Tracheal post-vaccinal reaction to different strains of Newcastle disease vírus / Reação traqueal pós-vacinal à diferentes cepas do vírus da doença de Newcastle

The aim of the present study was to evaluate the post-vaccinal reaction to two lentogenic vaccine strains of Newcatle disease virus (NDV) and a recombinant turkey herpesvirus (rHVT) vaccine expressing the fusion glycoprotein of NDV in broiler chickens through histomorphometric and histopathologic analyses of the trachea. The experiment involved 245 chicks housed in randomized blocks with three different enclosures under controlled conditions of temperature, light and ventilation. Each enclosure represented a vaccine strain and was divided into groups according to the administration route. Each block also had its own control group composed of unvaccinated birds. The vaccine strains PHY.LMV.42 (PL42) and La Sota (LS) were selected according to the Intracerebral Pathogenicity Index (ICPI) and the rHVT-NDV Serotype 3 strain (ST3) was selected for representing non-NDV infection. At two, four, seven, 14 and 21 days post vaccination, fragments from the middle third of the trachea were collected and submitted to routine histological processing. For the histomorphometric analysis, the slides were photographed, and the thickness of the tracheal mucosa was measured. Statistical analysis involved two-way ANOVA and Tukey's post-hoc test with a 5% significance level. For the histopathological evaluation, lesions were described as to the degree of intensity and distribution. At four and 14 days post vaccination with the LS strain administered by the ocular route, the means of thickening of the tracheal mucosa (20.85±7.31µm and 26.97±5.50µm, respectively) were significantly higher (p<0.05) than for all other strains, which was related to the severe histopathological lesions found in this group, characterized by hyperemia, hyperplasia of the mucous glands, moderate deciliation and multifocal lymphohistiocytic inflammatory infiltrate. At 21 days, broiler chickens vaccinated with the ST3 strain showed more discrete lesions and less thickening of the tracheal mucosa (23.23±7.62µm; p<0.05) in comparison with other studied strains. The lesions found in this group were only hemorrhage, deciliation and mild focal lymphocytic inflammatory infiltrate. The results of the histomorphometry and histopathology of the trachea indicated that vaccination with rHVT-NDV Serotype 3 strain induced lower degree post-vaccine tracheal lesions compared to other vaccine strains analyzed in this study.

Objetivou-se avaliar a reação pós-vacinal de duas estirpes lentogênicas do vírus da doença de Newcastle (VDN) e uma vacina recombinante de herpesvirus de perus (rHVT) que expressa a glicoproteína de fusão de VDN em frangos de corte por meio da histomorfometria e histopatologia da traqueia. Foram utilizados 245 pintos alojados em blocos ao acaso, sendo três galpões distintos em condições controladas de temperatura, luz e ventilação. Cada galpão representou uma cepa vacinal, onde foram divididos por grupos de acordo com a via de administração. Todos os blocos possuíam um grupo controle composto por aves não vacinadas. As cepas vacinais PHY.LMV.42 (PL42) e La Sota (LS) utilizadas foram selecionadas de acordo com o Índice de Patogenicidade Intracerebral (IPIC) e a cepa Sorotipo 3 (ST3), da vacina rHVT-VDN foi selecionada por não representar infecção do VDN. Aos dois, quarto, sete, 14 e 21 dias pós-vacinação, fragmentos do terço médio da traqueia foram coletados e posteriormente processados conforme rotina histológica. Para análise histomorfométrica da mucosa traqueal, as lâminas foram fotografadas e realizadas as mensurações da espessura da mucosa traqueal sendo aplicado teste de análise de variância a dois critérios (ANOVA) e utilizando o post-hoc de Tukey com nível de significância de 5%. Para a avaliação histopatológica foram observadas a presença de lesões microscópicas e estas foram descritas quanto ao grau de intensidade e distribuição. Aos quatro e quatorze dias pós-vacinação com a cepa LS administrada por via ocular, as médias do espessamento da mucosa traqueal (20,85±7,31µm e 26,97±5,50µm, respectivamente) foram significativamente maiores (p<0,05) quando comparada a todas as demais cepas utilizadas, isto se deve às severas lesões histopatológicas encontrados neste grupo, caracterizadas por hiperemia, hiperplasia das glândulas mucosas, deciliação moderada e infiltrado inflamatório linfohistiocitário multifocal moderado. Já aos 21 dias as aves vacinadas com a cepa ST3 apresentaram lesões mais discretas e menor espessamento da mucosa da traqueia (23,23±7,62µm; p<0,05) em comparação às demais cepas estudadas. As lesões encontradas neste grupo foram apenas hemorragia, deciliação e infiltrado inflamatório linfocitário focal discreto. Os resultados da histomorfometria e da histopatologia da traqueia indicou que a vacinação com a rHVT-NDV, cepa Sorotipo 3 induziu menor grau de lesões pós-vacinais na traqueia comparada a outras cepas vacinais analisadas nesse estudo.

