Pathogenicity of an FAdV-4 isolate to chickens and its genomic analysis / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Fowl adenovirus serotype 4 (FAdV-4) strain SD1511 was isolated from chickens with severe inclusion body hepatitis and hydropericardium syndrome in Shandong Province, China. The isolate was cultured in primary chicken embryo kidney cells. A study of pathogenicity indicated that SD1511 readily infected 7–35-d-old chickens by intramuscular injection and intranasal and oral routes, causing 50%–100% mortality. The 35-d-old chickens suffered more severe infection than 7- and 21-d-old chickens with mortality highest in the intramuscular injection group. The serum from surviving chickens showed potent viral neutralizing capability. The complete genome of SD1511 was sequenced and analyzed. The strain was found to belong to the FAdV-4 cluster with more than 99% identity with the virulent FAdV-4 strains isolated in China in recent years except for some distinct variations, including deletions of open reading frame 27 (ORF27), ORF48, and part of ORF19. Our findings suggest that SD1511 might be used as a prototype strain for the study of pathogenesis and vaccine development.

Pathogenicity of an FAdV-4 isolate to chickens and its genomic analysis / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Fowl adenovirus serotype 4 (FAdV-4) strain SD1511 was isolated from chickens with severe inclusion body hepatitis and hydropericardium syndrome in Shandong Province, China. The isolate was cultured in primary chicken embryo kidney cells. A study of pathogenicity indicated that SD1511 readily infected 7-35-d-old chickens by intramuscular injection and intranasal and oral routes, causing 50%-100% mortality. The 35-d-old chickens suffered more severe infection than 7- and 21-d-old chickens with mortality highest in the intramuscular injection group. The serum from surviving chickens showed potent viral neutralizing capability. The complete genome of SD1511 was sequenced and analyzed. The strain was found to belong to the FAdV-4 cluster with more than 99% identity with the virulent FAdV-4 strains isolated in China in recent years except for some distinct variations, including deletions of open reading frame 27 (ORF27), ORF48, and part of ORF19. Our findings suggest that SD1511 might be used as a prototype strain for the study of pathogenesis and vaccine development.

Hexon and fiber gene changes in an attenuated fowl adenovirus isolate from Malaysia in embryonated chicken eggs and its infectivity in chickens

Fowl adenovirus (FAdV) is distributed worldwide and causes economic losses in the poultry industry. The objectives of this study were to determine the hexon and fiber gene changes in an attenuated FAdV isolate from Malaysia in specific pathogen-free chicken embryonated eggs (SPF CEE) and its infectivity in commercial broiler chickens. SPF CEE were inoculated with 0.1 mL FAdV inoculum via the chorioallantoic membrane (CAM) for 20 consecutive passages. The isolate at passage 20 (E20), with a virus titer of 10(8.7)TCID₅₀/mL (TCID₅₀, 50% tissue culture infective dose), was inoculated (0.5 mL) into one-day-old commercial broiler chicks either via oral or intraperitoneal routes. The study demonstrated that 100% embryonic mortality was recorded from E2 to E20 with a delayed pattern at E17 onwards. The lesions were confined to the liver and CAM. Substitutions of amino acids in the L1 loop of hexon at positions 49 and 66, and in the knob of fiber at positions 318 and 322 were recorded in the E20 isolate. The isolate belongs to serotype 8b and is non-pathogenic to broiler chickens, but it is able to induce a FAdV antibody titer. It appears that molecular changes in the L1 loop of hexon and the knob of fiber are markers for FAdV infectivity.

Fowl adenovirus Group I as a causal agent of inclusion body hepatitis/hydropericardium syndrome (IBH/HPS) outbreak in brazilian broiler flocks / Adenovirus aviário Ggrupo I como um agente causal da síndrome da hepatite por corpúsculo de inclusão/hidropericárdio (IBH/HPS) em lotes de frangos de corte

Commercial broiler flocks from a farm located in the State of São Paulo, Brazil, presented diarrhea, depression, increased mortality and poor weight gain. Upon post-mortem examination, classical signs of Inclusion Body Hepatitis/Hydropericardium Syndrome (IBH/HPS) were observed, including enlarged pale yellow-colored livers and straw-colored liquid in the pericardial sac. In addition, gross lesions were also observed in the kidneys, pancreas, thymus, intestines and gallbladder. Samples of these organs were analyzed by PCR for the detection of the hexon gene of the Fowl Adenovirus (FAdVs) Group I. The results were positive for both flocks (A and B) assayed by PCR. The macroscopic lesions associated with the detection of FAdV Group I by PCR in several of these affected organs allowed for the identification of IBH/HPS. In fact, this is the first report in Brazil of IBH/HPS in broilers, which identifies FAdVs group I as a causal agent of the disease. These findings may contribute to the worldwide epidemiology of the adenovirus-mediated hepatitis/hydropericardium syndrome...

