 (Guatapara). For the AIV and NDV surveillance, swab pool samples (trachea and cloacal, n=220) were collected from backyard birds located closed to breeder farms. Real-time reverse-transcription polymerase chain reaction (RRT-PCR) tested these samples. The longitudinal study collected oropharyngeal swab pool samples from commercial layer chickens located in Bastos (n=364) and Guatapara (n=214) for virus ILTV detection by PCR. DNA sequencing from the ICP4, TK genes and complete genomes was performed in positive samples using Sanger sequencing and next-generation sequencing (NGS). DNA libraries were prepared with the Nextera DNA Flex Library Prep kit, sequenced with the MiSeq sequencer for NGS. Phylogenetic analysis and genetic identities were inferred using the obtained sequences. AIV and NDV were not detected in any sample during the study. ILTV was detected in 11.85% and 12.6% of tested samples from Bastos in 2013 and 2018. Guatapara region had the highest detection rate (60.5%) in 2010. The detection rate from tested samples of the Guatapara region ranged from 12.2% and 21.7% after 2013. Phylogenetic analysis based on ICP4 gene grouped sequences from Bastos samples with CEO vaccines and other sequences detected previously in Bastos, with 99% of nucleotide identity among them. Phylogenetic analysis based on ICP4, TK, and complete genomes grouped sequences from Guatapara separately from vaccine strains. The complete genome sequence of a sample (IB8098), collected from layer chickens displaying clinical signs without vaccination in the Guatapara region in 2010, had 152,985 nucleotides, with 4,755 reads and 98,2% coverage. The phylogenetic analysis grouped the IB8098 sample with other virulent ILTV strains, such as from Russia (MF405079). Nucleotide identities were 99.9% compared to the Russian, and 99.6% to vaccine strains (CEO and TCO). Our study showed the ILTV is still present in the Bastos and Guatapara regions, despite the control and vaccination measures. The vaccination programs in the quarantine regions decreased the virus circulation, slightly increasing when only recombinant vaccines were applied. That is the first report of complete genome ILTV sequences in Brazil and its genomic characterization, after its circulation in the region for at least ten years. Continuous monitoring in poultry flocks is essential to help the poultry health measures, evaluate the vaccination programs placed in the area contributing to the Brazilian poultry health plans improvement.

7.
Rev. bras. ciênc. avic ; 17(1): 117-121, jan.-mar. 2015. ilus, tab
Artigo em Inglês | VETINDEX | ID: biblio-1490125

Resumo

Infectious laryngotracheitis is a very important respiratory disease because it causes significant economic losses in the poultry industry. The target of ILTV infections is the respiratory system, and the main organ in which the virus remains latent is the trigeminal ganglia. However, the virus has demonstrated tropism for other organs as well. The present study was conducted to determine the presence of Infectious Laryngotracheitis Virus (ILTV) in the state of São Paulo. Samples submitted to LABOR- USP during the last four years (2009-2013) analyzed by a nested/PCR technique. Out of the 682 samples from layers tested for LTIV, 12.46 % were positive, and derived from in both traditional (trachea and trigeminal ganglion) and untraditional (cecal tonsils, digestive tract and kidneys) organs utilized for ILTV diagnosis. The present work showed that ILTV is circulating in commercial layer flocks in São Paulo State, and that the LTIV is present in other organs in addition to the respiratory tract and trigeminal ganglion; however, it was not determined if the circulating virus is a vaccinal or field strain.