Marek's disease in roosters in the Potiguar semi-arid region

Background: Marek's disease (MD) is a transmissible disease in chickens caused by Gallid alphaherpesvirus 2 (GaHV-2). The infection is characterized by lymphocyte cellular infiltrates in peripheral nerves and other organs and tissues, including the skin; which can lead to dysfunction causing progressive asymmetric paresis and complete spastic paralysis of body extremities. Dermatitis and cardiac myositis caused by GaHV-2 in free-range chickens has rarely been described in Brazil. This reports the occurrence of the disease with a confirmatory molecular diagnosis in free-range poultry showing signs of dermatitis, poor performance, and cachexia and no mortality in the semi-arid Potiguar region. Cases: Twenty roosters of the Shamo lineage, among a brood of 42 birds, had a history of progressive weight loss and skin lesions. Two birds with poor body condition, erythema, and scaling of the skin in the head and cervical regions were sent for clinical care. All birds were between 12 and 18 months of age and were vaccinated against Newcastle disease and Fowlpox with only a few receiving vaccines against MD and Gumboro disease. According to the owner's report, some birds were previously kept outdoors, and when they were transferred to a small shed with little air circulation, they began to develop clinical signs after approximately 15 days. The first signs of the disease were also reported to have appeared 2.5 months before clinical care and, in the meantime, several treatments were instituted without success. Owing to the general condition of the animals and inconclusive clinical suspicion, the birds were subjected to euthanasia and necropsy. Tissue samples were collected for histopathological and polymerase chain reaction analyses to search for the GaHV-2 DNA meq gene. The main clinicopathological findings were erythema (47%, 20/42) and desquamation of skin and mild, prominent white multifocal areas in the heart. Histopathology revealed infiltration of pleomorphic lymphoblastic cells in the skin, heart, and sciatic nerve. The amplification of the L-meq and meq oncoprotein genes in these organs and in the liver, confirmed the infection by GaHV-2, consistent with that of a field strain. Discussion: MD was confirmed based on the macroscopic and histological lesions, and with the detection of GaHV-2 DNA in the affected tissues. The unusual clinical presentation represented an initial challenge for diagnosis. The clinical history was important to lead to the suspicion of MD, as roosters initiated clinical signs 15 days after they were transferred to a small shed with poor air circulation. This probably favored the high viral concentration and disease transmission among susceptible birds in the brood because the feather follicle is the primary site of viral replication for transmission; and desquamation of infected epithelial cells favor airborne horizontal transmission to susceptible chickens. The roosters had not been vaccinated against MD, which probably favored the infection, as vaccination is known to be a fundamental approach for MD control for effective growth of the poultry industry. Clinical findings and lesions, together with viral molecular detection, were fundamental for the diagnosis, a premise for the application of adequate prevention and control measures for the disease in breeding. This is the first report of MD with a confirmatory molecular diagnosis in northeastern Brazil.

Acute intoxication with single oral dose of ochratoxin A (OTA) causes leukopenia, heteropenia, lymphopenia and lymphoid depletion in the bursa of Fabricius in broiler chicks / Intoxicação aguda com dose oral única de ocratoxina A (OTA) causa leucopenia, heteropenia, linfopenia e depleção linfoide na bolsa de Fabricius em pintainhos de corte

Ochratoxin A (OTA) is a mycotoxin produced by species of Penicillium and Aspergillus, agricultural product contaminants. Chronic and sub-chronic OTA intoxication by chickens ingesting contaminated feed, leads to health damages due to its hepatotoxic, nephrotoxic, cytotoxic, immunotoxic, gastrotoxic, and possibly carcinogenic effects. As there are few data on acute intoxication, the present study evaluated the effects of a single acute OTA intoxication dose on immunological and hematological parameters in chicks. Sixteen one-day-old chicks were used, separated into two groups (n=8). A single dose of OTA (1400 µg kg-1 body weight) was administered, via gavage, for the OTA group and one dose of sterile PBS for the control group. On the 13th day, blood samples were collected to assess hematological and biochemical parameters, and on the 14th day, euthanasia and collection of lymphoid organs were performed. The animals of the OTA group demonstrated a significant decrease in total circulating leukocytes (p<0.001) with heteropenia (p<0.001) and lymphopenia (p=0.023), decrease hematocrit (p=0.020), hemoglobin (p=0.032), and plasma IgA (p =0.044), and increased plasma uric acid level (p=0.045), in relation to the control group. In addition, the animals intoxicated with OTA showed depletion of lymphoid cells in the bursa of Fabricius (p=0.016), but not in the thymus or spleen (p>0.05), compared to the control. For the other parameters: total plasma proteins, plasma IgY levels, and anti-Newcastle Disease Virus (NDV) vaccine titers from matrices, there were no significant differences between the analyzed groups (p>0.05), although there was a worsening tendency in contaminated animals. In conclusion, even a single acute OTA intoxication at a high dose, leads to the suppression of the systemic immune response, also affecting some hematological or biochemical parameters in chicks.

Ocratoxina A (OTA) é uma micotoxina produzida por espécies de Penicillium e Aspergillus, contaminantes de produtos agrícolas. Intoxicação crônica e subcrônica por OTA em frangos que ingerem ração contaminada, levam à danos à saúde devido aos seus efeitos hepatotóxicos, nefrotóxicos, citotóxicos, imunotóxicos, gastrotóxicos e possivelmente carcinogênicos. Como há poucos dados sobre intoxicação aguda, o presente estudo avaliou os efeitos de uma dose única de intoxicação aguda por OTA sobre parâmetros imunológicos e hematológicos em pintainhos. Foram utilizados 16 pintainhos de um dia de idade, separados em dois grupos (n=8). Uma dose única de OTA (1400 µg kg-1 de peso corporal) foi administrada, via gavagem, para o grupo OTA e uma dose de PBS estéril para o grupo controle. No 13º dia foram coletadas amostras de sangue para avaliação dos parâmetros hematológicos e bioquímicos, e no 14º dia foi realizada a eutanásia e coleta de órgãos linfoides. Os animais do grupo OTA demonstraram diminuição significativa do total de leucócitos circulantes (p<0,001) com heteropenia (p<0,001) e linfopenia (p=0,023), diminuição do hematócrito (p=0,020), hemoglobina (p=0,032) e IgA plasmática (p=0,044) e aumento do nível plasmático de ácido úrico (p=0,045), em relação ao grupo controle. Além disso, os animais intoxicados com OTA apresentaram depleção de células linfóides na bolsa de Fabricius (p=0,016), mas não no timo ou baço (p>0,05), em relação ao controle. Para os demais parâmetros: proteínas totais do plasma, níveis plasmáticos de IgY e títulos de vacinas contra o Vírus da Doença de Newcastle (NDV) das matrizes, não houve diferenças significativas entre os grupos analisados (p>0,05), embora tenha havido uma tendência de piora nos animais contaminados. Em conclusão, mesmo uma intoxicação única aguda por OTA em alta dose, leva à supressão da resposta imune sistêmica, afetando também alguns parâmetros hematológicos ou bioquímicos em pintainhos.