Lotes comerciais de frangos de uma granja localizada no Estado de São Paulo, Brasil, apresentavam diarreia, depressão, aumento de mortalidade e baixo ganho de peso. Após o exame post-mortem, sinais clássicos da síndrome de hepatite por corpúsculo de inclusão/hidropericárdio (IBH/HPS) foram observados incluindo hepatomegalia com aspecto amarelado pálido e líquido de coloração amarelo palha no saco pericárdio. Além disso, as alterações macroscópicas foram também observadas nos rins, pâncreas, timo, intestinos e vesícula biliar. Amostras destes órgãos foram analisadas pela técnica de PCR para detectar o adenovírus aviário do grupo I através do gene Hexon. Os resultados foram positivos para ambos os lotes (A e B) utilizando-se a técnica de PCR. As lesões macroscópicas associadas à detecção do adenovírus aviário do grupo I pela técnica de PCR em vários destes órgãos acometidos permitiu a identificação da síndrome de hepatite/hidropericárdio em frangos no Brasil. Ao nosso conhecimento, este é a primeira descrição da síndrome de hepatite/hidropericárdio causado por adenovírus aviário do grupo I, no Brasil. Estes achados podem contribuir com a epidemiologia mundial do adenovírus mediando a síndrome de hepatite/hidropericárdio...

Regulation of T lymphocyte subpopulations in specific pathogen free chickens following experimental fowl adenovirus Ⅷ infection

Two-day-old specific pathogen-free (SPF) chickens were divided into two groups. Group I was inoculated orally with fowl adenovirus VIII (FAV-VIII). Group II served as a negative control. Chickens were investigated at various days post-inoculation (dpi) by flow cytometric analysis for changes in T lymphocyte subpopulations in immune system and blood. In the thymus, CD3+ T lymphocytes were increased at 25 dpi, with significant increases in the FAV infected noted at 1, 12, 20dpi (p<0.05). This was accompanied by a corresponding increase of CD4+ and CD8+ T lymphocytes. In the spleen, CD3+ and CD4+ T lymphocytes were increased significantly at 30 dpi (p<0.01) whereas CD8+ and TCR γ δ+ T lymphocytes were decreased at 1 (p<0.05), 30 dpi (p<0.01). An increase of CD3+, CD4+ and CD8+ T lymphocytes was noticed in peripheral blood, and accompanied by a decrease of TCR γ δ+ T lymphocytes. These results demonstrated that infection with FAV-VIII causes significant fluctuations in T lymphocyte subpopulations in thymus, blood and spleen. It can be concluded that an infection with FAV-VIII has profound effects on the immune system, especially on cell mediated immune competency.

Isolation and characterization of fowl adenovirus serotype 4 from chickens with hydropericardium syndrome in Korea / 대한수의학회지

Four strains of fowl adenovirus (FAdV) were isolated from 4 flocks of broiler or layer chickens affected by hydropericardium syndrome in Korea. These FAdVs were classified as serotype 4 by restriction fragment length polymorphism patterns of hexon genes and whole genomes. The virus exhibited cytopathic effects consisting of rounding, ballooning and clustering in primary chicken embryo liver cell cultures. In transmission electron microscopy, virus particles in hexagonal shape aggregated exclusively in the nuclei of hepatocytes of the chickens as the typical appearances in adenovirus infections. Buoyant density of the virus in cesium chloride (CsCl) was 1.34 g/mL. The virus was stable to chloroform, ether, 50~70% ethanol, acidic condition at pH 3, 0.25% trypsin (1 : 250), heat at 50degrees C for 30 min, but labile to 100% ethanol, heat at 52~60degrees C for 30 min, 1 M MgCl2 at 50degrees C for 1 h, 1 : 2,000 formalin (37%). All of the physicochemical properties pertained to the characteristics of adenoviruses. Eight viral polypeptides were determined in CsCl-purified virus by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.