Assuntos
Feminino , Animais , Herpesvirus Galináceo 1/classificação , Herpesvirus Galináceo 1/crescimento & desenvolvimento
8.
R. bras. Ci. avíc. ; 17(1): 117-121, jan.-mar. 2015. ilus, tab
Artigo em Inglês | VETINDEX | ID: vti-39536

Resumo

Infectious laryngotracheitis is a very important respiratory disease because it causes significant economic losses in the poultry industry. The target of ILTV infections is the respiratory system, and the main organ in which the virus remains latent is the trigeminal ganglia. However, the virus has demonstrated tropism for other organs as well. The present study was conducted to determine the presence of Infectious Laryngotracheitis Virus (ILTV) in the state of São Paulo. Samples submitted to LABOR- USP during the last four years (2009-2013) analyzed by a nested/PCR technique. Out of the 682 samples from layers tested for LTIV, 12.46 % were positive, and derived from in both traditional (trachea and trigeminal ganglion) and untraditional (cecal tonsils, digestive tract and kidneys) organs utilized for ILTV diagnosis. The present work showed that ILTV is circulating in commercial layer flocks in São Paulo State, and that the LTIV is present in other organs in addition to the respiratory tract and trigeminal ganglion; however, it was not determined if the circulating virus is a vaccinal or field strain.(AU)


Assuntos
Animais , Feminino , Herpesvirus Galináceo 1/classificação , Herpesvirus Galináceo 1/crescimento & desenvolvimento
9.
Cad. técn. Vet. Zoot. ; (76): 79-95, mar. 2015. ilus
Artigo em Português | VETINDEX | ID: vti-886

Resumo

A laringotraqueíte infecciosa (LTI)é uma infecção virale de distribuição cosmopolita que acomete especialmente o trato respiratório superior e a conjuntiva das aves comerciais 21,33.O vírus da laringotraqueíte pertence ao gênero Iltovirus,família Herpesviridae e subfamília Herpesvirinae. O vírus é taxonomicamente identificado como Gallid herpesvírus 1 (GaHV-1).


Assuntos
Animais , Herpesvirus Galináceo 1/fisiologia , Herpesvirus Galináceo 1/patogenicidade , Diagnóstico Diferencial , Doenças Respiratórias/diagnóstico , Doenças Respiratórias/terapia , Galinhas/fisiologia , Patologia , Aves Domésticas/fisiologia , Aves Domésticas/virologia , Criação de Animais Domésticos
10.
Cad. téc. vet. zootec ; (76): 79-95, mar. 2015. ilus
Artigo em Português | VETINDEX | ID: biblio-1471488

Resumo

A laringotraqueíte infecciosa (LTI)é uma infecção virale de distribuição cosmopolita que acomete especialmente o trato respiratório superior e a conjuntiva das aves comerciais 21,33.O vírus da laringotraqueíte pertence ao gênero Iltovirus,família Herpesviridae e subfamília Herpesvirinae. O vírus é taxonomicamente identificado como Gallid herpesvírus 1 (GaHV-1).


Assuntos
Animais , Diagnóstico Diferencial , Doenças Respiratórias/diagnóstico , Doenças Respiratórias/terapia , Galinhas/fisiologia , Herpesvirus Galináceo 1/fisiologia , Herpesvirus Galináceo 1/patogenicidade , Aves Domésticas/fisiologia , Aves Domésticas/virologia , Criação de Animais Domésticos , Patologia
11.
Artigo em Inglês | VETINDEX | ID: vti-16123

Resumo

Seventy-eight chickens from a very high poultry density (approximately eight million) region and twelve backyard chickens from neighboring areas were analyzed by histopathology and additional techniques for the presence of the infectious laryngotracheitis virus. The virus distribution was determined in different tissues using immunohistochemistry (IHC) and polymerase chain reaction (PCR). The disease was histopathologically diagnosed in 41.0% (32/78) of the commercial layers. Lesions were mainly characterized by syncytial cells with eosinophilic intranuclear inclusion body formed from the hyperplastic epithelium of the upper respiratory tract, primary and secondary bronchi, and conjunctiva. IHC showed 70% (21/30) positive signal in the larynx/trachea and, 53.8% (14/26) in the lungs, either in epithelial cells or syncytia. In the turbinates and paranasal sinuses, 29.6% (8/27) of samples showed positive signal. PCR detected the following gallid herpesvirus 1-positive percentages: conjunctiva 63.2% (31/49), lungs 57.6% (30/52), turbinates and paranasal sinuses 56% (28/50), and larynx/trachea 50% (39/78). IHC showed to be a useful additional tool for definitive ILT diagnosis, especially during the subacute phase of the disease when syncytial cells with intranuclear inclusion bodies are no longer observed. PCR using specific primers from ICP4 gene, generating a product of 237 base pairs, was sensitive for ILT diagnosis, and very useful for rapid detection of GaHV-1 in chickens. Fixed tissues allowing histopatological examination and detection of GaHV-1 by PCR, are a good option in areas where farms are located several hundred kilometers away from a diagnostic center, reducing problems with conservation of fresh samples and the risk of virus spread.