Development of a sandwich enzyme-linked immunosorbent assay based on single-domain antibody for detecting goose parvovirus infection / [Desenvolvimento de um ensaio imunoadsorvente ligado a enzima sandwich baseado em anticorpo de domínio único para detecção de infecção por parvovírus de ganso]

A infecção por parvovírus de ganso (GPV) é uma doença infecciosa altamente patogênica em gansinhos e patinhos de Muscovy. Para detectar o antígeno GPV, desenvolvemos um novo ensaio imunoenzimático (ELISA) sanduíche usando um anticorpo de domínio único de cadeia pesada específico contra a proteína GPV NS1 como anticorpo de detecção. Os limites de detecção da proteína GST-NS1 e do título do vírus da cepa GPV H1 foram 5 ng/mL e 102,9 TCID50/mL, respectivamente. O ELISA sanduíche foi específico para GPV sem reatividade cruzada com outros vírus comuns de ganso, incluindo vírus Tembusu, circovírus de ganso, adenovírus de aves, vírus Newcastle ou vírus H9 da gripe aviária. Um total de 118 amostras de swab cloacal foram usadas para detectar o antígeno GPV usando o ELISA sanduíche e reação em cadeia da polimerase com uma taxa de coincidência de 91,5%. A sensibilidade e especificidade do ELISA sanduíche foram de 91,6% e 91,4%, respectivamente. Esses resultados sugerem que este ELISA sanduíche pode ser aplicado para detectar GPV.

Molecular diagnosis of avian viruses in grassland passerines and captive yellow cardinals Gubernatrix cristata in Brazil / Diagnóstico molecular de vírus aviários em passeriformes campestres e cardeais-amarelos Gubernatrix cristata cativos no Brasil

Avian influenza viruses (AIVs), Newcastle disease virus (NDV), West Nile virus (WNV), adenovirus (AV) and herpesvirus (HV) play an important role in the health of human and animal populations. However, knowledge of the prevalence of these viruses in wild birds is restricted to some groups (e.g. shorebirds) or regions worldwide. Information on grassland birds of South America, which is essential for their conservation, is scarce. The objectives of the present study were to evaluate occurrences of AIV, NDV, WNV, AV and HV for the first time in a bird community of a unique protected area in southern Brazil, which is home for the critically endangered yellow cardinal (Gubernatrix cristata), and captive yellow cardinals from fauna maintainers of the Brazilian Captive Program of the Yellow Cardinal. Passerine species of wild life were caught, identified and samples (swabs) were collected from the oropharynx and cloaca of 64 passerines of 26 species (including 3 yellow cardinals) and 30 yellow cardinals of captive, for molecular diagnosis. The samples were subjected to RNA and DNA extraction and the real-time polymerase chain reaction (RT-PCR) for AIV, NDV and WNV and nested PCR for AV and HV. One yellow cardinal of captive presented a positive result for AV, this result is important for planning, managing natural attributes and making decisions in relation to integrated conservation of threatened species. This is the first report of AV in yellow cardinal and epidemiological investigation of viruses in wild passerines of the Pampa biome, in Rio Grande do Sul, Brazil.(AU)

Os vírus da gripe aviária (VGA), vírus da doença de Newcastle (VDN), vírus do Nilo Ocidental (VNO), adenovírus (AV) e herpesvírus (HV) desempenham um papel importante na saúde das populações humana e animal. No entanto, o conhecimento da prevalência desses vírus em aves selvagens é restrito a alguns grupos (por exemplo, aves limícolas) ou regiões em todo o mundo. As informações sobre as aves campestres da América do Sul, essenciais para a sua conservação, são escassas. Os objetivos do presente estudo foram avaliar a ocorrência de VGA, VDN, VNO, AV e HV pela primeira vez em uma comunidade de aves de uma área única protegida no Sul do Brasil, que abriga o cardeal-amarelo (Gubernatrix cristata) criticamente ameaçado de extinção e em cardeais-amarelos de cativeiro dos mantenedores de fauna do Programa Brasileiro de Cativeiro do Cardeal-amarelo. Espécies de passeriformes silvestres foram capturadas, identificadas e amostras (swabs) foram coletadas da orofaringe e cloaca de 64 passeriformes de 26 espécies (incluindo 3 cardeais-amarelos) e 30 cardeais-amarelos de cativeiro, para diagnóstico molecular. As amostras foram submetidas à extração de RNA e DNA e à reação em cadeia da polimerase em tempo real (RT-PCR) para VGA, VDN e VNO e nested PCR para AV e HV. Um cardeal-amarelo de cativeiro apresentou resultado positivo para AV, este resultado é importante para o planejamento, manejo dos atributos naturais e tomada de decisões em relação à conservação integrada de espécies ameaçadas. Este é o primeiro relato de AV em cardeal-amarelo e de investigação epidemiológica de vírus em passeriformes silvestres do bioma Pampa, no Rio Grande do Sul, Brasil.(AU)

Molecular diagnosis of avian viruses in grassland passerines and captive yellow cardinals Gubernatrix cristata in Brazil / Diagnóstico molecular de vírus aviários em passeriformes campestres e cardeais-amarelos Gubernatrix cristata cativos no Brasil

Avian influenza viruses (AIVs), Newcastle disease virus (NDV), West Nile virus (WNV), adenovirus (AV) and herpesvirus (HV) play an important role in the health of human and animal populations. However, knowledge of the prevalence of these viruses in wild birds is restricted to some groups (e.g. shorebirds) or regions worldwide. Information on grassland birds of South America, which is essential for their conservation, is scarce. The objectives of the present study were to evaluate occurrences of AIV, NDV, WNV, AV and HV for the first time in a bird community of a unique protected area in southern Brazil, which is home for the critically endangered yellow cardinal (Gubernatrix cristata), and captive yellow cardinals from fauna maintainers of the Brazilian Captive Program of the Yellow Cardinal. Passerine species of wild life were caught, identified and samples (swabs) were collected from the oropharynx and cloaca of 64 passerines of 26 species (including 3 yellow cardinals) and 30 yellow cardinals of captive, for molecular diagnosis. The samples were subjected to RNA and DNA extraction and the real-time polymerase chain reaction (RT-PCR) for AIV, NDV and WNV and nested PCR for AV and HV. One yellow cardinal of captive presented a positive result for AV, this result is important for planning, managing natural attributes and making decisions in relation to integrated conservation of threatened species. This is the first report of AV in yellow cardinal and epidemiological investigation of viruses in wild passerines of the Pampa biome, in Rio Grande do Sul, Brazil.(AU)

Os vírus da gripe aviária (VGA), vírus da doença de Newcastle (VDN), vírus do Nilo Ocidental (VNO), adenovírus (AV) e herpesvírus (HV) desempenham um papel importante na saúde das populações humana e animal. No entanto, o conhecimento da prevalência desses vírus em aves selvagens é restrito a alguns grupos (por exemplo, aves limícolas) ou regiões em todo o mundo. As informações sobre as aves campestres da América do Sul, essenciais para a sua conservação, são escassas. Os objetivos do presente estudo foram avaliar a ocorrência de VGA, VDN, VNO, AV e HV pela primeira vez em uma comunidade de aves de uma área única protegida no Sul do Brasil, que abriga o cardeal-amarelo (Gubernatrix cristata) criticamente ameaçado de extinção e em cardeais-amarelos de cativeiro dos mantenedores de fauna do Programa Brasileiro de Cativeiro do Cardeal-amarelo. Espécies de passeriformes silvestres foram capturadas, identificadas e amostras (swabs) foram coletadas da orofaringe e cloaca de 64 passeriformes de 26 espécies (incluindo 3 cardeais-amarelos) e 30 cardeais-amarelos de cativeiro, para diagnóstico molecular. As amostras foram submetidas à extração de RNA e DNA e à reação em cadeia da polimerase em tempo real (RT-PCR) para VGA, VDN e VNO e nested PCR para AV e HV. Um cardeal-amarelo de cativeiro apresentou resultado positivo para AV, este resultado é importante para o planejamento, manejo dos atributos naturais e tomada de decisões em relação à conservação integrada de espécies ameaçadas. Este é o primeiro relato de AV em cardeal-amarelo e de investigação epidemiológica de vírus em passeriformes silvestres do bioma Pampa, no Rio Grande do Sul, Brasil.(AU)

Molecular diagnosis of avian viruses in grassland passerines and captive yellow cardinals Gubernatrix cristata in Brazil

ABSTRACT: Avian influenza viruses (AIVs), Newcastle disease virus (NDV), West Nile virus (WNV), adenovirus (AV) and herpesvirus (HV) play an important role in the health of human and animal populations. However, knowledge of the prevalence of these viruses in wild birds is restricted to some groups (e.g. shorebirds) or regions worldwide. Information on grassland birds of South America, which is essential for their conservation, is scarce. The objectives of the present study were to evaluate occurrences of AIV, NDV, WNV, AV and HV for the first time in a bird community of a unique protected area in southern Brazil, which is home for the critically endangered yellow cardinal (Gubernatrix cristata), and captive yellow cardinals from fauna maintainers of the Brazilian Captive Program of the Yellow Cardinal. Passerine species of wild life were caught, identified and samples (swabs) were collected from the oropharynx and cloaca of 64 passerines of 26 species (including 3 yellow cardinals) and 30 yellow cardinals of captive, for molecular diagnosis. The samples were subjected to RNA and DNA extraction and the real-time polymerase chain reaction (RT-PCR) for AIV, NDV and WNV and nested PCR for AV and HV. One yellow cardinal of captive presented a positive result for AV, this result is important for planning, managing natural attributes and making decisions in relation to integrated conservation of threatened species. This is the first report of AV in yellow cardinal and epidemiological investigation of viruses in wild passerines of the Pampa biome, in Rio Grande do Sul, Brazil.

RESUMO: Os vírus da gripe aviária (VGA), vírus da doença de Newcastle (VDN), vírus do Nilo Ocidental (VNO), adenovírus (AV) e herpesvírus (HV) desempenham um papel importante na saúde das populações humana e animal. No entanto, o conhecimento da prevalência desses vírus em aves selvagens é restrito a alguns grupos (por exemplo, aves limícolas) ou regiões em todo o mundo. As informações sobre as aves campestres da América do Sul, essenciais para a sua conservação, são escassas. Os objetivos do presente estudo foram avaliar a ocorrência de VGA, VDN, VNO, AV e HV pela primeira vez em uma comunidade de aves de uma área única protegida no Sul do Brasil, que abriga o cardeal-amarelo (Gubernatrix cristata) criticamente ameaçado de extinção e em cardeais-amarelos de cativeiro dos mantenedores de fauna do Programa Brasileiro de Cativeiro do Cardeal-amarelo. Espécies de passeriformes silvestres foram capturadas, identificadas e amostras (swabs) foram coletadas da orofaringe e cloaca de 64 passeriformes de 26 espécies (incluindo 3 cardeais-amarelos) e 30 cardeais-amarelos de cativeiro, para diagnóstico molecular. As amostras foram submetidas à extração de RNA e DNA e à reação em cadeia da polimerase em tempo real (RT-PCR) para VGA, VDN e VNO e nested PCR para AV e HV. Um cardeal-amarelo de cativeiro apresentou resultado positivo para AV, este resultado é importante para o planejamento, manejo dos atributos naturais e tomada de decisões em relação à conservação integrada de espécies ameaçadas. Este é o primeiro relato de AV em cardeal-amarelo e de investigação epidemiológica de vírus em passeriformes silvestres do bioma Pampa, no Rio Grande do Sul, Brasil.

Viral distribution of Newcastle disease virus genotype VII in different organs of broiler chickens

The poultry industry in Egypt is still threatened by Newcastle disease despite intensive vaccination programs. Bothvaccinated and unvaccinated poultry flocks have experienced Newcastle disease virus (NDV) genotype VII outbreakswithin the last few years. This study was performed to investigate the pathogenesis of NDV genotype VII in differentorgans of broiler chickens. Fifty, 1-day-old chicks were divided into 2 equal groups with 25 animals in each group. Group 1served as the non-infected (negative control) group, while group 2 was infected by intranasal inoculation of 0.1 mlcontaining 106 EID50 of NDV genotype VII. Three chicks were sacrificed from each group at 2, 5, and 10 days postinfection (dpi). Tissue sections from the nasal conchae, larynx, trachea, lungs, heart, kidneys, and brain were collected forhistopathology and immunohistochemistry. Quantitative RT-PCR (qRT-PCR) was also performed on the tracheal samples.The infected group showed severe respiratory signs and had greenish-colored diarrhea. Mortalities were 6, 4, 6, and 2 chicksat 5, 6, 7, and 9 dpi, respectively. Grossly, congestion of the mucosa of the trachea and larynx was recorded at 5 dpi.Histopathological examination of different organs revealed tracheitis, pneumonia, laryngitis, nephritis, brain perivascularcuffing, and neuronal degeneration. NDV antigen was detected by IHC in all examined organs except the brain. Strong viralantigen expression by IHC was observed at 5 and 7 dpi in most of the studied organs. Viral antigen expression was alsodetected in the endothelial cells of blood vessels, cilia, surface epithelium, and goblet cells of the nasal conchae, larynx, andtrachea in addition to the cytoplasm of cardiomyocytes and in the epithelium lining the renal tubules.