12.
Artigo em Inglês | VETINDEX | ID: vti-15943

Resumo

Seventy-eight chickens from a very high poultry density (approximately eight million) region and twelve backyard chickens from neighboring areas were analyzed by histopathology and additional techniques for the presence of the infectious laryngotracheitis virus. The virus distribution was determined in different tissues using immunohistochemistry (IHC) and polymerase chain reaction (PCR). The disease was histopathologically diagnosed in 41.0% (32/78) of the commercial layers. Lesions were mainly characterized by syncytial cells with eosinophilic intranuclear inclusion body formed from the hyperplastic epithelium of the upper respiratory tract, primary and secondary bronchi, and conjunctiva. IHC showed 70% (21/30) positive signal in the larynx/trachea and, 53.8% (14/26) in the lungs, either in epithelial cells or syncytia. In the turbinates and paranasal sinuses, 29.6% (8/27) of samples showed positive signal. PCR detected the following gallid herpesvirus 1-positive percentages: conjunctiva 63.2% (31/49), lungs 57.6% (30/52), turbinates and paranasal sinuses 56% (28/50), and larynx/trachea 50% (39/78). IHC showed to be a useful additional tool for definitive ILT diagnosis, especially during the subacute phase of the disease when syncytial cells with intranuclear inclusion bodies are no longer observed. PCR using specific primers from ICP4 gene, generating a product of 237 base pairs, was sensitive for ILT diagnosis, and very useful for rapid detection of GaHV-1 in chickens. Fixed tissues allowing histopatological examination and detection of GaHV-1 by PCR, are a good option in areas where farms are located several hundred kilometers away from a diagnostic center, reducing problems with conservation of fresh samples and the risk of virus spread.

13.
Artigo em Inglês | VETINDEX | ID: vti-15723

Resumo

Seventy-eight chickens from a very high poultry density (approximately eight million) region and twelve backyard chickens from neighboring areas were analyzed by histopathology and additional techniques for the presence of the infectious laryngotracheitis virus. The virus distribution was determined in different tissues using immunohistochemistry (IHC) and polymerase chain reaction (PCR). The disease was histopathologically diagnosed in 41.0% (32/78) of the commercial layers. Lesions were mainly characterized by syncytial cells with eosinophilic intranuclear inclusion body formed from the hyperplastic epithelium of the upper respiratory tract, primary and secondary bronchi, and conjunctiva. IHC showed 70% (21/30) positive signal in the larynx/trachea and, 53.8% (14/26) in the lungs, either in epithelial cells or syncytia. In the turbinates and paranasal sinuses, 29.6% (8/27) of samples showed positive signal. PCR detected the following gallid herpesvirus 1-positive percentages: conjunctiva 63.2% (31/49), lungs 57.6% (30/52), turbinates and paranasal sinuses 56% (28/50), and larynx/trachea 50% (39/78). IHC showed to be a useful additional tool for definitive ILT diagnosis, especially during the subacute phase of the disease when syncytial cells with intranuclear inclusion bodies are no longer observed. PCR using specific primers from ICP4 gene, generating a product of 237 base pairs, was sensitive for ILT diagnosis, and very useful for rapid detection of GaHV-1 in chickens. Fixed tissues allowing histopatological examination and detection of GaHV-1 by PCR, are a good option in areas where farms are located several hundred kilometers away from a diagnostic center, reducing problems with conservation of fresh samples and the risk of virus spread.