Viral distribution of Newcastle disease virus genotype VII in different organs of broiler chickens

The poultry industry in Egypt is still threatened by Newcastle disease despite intensive vaccination programs. Bothvaccinated and unvaccinated poultry flocks have experienced Newcastle disease virus (NDV) genotype VII outbreakswithin the last few years. This study was performed to investigate the pathogenesis of NDV genotype VII in differentorgans of broiler chickens. Fifty, 1-day-old chicks were divided into 2 equal groups with 25 animals in each group. Group 1served as the non-infected (negative control) group, while group 2 was infected by intranasal inoculation of 0.1 mlcontaining 106 EID50 of NDV genotype VII. Three chicks were sacrificed from each group at 2, 5, and 10 days postinfection (dpi). Tissue sections from the nasal conchae, larynx, trachea, lungs, heart, kidneys, and brain were collected forhistopathology and immunohistochemistry. Quantitative RT-PCR (qRT-PCR) was also performed on the tracheal samples.The infected group showed severe respiratory signs and had greenish-colored diarrhea. Mortalities were 6, 4, 6, and 2 chicksat 5, 6, 7, and 9 dpi, respectively. Grossly, congestion of the mucosa of the trachea and larynx was recorded at 5 dpi.Histopathological examination of different organs revealed tracheitis, pneumonia, laryngitis, nephritis, brain perivascularcuffing, and neuronal degeneration. NDV antigen was detected by IHC in all examined organs except the brain. Strong viralantigen expression by IHC was observed at 5 and 7 dpi in most of the studied organs. Viral antigen expression was alsodetected in the endothelial cells of blood vessels, cilia, surface epithelium, and goblet cells of the nasal conchae, larynx, andtrachea in addition to the cytoplasm of cardiomyocytes and in the epithelium lining the renal tubules.(AU)

Monitoring of Newcastle disease in poultry at migratory birds landing sites: Mangue Seco and Cacha Pregos between 2013 and 2014 / Monitoramento da doença de Newcastle em aves domésticas nos sítios de pouso de aves migratórias: Mangue Seco e Cacha Pregos entre 2013 e 2014

The poultry industry has been considered one of the most efficient agricultural activities, placing Brazil in the ranking of the largest producers of chicken meat. However, a threat to the poultry production chain is the entrance of Newcastle disease virus (NDV) in the country, which would bring huge economic and social losses. Monitoring of the virus was conducted in domestic poultry (Gallus gallus domesticus) farms on the migratory birds landing sites Mangue Seco and Cacha Pregos between 2013 and 2014 to control Newcastle disease (NCD) in these locations. Activities in health education, filling the questionnaire to define the sanitary profile of the farms, georeferenced registration and collection of blood samples, cloacal and tracheal swabs of the backyard birds were the epidemiological surveillance actions performed. A total of 133 serum samples were analyzed in Mangue Seco and 81 in Cacha Pregos. The results showed that both Mangue Seco (63.4%) and Cacha Pregos (88.9%) presented reactive animals for the NDV. The results of real-time polymerase chain reaction (RT-PCR) and viral isolation analyses were negative, proving that the domestic poultry were not eliminating the virus at the time of sample collection. The high percentage of reactive animals by indirect ELISA test in both epidemiological units studied suggests the presence of NDV circulating lentogenic strain, since there was no death registration and the birds did not have characteristic symptoms of the disease.(AU)

A avicultura tem sido considerada uma das atividades agrícolas mais eficientes, colocando o Brasil no ranking dos maiores produtores de carne de frango. No entanto, uma ameaça à cadeia produtiva da avicultura é a entrada do vírus da doença de Newcastle (NDV) no país, o que acarretaria enormes prejuízos econômicos e sociais. O monitoramento do vírus foi realizado em granjas de aves domésticas (Gallus gallus domesticus) nos locais de desembarque de aves migratórias de Mangue Seco e Cacha Pregos entre 2013 e 2014 para controlar a doença de Newcastle (DCNT) nesses locais. Atividades de educação em saúde, preenchimento de questionário para definição do perfil sanitário das fazendas, cadastro georreferenciado e coleta de amostras de sangue e swabs cloacal e traqueal de aves de quintal foram as ações de vigilância epidemiológica realizadas. Um total de 133 amostras de soro foram analisadas em Mangue Seco e 81 em Cacha Pregos. Os resultados mostraram que tanto Mangue Seco (63,4%) quanto Cacha Pregos (88,9%) apresentaram animais reativos para o NDV. Os resultados da reação em cadeia da polimerase em tempo real (RT-PCR) e das análises de isolamento viral foram negativos, comprovando que as aves domésticas não estavam eliminando o vírus no momento da coleta das amostras. O alto percentual de animais reativos pelo teste ELISA indireto em ambas as unidades epidemiológicas estudadas sugere a presença de cepa lentogênica circulante de NDV, uma vez que não houve registro de óbito e as aves não apresentavam sintomas característicos da doença.(AU)

Monitoring of Newcastle disease in poultry at migratory birds landing sites: Mangue Seco and Cacha Pregos between 2013 and 2014 / Monitoramento da doença de Newcastle em aves domésticas nos sítios de pouso de aves migratórias: Mangue Seco e Cacha Pregos entre 2013 e 2014

The poultry industry has been considered one of the most efficient agricultural activities, placing Brazil in the ranking of the largest producers of chicken meat. However, a threat to the poultry production chain is the entrance of Newcastle disease virus (NDV) in the country, which would bring huge economic and social losses. Monitoring of the virus was conducted in domestic poultry (Gallus gallus domesticus) farms on the migratory birds landing sites Mangue Seco and Cacha Pregos between 2013 and 2014 to control Newcastle disease (NCD) in these locations. Activities in health education, filling the questionnaire to define the sanitary profile of the farms, georeferenced registration and collection of blood samples, cloacal and tracheal swabs of the backyard birds were the epidemiological surveillance actions performed. A total of 133 serum samples were analyzed in Mangue Seco and 81 in Cacha Pregos. The results showed that both Mangue Seco (63.4%) and Cacha Pregos (88.9%) presented reactive animals for the NDV. The results of real-time polymerase chain reaction (RT-PCR) and viral isolation analyses were negative, proving that the domestic poultry were not eliminating the virus at the time of sample collection. The high percentage of reactive animals by indirect ELISA test in both epidemiological units studied suggests the presence of NDV circulating lentogenic strain, since there was no death registration and the birds did not have characteristic symptoms of the disease.(AU)

A avicultura tem sido considerada uma das atividades agrícolas mais eficientes, colocando o Brasil no ranking dos maiores produtores de carne de frango. No entanto, uma ameaça à cadeia produtiva da avicultura é a entrada do vírus da doença de Newcastle (NDV) no país, o que acarretaria enormes prejuízos econômicos e sociais. O monitoramento do vírus foi realizado em granjas de aves domésticas (Gallus gallus domesticus) nos locais de desembarque de aves migratórias de Mangue Seco e Cacha Pregos entre 2013 e 2014 para controlar a doença de Newcastle (DCNT) nesses locais. Atividades de educação em saúde, preenchimento de questionário para definição do perfil sanitário das fazendas, cadastro georreferenciado e coleta de amostras de sangue e swabs cloacal e traqueal de aves de quintal foram as ações de vigilância epidemiológica realizadas. Um total de 133 amostras de soro foram analisadas em Mangue Seco e 81 em Cacha Pregos. Os resultados mostraram que tanto Mangue Seco (63,4%) quanto Cacha Pregos (88,9%) apresentaram animais reativos para o NDV. Os resultados da reação em cadeia da polimerase em tempo real (RT-PCR) e das análises de isolamento viral foram negativos, comprovando que as aves domésticas não estavam eliminando o vírus no momento da coleta das amostras. O alto percentual de animais reativos pelo teste ELISA indireto em ambas as unidades epidemiológicas estudadas sugere a presença de cepa lentogênica circulante de NDV, uma vez que não houve registro de óbito e as aves não apresentavam sintomas característicos da doença.(AU)

Effect of Dietary Inclusion of Sodium Bicarbonate on Digestibility of Nutrients and Immune Response in Caged Layers During the Summer

The aim of this project was to investigate the effect of dietary inclusion of sodium bicarbonate (NaHCO3) on nutrient digestibility and immune response of caged layers during summer when the temperature exceeds 40 C. For immune response trial, White Leghorn layers (n=160; 24 weeks old) were purchased from a poultry farm and were divided into five treatment/diets groups (4 replicate/treatment). Diet A, was without NaHCO3 and served as control whereas, diets B, C, D, and E contained 0.5, 1.0, 1.5 and 2.0% NaHCO3, respectively. All these birds were vaccinated against Newcastle disease (ND) virus at the start of the experiment and thereafter with one-month intervals. Blood samples were collected from two birds/replicate at 10 days post vaccination each time to check antibody titer against ND virus. For digestibility trial, fecal samples were collected (6 layers/treatment group) at the start of the 37th week of age for two days, at 3 hours interval. Results revealed that immune response against ND virus 10 days post vaccination after 1st, 2nd and 3rd month was significantly (p 0.05) higher in layer birds fed diets containing NaHCO3. Digestibility of dry matter (DM), crude protein (CP), crude fiber (CF), ether extract (EE) and absorption of minerals were also found to be significantly (p 0.05) higher in groups treated with NaHCO3 and the birds fed diet containing 1% NaHCO3 showed the best results. In general, results revealed that 1% supplementation of NaHCO3 in layers diet have a beneficial impact in terms of immunity and diet digestibility.(AU)

Effect of Dietary Inclusion of Sodium Bicarbonate on Digestibility of Nutrients and Immune Response in Caged Layers During the Summer

The aim of this project was to investigate the effect of dietary inclusion of sodium bicarbonate (NaHCO3) on nutrient digestibility and immune response of caged layers during summer when the temperature exceeds 40 C. For immune response trial, White Leghorn layers (n=160; 24 weeks old) were purchased from a poultry farm and were divided into five treatment/diets groups (4 replicate/treatment). Diet A, was without NaHCO3 and served as control whereas, diets B, C, D, and E contained 0.5, 1.0, 1.5 and 2.0% NaHCO3, respectively. All these birds were vaccinated against Newcastle disease (ND) virus at the start of the experiment and thereafter with one-month intervals. Blood samples were collected from two birds/replicate at 10 days post vaccination each time to check antibody titer against ND virus. For digestibility trial, fecal samples were collected (6 layers/treatment group) at the start of the 37th week of age for two days, at 3 hours interval. Results revealed that immune response against ND virus 10 days post vaccination after 1st, 2nd and 3rd month was significantly (p 0.05) higher in layer birds fed diets containing NaHCO3. Digestibility of dry matter (DM), crude protein (CP), crude fiber (CF), ether extract (EE) and absorption of minerals were also found to be significantly (p 0.05) higher in groups treated with NaHCO3 and the birds fed diet containing 1% NaHCO3 showed the best results. In general, results revealed that 1% supplementation of NaHCO3 in layers diet have a beneficial impact in terms of immunity and diet digestibility.