14.
Artigo em Inglês | VETINDEX | ID: vti-721726

Resumo

Seventy-eight chickens from a very high poultry density (approximately eight million) region and twelve backyard chickens from neighboring areas were analyzed by histopathology and additional techniques for the presence of the infectious laryngotracheitis virus. The virus distribution was determined in different tissues using immunohistochemistry (IHC) and polymerase chain reaction (PCR). The disease was histopathologically diagnosed in 41.0% (32/78) of the commercial layers. Lesions were mainly characterized by syncytial cells with eosinophilic intranuclear inclusion body formed from the hyperplastic epithelium of the upper respiratory tract, primary and secondary bronchi, and conjunctiva. IHC showed 70% (21/30) positive signal in the larynx/trachea and, 53.8% (14/26) in the lungs, either in epithelial cells or syncytia. In the turbinates and paranasal sinuses, 29.6% (8/27) of samples showed positive signal. PCR detected the following gallid herpesvirus 1-positive percentages: conjunctiva 63.2% (31/49), lungs 57.6% (30/52), turbinates and paranasal sinuses 56% (28/50), and larynx/trachea 50% (39/78). IHC showed to be a useful additional tool for definitive ILT diagnosis, especially during the subacute phase of the disease when syncytial cells with intranuclear inclusion bodies are no longer observed. PCR using specific primers from ICP4 gene, generating a product of 237 base pairs, was sensitive for ILT diagnosis, and very useful for rapid detection of GaHV-1 in chickens. Fixed tissues allowing histopatological examination and detection of GaHV-1 by PCR, are a good option in areas where farms are located several hundred kilometers away from a diagnostic center, reducing problems with conservation of fresh samples and the risk of virus spread.

15.
Rev. bras. ciênc. avic ; 16(4): 359-366, Oct.-Dec. 2014. tab, ilus
Artigo em Inglês | VETINDEX | ID: biblio-1490104

Resumo

Seventy-eight chickens from a very high poultry density (approximately eight million) region and twelve backyard chickens from neighboring areas were analyzed by histopathology and additional techniques for the presence of the infectious laryngotracheitis virus. The virus distribution was determined in different tissues using immunohistochemistry (IHC) and polymerase chain reaction (PCR). The disease was histopathologically diagnosed in 41.0% (32/78) of the commercial layers. Lesions were mainly characterized by syncytial cells with eosinophilic intranuclear inclusion body formed from the hyperplastic epithelium of the upper respiratory tract, primary and secondary bronchi, and conjunctiva. IHC showed 70% (21/30) positive signal in the larynx/trachea and, 53.8% (14/26) in the lungs, either in epithelial cells or syncytia. In the turbinates and paranasal sinuses, 29.6% (8/27) of samples showed positive signal. PCR detected the following gallid herpesvirus 1-positive percentages: conjunctiva 63.2% (31/49), lungs 57.6% (30/52), turbinates and paranasal sinuses 56% (28/50), and larynx/trachea 50% (39/78). IHC showed to be a useful additional tool for definitive ILT diagnosis, especially during the subacute phase of the disease when syncytial cells with intranuclear inclusion bodies are no longer observed. PCR using specific primers from ICP4 gene, generating a product of 237 base pairs, was sensitive for ILT diagnosis, and very useful for rapid detection of GaHV-1 in chickens. Fixed tissues allowing histopatological examination and detection of GaHV-1 by PCR, are a good option in areas where farms are located several hundred kilometers away from a diagnostic center, reducing problems with conservation of fresh samples and the risk of virus spread.


Assuntos
Animais , Aves Domésticas/anatomia & histologia , Aves Domésticas/imunologia , Herpesvirus Galináceo 1/imunologia , Herpesvirus Galináceo 1/patogenicidade , Imuno-Histoquímica , Reação em Cadeia da Polimerase
16.
R. bras. Ci. avíc. ; 16(4): 359-366, Oct.-Dec. 2014. tab, ilus
Artigo em Inglês | VETINDEX | ID: vti-15797

Resumo

Seventy-eight chickens from a very high poultry density (approximately eight million) region and twelve backyard chickens from neighboring areas were analyzed by histopathology and additional techniques for the presence of the infectious laryngotracheitis virus. The virus distribution was determined in different tissues using immunohistochemistry (IHC) and polymerase chain reaction (PCR). The disease was histopathologically diagnosed in 41.0% (32/78) of the commercial layers. Lesions were mainly characterized by syncytial cells with eosinophilic intranuclear inclusion body formed from the hyperplastic epithelium of the upper respiratory tract, primary and secondary bronchi, and conjunctiva. IHC showed 70% (21/30) positive signal in the larynx/trachea and, 53.8% (14/26) in the lungs, either in epithelial cells or syncytia. In the turbinates and paranasal sinuses, 29.6% (8/27) of samples showed positive signal. PCR detected the following gallid herpesvirus 1-positive percentages: conjunctiva 63.2% (31/49), lungs 57.6% (30/52), turbinates and paranasal sinuses 56% (28/50), and larynx/trachea 50% (39/78). IHC showed to be a useful additional tool for definitive ILT diagnosis, especially during the subacute phase of the disease when syncytial cells with intranuclear inclusion bodies are no longer observed. PCR using specific primers from ICP4 gene, generating a product of 237 base pairs, was sensitive for ILT diagnosis, and very useful for rapid detection of GaHV-1 in chickens. Fixed tissues allowing histopatological examination and detection of GaHV-1 by PCR, are a good option in areas where farms are located several hundred kilometers away from a diagnostic center, reducing problems with conservation of fresh samples and the risk of virus spread.(AU)


Assuntos
Animais , Aves Domésticas/anatomia & histologia , Aves Domésticas/imunologia , Herpesvirus Galináceo 1/imunologia , Herpesvirus Galináceo 1/patogenicidade , Imuno-Histoquímica , Reação em Cadeia da Polimerase
17.
Pesqui. vet. bras ; 33(5): 591-596, May 2013. ilus
Artigo em Inglês | VETINDEX | ID: vti-8847

Resumo

A recent (November 2010) outbreak of infectious laryngotracheitis (ILT) in a multi-age laying hen facility in Minas Gerais state, Brazil, is described. Previous ILT outbreak in laying hens was only notified in São Paulo state, Brazil, in 2002. In the outbreak described here, the affected population was approximately eight million hens, with flock sizes ranging from 100,000 to 2,900,000 chickens. The average mortality ranged from 1 to 6%, and morbidity was around 90% (most of the twenty seven farms of the area were positive for ILT virus). Three multi-age laying farms from one company were selected for this report. Clinical signs included prostration, dyspnea, conjunctivitis, occasional swelling of the paranasal sinuses and bloody mucous nasal discharge. Severely affected chickens presented with dyspnea, gasping and became cyanotic before death. At necropsy, these chickens had fibrinous exudate blocking the larynx and the lumen of cranial part of the trachea. In addition, conjunctivitis with intense hyperemia, edema and sinuses with caseous exudate were present. On histopathology, there were marked necrosis and desquamation of respiratory ephitelium and conjunctiva with numerous syncytial cells formation and fibrinous exudate. Moderate to marked non suppurative (especially lymphocytes and plasma cells) infiltration in the lamina propria also was observed. Sixteen out of 20 examined chickens, eosinophilic intranuclear inclusion bodies were observed in the syncytial cells. The DNA extracted from larynx and trachea produced positive PCR results for ILT virus (ILTV) DNA using formalin-fixed, paraffin embedded (FFPE) samples. Amplicons from a small region of ICP4 gene were submitted to sequencing and showed 100% identity with ILTV EU104910.1 (USA strain), 99% with ILTV JN596963.1 (Australian strain) and 91% with ILTV JN580316.1 (Gallid herpesvirus 1 CEO vaccine strain) and JN580315.1 (Gallid herpesvirus 1 TCO vaccine strain).(AU)