Phylogenetic and pathotypic characterization of a Newcastle disease virus strain isolated from ducks and pigeons in Hubei, China

Newcastle disease is a highly contagious disease responsible for major outbreaks and considerable economic losses in the poultry industry in China. There is still little information available regarding gene characterization of the NDV, especially in ducks and pigeons. Therefore, the aim of this study was to investigate NDV isolated from ducks and pigeons in Hubei, China. In this study, three NDVs from ducks and pigeons were isolated between 2013 and 2015.The fusion protein (F) gene of the NDV isolates was sequenced and phylogenetically analyzed. The clinical signs and gross histopathological lesions were examined. Phylogenetic analysis of these strains indicated that all the sequences are classified as genotype II. The isolates shared a 112 G-R-Q-G-R-L 117motif at the F protein cleavage site, indicating that these three isolates strains are lentogenic. Necropsy and histopathology showed the typical pathological changes. It was concluded that commercial ducks and pigeons in Hubei province carry lentogenic NDV strains with regular genetic divergence, indicating that these species may act as the main reservoirs of NDV in poultry. Therefore, strategies and surveillance should be undertaken to reduce the risk of ND outbreaks.(AU)

Phylogenetic and pathotypic characterization of a Newcastle disease virus strain isolated from ducks and pigeons in Hubei, China

Newcastle disease is a highly contagious disease responsible for major outbreaks and considerable economic losses in the poultry industry in China. There is still little information available regarding gene characterization of the NDV, especially in ducks and pigeons. Therefore, the aim of this study was to investigate NDV isolated from ducks and pigeons in Hubei, China. In this study, three NDVs from ducks and pigeons were isolated between 2013 and 2015.The fusion protein (F) gene of the NDV isolates was sequenced and phylogenetically analyzed. The clinical signs and gross histopathological lesions were examined. Phylogenetic analysis of these strains indicated that all the sequences are classified as genotype II. The isolates shared a 112 G-R-Q-G-R-L 117motif at the F protein cleavage site, indicating that these three isolates strains are lentogenic. Necropsy and histopathology showed the typical pathological changes. It was concluded that commercial ducks and pigeons in Hubei province carry lentogenic NDV strains with regular genetic divergence, indicating that these species may act as the main reservoirs of NDV in poultry. Therefore, strategies and surveillance should be undertaken to reduce the risk of ND outbreaks.

Phylogenetic and pathotypic characterization of newcastle disease virus in Tibetan chickens, China

Chickens are considered to be potential reservoirs of Newcastle disease virus (NDV). In this study, six Newcastle disease virus strains were isolated and characterized in Tibetan chickens. The HN gene was sequenced, and phylogenetic relationship to reference strains was studied. The phylogenetic analysis demonstrated that these six isolated strains were closely related to NDV isolates of the reference strains GQ245823, KT002186, KU527561, KJ563939, AY225110, EU305607, KM056357, Y18898, GQ245832, AF077761 and lasota strain. Among them, EU305607, KJ563939 and KM056357 were isolated from India, while lasota strain came from attenuated vaccine widely used in China. Then, mean death time (MDT) and intracerebral pathogenicity index (ICPI) were used to estimate the pathogenicity of the isolates. Pathogenicity experiment showed HNH1 and HN17 to be virulent. Our results indicated that genetically diverse viruses circulate in Tibetan chickens, and based upon the phlogeographic analysis, we estimated the origin of ancestral viruses of the isolates and its sister strains located in India and China (lasota strain). It indicates the importance of continuous surveillance to enhance current understanding of the genetic evolution of the NDV strains.(AU)

Phylogenetic and pathotypic characterization of newcastle disease virus in Tibetan chickens, China

Chickens are considered to be potential reservoirs of Newcastle disease virus (NDV). In this study, six Newcastle disease virus strains were isolated and characterized in Tibetan chickens. The HN gene was sequenced, and phylogenetic relationship to reference strains was studied. The phylogenetic analysis demonstrated that these six isolated strains were closely related to NDV isolates of the reference strains GQ245823, KT002186, KU527561, KJ563939, AY225110, EU305607, KM056357, Y18898, GQ245832, AF077761 and lasota strain. Among them, EU305607, KJ563939 and KM056357 were isolated from India, while lasota strain came from attenuated vaccine widely used in China. Then, mean death time (MDT) and intracerebral pathogenicity index (ICPI) were used to estimate the pathogenicity of the isolates. Pathogenicity experiment showed HNH1 and HN17 to be virulent. Our results indicated that genetically diverse viruses circulate in Tibetan chickens, and based upon the phlogeographic analysis, we estimated the origin of ancestral viruses of the isolates and its sister strains located in India and China (lasota strain). It indicates the importance of continuous surveillance to enhance current understanding of the genetic evolution of the NDV strains.(AU)

Pathological and molecular findings of avian avulavirus type 1 outbreak in pigeons (Columba livia) of southern Brazil / Achados patológicos e moleculares da infecção por avulavirus aviário tipo 1 em pombos (Columba livia) do sul do Brasil

The Newcastle disease, caused by avian avulavirus type 1 strains (APMV-1) is an important avian disease involved into high rates of mortality and economic losses. Several outbreaks have been reported over the last 30 years in Columbiformes in different parts of the world, caused by a adapted variant strain of AAvV-1, called pigeon paramyxovirus type 1 (PPMV-1). A high mortality associated with an outbreak was analyzed in free-living pigeons (Columba livia) in a public square in Porto Alegre in Southern Brazil. A total of 24 pigeons moribund or freshly dead, within five weeks interval were submitted to necropsy, histopathological, immunohistochemical (anti-Newcastle), and RT-PCR followed by sequencing of the amplification products analysis. They presented neurological signs, non-suppurative encephalitis and encephalomyelitis, and mononuclear inflammatory infiltrate in different organs. Immunohistochemical analysis in nine pigeons tissue showed that anti-Newcastle was expressed in brain, kidney, liver and pancreas. The RT-PCR test for the M protein of Newcastle disease virus was positive in six pigeons. The differential diagnosis of Influenza, West Nile, Mycoplasma gallisepticum and Mycoplasma synoviae in all pigeons presented negative results. The sequence of amino acids in the cleavage site region of the F protein was 112RRQKRF117 classifying the strain as virulent. The phylogenetic analysis classified this virus strain into Class II and VI genotype.(AU)