Um surto recente (Novembro de 2010) de laringotraqueite infecciosa (LTI) em granjas de postura de múltiplas idades em Minas Gerais, Brasil, é descrito. Um surto de LTI em galinhas de postura havia sido previamente relatado apenas no Estado de São Paulo em 2002. No surto aqui descrito, a população afetada foi de aproximadamente oito milhões de galinhas, com lotes variando de 100.000 a 2.900.000 galinhas. A mortalidade média variou de 1 a 6% e a morbidade atingiu cerca de 90% (a maioria das 27 granjas foram positivas para o virus da LTI). Três granjas com aves de múltiplas idades pertencentes a uma empresa foram selecionadas para o presente relato. Os sinais clinicos incluíram prostração, dispneia, conjuntivite, edema ocasional dos seios paranasais e secreção nasal mucosa e/ou sanguinolenta. As aves severamente afetadas apresentaram acentuada dispneia, aparente engasgo e tornaram-se cianóticas antes da morte. Nestas aves, exsudato fibrinoso denso obstruindo o lúmen da laringe e parte cranial da traqueia foi observado na necropsia. Havia também, conjuntivite com hiperemia intensa e edema, além de sinusite com exsudato caseoso. Na histopatologia, observaram-se necrose e descamação acentuada do epitélio respiratório e da conjuntiva com formação de numerosos sincícios e exsudato fibrinoso. Além disso, infiltrado inflamatório mononuclear (especialmente linfócitos e plasmócitos) moderado a acentuado na lâmina própria foi observado. Corpúsculos de inclusão intranucleares nas células sinciciais foram observados em 16 das 20 aves examinadas. Resultados positivos pela PCR para o virus da LTI foram obtidos de DNA extraído das laringes e traqueias utilizando amostras fixadas em formol e incluidas na parafina. O produto amplificado de uma região pequena do gen ICP4 foi submetido ao sequenciamento e quando comparado com outras sequências depositadas no Genbank mostrou os seguintes resultados: 100% de identidade com uma estirpe do virus de LTI dos Estados Unidos (JN596963.1), 99% de identidade com uma estirpe Australiana e 91% com a estirpe vacinal CEO (JN580316.1) e TCO (JN580315.1).(AU)


Assuntos
Animais , Galinhas/virologia , Herpesvirus Galináceo 1/isolamento & purificação , Reação em Cadeia da Polimerase/veterinária , Dispneia/veterinária
18.
Tese em Português | VETTESES | ID: vtt-217558

Resumo

A laringotraqueíte infecciosa das aves (LTI) é uma doença do trato respiratório, altamente contagiosa, de grande importância por causar perdas econômicas relevante na indústria avícola em todo o mundo. O agente responsável é o Gallid herpesvirus tipo 1 (GaHV 1), responsável pela LTI. O sistema respiratório é o local de predileção para replicação viral. O diagnóstico sorológico da LTI pode ser feito por diferentes testes, conforme preconiza a Organização Mundial de Saúde Animal (OIE), os testes para o diagnóstico da LTI são: Imunodifusão em Gel de Ágar (IDGA), Soroneutralização e ELISA. O ELISA apresenta a vantagem de ser de leitura automatizada e oferecer facilidades para testar grande número de soros. Com isso objetivou-se a padronização e avaliação de um teste ELISA capaz de distinguir os animais naturalmente infectados dos vacinados com vacinas vetorizadas (DIVA) contra o vírus da LTI. Foi utilizado proteína recombinantes do GaHV 1 a gErec para uso em testes ELISA. O teste foi realizado com o antígeno diluído 1:1.600, soros 1:50 e conjugado Anti-galinha IgY 1:100.000. O ponto de corte, a sensibilidade (SeD) e especificidade (SpD) diagnósticas do ELISAgErec foram determinados por meio da análise da curva ROC (Receiver Operating Characteristic), considerando, como verdadeiros positivos, 81 soros de aves de área endêmica não vacinadas para LTI e testados com resultado positivo em um ELISA indireto comercial; os soros considerados verdadeiros negativos (n = 181) foram originários de Granjas de Matrizes Certificadas, livres da LTI, monitoradas para pesquisa de anticorpos contra o VLTI, empregando IDGA comercial. A proteína recombinante gE do VLTI expressa em Escherichia coli quando empregada no ELISA gE DIVA resultou em um teste de elevada especificidade e considerável sensibilidade.


Avian Infectious laryngotracheitis (LTI) is a highly contagious respiratory tract disease of great importance for causing significant economic losses in the poultry industry around the world. The agent responsible is Gallid herpesvirus type 1 (GaHV 1), responsible for LTI. The respiratory system is the predilection for viral replication. The serological diagnosis of LTI can be made by different tests, as recommended by the World Organization for Animal Health (OIE), the tests for the diagnosis of LTI are: Immunodiffusion in Agar Gel (IDGA), Seroneutralization and ELISA. The ELISA has the advantage of being automated reading and offers facilities for testing a large number of sera. The objective was to standardize and evaluate an ELISA test capable of distinguishing naturally infected animals from those vaccinated with vectorized vaccines (DIVA) against the LTI virus. Recombinant proteins from GaHV 1 to gErec were used for use in ELISA tests. The test was performed with antigen diluted 1: 1.600, 1:50 sera and IgY 1: 100.000 Anti-chicken conjugate. The cut-off point, sensitivity (SeD) and diagnostic specificity (SpD) of the ELISAgErec were determined by means of the Receiver Operating Characteristic (ROC) curve analysis, considering 81 sera from non-vaccinated endemic area birds as positive for LTI and tested with positive result in a commercial ELISA; the sera considered as true negative (n = 181) originated from LTI-free Certified Matrix Farms, monitored for VLTI antibody screening using commercial IDGA. The recombinant gE protein of VLTI expressed in Escherichia coli when used in the gE DIVA ELISA resulted in a test of high specificity and considerable sensitivity.

19.
Acta sci. vet. (Impr.) ; 40(3): 01-07, 2012.
Artigo em Inglês | LILACS-Express | VETINDEX | ID: biblio-1457002

Resumo

Background: Infectious laryngotracheitis virus (ILTV) is a member of the family Herpesviridae that has a worldwide distribution, although it is well controlled in areas of intensive production in which periodic outbreaks of the disease occur. ILTV is an important respiratory pathogen of chickens that may cause severe or mild disease in layers and broilers. Severe disease is characterized by respiratory depression, gasping, expectoration of bloody exudate and high mortality. Mild diseased chickens exhibit milder clinical signs and low mortality, and laboratory techniques are mandatory for a fi nal diagnosis. Several techniques have been described for the detection of ILTV, however they have disadvantages that constrains their use in routine diagnosis. Viral multiplication is limited to respiratory tissue, which makes the trachea the ideal site to look for the virus. The purpose of the present study was to develop a sensitive and specifi c nested Polymerase Chain Reaction (PCR) protocol to detect ILTV DNA directly from tracheal swabs of naturally or experimentally infected chickens.Materials, Methods & Results: The nested-PCR was carried out with two sets of primers selected from a portion of the ILTV thymidine kinase gene. PCR sensitivity was determined by using fi ve-fold serial dilutions of a commercial laryngotracheitis vaccine. PCR was specifi c as determined by testing


Background: Infectious laryngotracheitis virus (ILTV) is a member of the family Herpesviridae that has a worldwide distribution, although it is well controlled in areas of intensive production in which periodic outbreaks of the disease occur. ILTV is an important respiratory pathogen of chickens that may cause severe or mild disease in layers and broilers. Severe disease is characterized by respiratory depression, gasping, expectoration of bloody exudate and high mortality. Mild diseased chickens exhibit milder clinical signs and low mortality, and laboratory techniques are mandatory for a fi nal diagnosis. Several techniques have been described for the detection of ILTV, however they have disadvantages that constrains their use in routine diagnosis. Viral multiplication is limited to respiratory tissue, which makes the trachea the ideal site to look for the virus. The purpose of the present study was to develop a sensitive and specifi c nested Polymerase Chain Reaction (PCR) protocol to detect ILTV DNA directly from tracheal swabs of naturally or experimentally infected chickens.Materials, Methods & Results: The nested-PCR was carried out with two sets of primers selected from a portion of the ILTV thymidine kinase gene. PCR sensitivity was determined by using fi ve-fold serial dilutions of a commercial laryngotracheitis vaccine. PCR was specifi c as determined by testing