A doença de Newcastle, causada por cepas de avulavirus aviário tipo 1 (AAvV-1), é uma doença de aves importante por causar altos índices de mortalidade e perdas econômicas. Vários surtos têm sido relatados ao longo de 30 anos em aves da ordem Columbiformes, em diferentes partes do mundo, causados por uma cepa variante específica de AAvV-1, denominada Pigeon paramyxovirus tipo 1 (PPMV-1). Foi analisado um surto de mortalidade em pombos domésticos (Columba livia), provenientes de uma praça pública em Porto Alegre, no Sul do Brasil. Vinte e quatro aves moribundas ou mortas foram submetidas, no intervalo de cinco semanas, ao exame de necropsia, exame histopatológico, imuno-histoquímico anti-Newcastle, RT-PCR e sequenciamento. Apresentaram sinais neurológicos, encefalite e encefalomielite não supurativas, além de infiltrado inflamatório mononuclear em diversos órgãos. Nove aves demonstraram exame imuno-histoquímico positivo em órgãos como cérebro, rim, fígado e pâncreas. Seis aves foram positivas no exame de RT-PCR para a proteína M do vírus da Doença de Newcastle. Nos exames de diagnósticos diferenciais de Influenza, West Nile, Mycoplasma gallisepticum e Mycoplasma synoviae, todas as aves testadas foram negativas. A sequência dos aminoácidos na região do sítio de clivagem da proteína foi 112RRQKRF117, classificando a cepa como virulenta. De acordo com a análise filogenética o vírus identificado foi classificado como pertencente à classe II e ao genótipo VI.(AU)

Pathological and molecular findings of avian avulavirus type 1 outbreak in pigeons (Columba livia) of southern Brazil / Achados patológicos e moleculares da infecção por avulavirus aviário tipo 1 em pombos (Columba livia) do sul do Brasil

The Newcastle disease, caused by avian avulavirus type 1 strains (APMV-1) is an important avian disease involved into high rates of mortality and economic losses. Several outbreaks have been reported over the last 30 years in Columbiformes in different parts of the world, caused by a adapted variant strain of AAvV-1, called pigeon paramyxovirus type 1 (PPMV-1). A high mortality associated with an outbreak was analyzed in free-living pigeons (Columba livia) in a public square in Porto Alegre in Southern Brazil. A total of 24 pigeons moribund or freshly dead, within five weeks interval were submitted to necropsy, histopathological, immunohistochemical (anti-Newcastle), and RT-PCR followed by sequencing of the amplification products analysis. They presented neurological signs, non-suppurative encephalitis and encephalomyelitis, and mononuclear inflammatory infiltrate in different organs. Immunohistochemical analysis in nine pigeons tissue showed that anti-Newcastle was expressed in brain, kidney, liver and pancreas. The RT-PCR test for the M protein of Newcastle disease virus was positive in six pigeons. The differential diagnosis of Influenza, West Nile, Mycoplasma gallisepticum and Mycoplasma synoviae in all pigeons presented negative results. The sequence of amino acids in the cleavage site region of the F protein was 112RRQKRF117 classifying the strain as virulent. The phylogenetic analysis classified this virus strain into Class II and VI genotype.(AU)

A doença de Newcastle, causada por cepas de avulavirus aviário tipo 1 (AAvV-1), é uma doença de aves importante por causar altos índices de mortalidade e perdas econômicas. Vários surtos têm sido relatados ao longo de 30 anos em aves da ordem Columbiformes, em diferentes partes do mundo, causados por uma cepa variante específica de AAvV-1, denominada Pigeon paramyxovirus tipo 1 (PPMV-1). Foi analisado um surto de mortalidade em pombos domésticos (Columba livia), provenientes de uma praça pública em Porto Alegre, no Sul do Brasil. Vinte e quatro aves moribundas ou mortas foram submetidas, no intervalo de cinco semanas, ao exame de necropsia, exame histopatológico, imuno-histoquímico anti-Newcastle, RT-PCR e sequenciamento. Apresentaram sinais neurológicos, encefalite e encefalomielite não supurativas, além de infiltrado inflamatório mononuclear em diversos órgãos. Nove aves demonstraram exame imuno-histoquímico positivo em órgãos como cérebro, rim, fígado e pâncreas. Seis aves foram positivas no exame de RT-PCR para a proteína M do vírus da Doença de Newcastle. Nos exames de diagnósticos diferenciais de Influenza, West Nile, Mycoplasma gallisepticum e Mycoplasma synoviae, todas as aves testadas foram negativas. A sequência dos aminoácidos na região do sítio de clivagem da proteína foi 112RRQKRF117, classificando a cepa como virulenta. De acordo com a análise filogenética o vírus identificado foi classificado como pertencente à classe II e ao genótipo VI.(AU)

Evaluation of the Viral Interference between Lentogenic Newcastle Disease Virus (Lasota) and Avian Influenza Virus (H9N2) using Real-Time Reverse Transcription Polymerase Chain Reaction in SPF Chicken

Lentogenic Newcastle disease virus (lNDV) such as Lasota strain and low pathogenicity avian influenza such as H9N2 virus are two of the most economically important viruses affecting poultry worldwide, and little attention in recent years has been paid to simultaneous infections in chickens with these two viruses for the reason that co-infection do occur but are not easily detected. In the present study, chickens were inoculated with lNDV (Lasota) and LPAIV (A/chicken/Tehran/ZMT-173/99(H9N2)) simultaneously or sequentially three days apart. Oropharyngeal and cloacal swabs were collected from chickens from 1 to 14 days after inoculation. RRT-PCR for AIV and NDV detection was performed. The rate of viral shedding was measured within 14 days. No clinical symptoms were observed during the experiment however the pattern of virus shed was different with co-infection, thus comparing the results obtained from viral shedding showed that AIV is a much stronger agent than NDV in the occurrence of viral interference. This is due to the fact that in simultaneous inoculation, AIV replication delayed and reduced NDV replication, while replication of Lasota in simultaneous or pre-inoculated inoculation could not significantly disrupt H9N2 virus replication. These findings indicate that the infection with one virus can interfere with the replication of another, modifying the pathogenesis of the viruses. So, infection of the host with both viral agents simultaneously causes higher shedding of LPAIV than lNDV in OP and CL areas. In conclusion, co-infection with LPAVI in chickens did not impact clinical signs but affected the replication dynamics of these viruses.(AU)