20.
Acta sci. vet. (Impr.) ; 40(3): Pub. 1055, 2012. tab, ilus
Artigo em Inglês | VETINDEX | ID: biblio-1373620

Resumo

Background: Infectious laryngotracheitis virus (ILTV) is a member of the family Herpesviridae that has a worldwide distribution, although it is well controlled in areas of intensive production in which periodic outbreaks of the disease occur. ILTV is an important respiratory pathogen of chickens that may cause severe or mild disease in layers and broilers. Severe disease is characterized by respiratory depression, gasping, expectoration of bloody exudate and high mortality. Mild diseased chickens exhibit milder clinical signs and low mortality, and laboratory techniques are mandatory for a final diagnosis. Several techniques have been described for the detection of ILTV, however they have disadvantages that constrains their use in routine diagnosis. Viral multiplication is limited to respiratory tissue, which makes the trachea the ideal site to look for the virus. The purpose of the present study was to develop a sensitive and specific nested Polymerase Chain Reaction (PCR) protocol to detect ILTV DNA directly from tracheal swabs of naturally or experimentally infected chickens. Materials, Methods & Results: The nested-PCR was carried out with two sets of primers selected from a portion of the ILTV thymidine kinase gene. PCR sensitivity was determined by using five-fold serial dilutions of a commercial laryngotracheitis vaccine. PCR was specific as determined by testing related respiratory viruses (pathogens of chickens), ILTV strain, and field isolates. Nested-PCR was 250 times more sensitive than virus isolation (VI). To further validate the ability of this assay to detect ILTV from tracheal swabs, experimentally infected chickens and ILTV suspect cases were examined by VI, PCR, and histopathology. VI and nested-PCR both detected virus in tracheas during all the experimental period. With one exception, all positive samples by VI were also positive by the nested-PCR. However, nested-PCR detected 5 additional positive samples in the end of the experimental period. Through direct histopathology, typical syncytia and inclusion bodies were found in only two samples. In the clinical cases of respiratory illness, VI detected ILTV positive samples in 4 out of the 8 flocks with respiratory illness and histopathological analyses detected 3 flocks but the nested-PCR detected 5 positive fl ocks including those positive by VI and histopathology. Discussion: In the experimental infection, VI and PCR both detected ILTV in the majority of the samples but PCR detected some additional positive samples close to the end of the experimental period. By comparison of the PCR with VI sensitivity, it can be concluded that the protocol here described has a greater advantage over the previously described protocols that afford a direct comparison. Histopathology was the least sensitive test, since viral inclusion bodies and syncytial cells were only observed in two tracheal sections and a possible explanation for this result may be that necrosis and desquamation destroy infected epithelium. In the detection of the virus from clinical cases, the nested-PCR also detected a greater number of positive samples than VI and histopathology. Comparison of the nested-PCR with VI in experimentally infected broilers indicates that the two diagnostic tests are very efficient to detect ILTV in the early time of infection. However, VI tests in late infection may be not as sensitive as the nested-PCR if majority of the ILTV have been inactivated or become latent. Two distinctive sequences were obtained from the positive controls and field isolates. The sequences were specific to ILTV since they had a minimum of 99.5% similarity with previously described strains. The assay described in the present study indicates that the nested-PCR protocol is more sensitive than previously described tests and can replace histopathology and virus isolation with advantage.


Assuntos
Animais , Doenças das Aves Domésticas/virologia , Galinhas/virologia , Reação em Cadeia da Polimerase/veterinária , Herpesvirus Galináceo 1/isolamento & purificação , Infecções por Herpesviridae/veterinária
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