• Korean Journal of Veterinary Research
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• v.51 no.3
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• pp.209-216
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• 2011

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 $50^{\circ}C$ for 30 min, but labile to 100% ethanol, heat at $52{\sim}60^{\circ}C$ for 30 min, 1 M $MgCl_2$ at $50^{\circ}C$ 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.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2005.11a
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• pp.80-81
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• 2005

The occurrence of HHS was confirmed for the first time in Korea from chickens submitted for diagnosis to our laboratory from broiler and baeksemi farms. Clinical signs included depression, inappetence, ruffled feathers and a increase in mortality. At necropsy, severe hydropericardium and hepatic necrosis was founded characteristically and the most remarkable microscopic changes were seen in the liver. These included basophilic intranuclear inclusion bodies in the hepatocytes, massive hemorrhages and necrosis in the liver parenchyma. We could also identify fowl adeno-virus(FAV) by polymerase chain reaction(PCR) and electro-microscopic confirmation. Abbreviation: HHS=hydropericardium hepatitis syndrome, EM=electron microscopy, FAV=fowl adenovirus, PCR=polymerase chain reaction.

• Korean Journal of Poultry Science
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• v.41 no.1
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• pp.15-20
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• 2014

Fowl adenovirus (FAV) is an important cause of several diseases, which result in considerable economic losses to the poultry farm. An outer capsid protein of FAV, fiber 2 is essential for virus growth, assembly or spread. This study was performed to produce about 22 kDa of recombinant fiber 2 protein and to immunize in laying hens to acquire the specific IgY antibody against the recombinant fiber 2. Laying hens were immunized with the recombinant fiber 2 intramuscularly in the breast muscle by injection 4 times at intervals of three weeks. At 12 weeks, serum- and egg yolk-antibody titers of hens against fiber 2 were increased up to 430,000 and 414,000, respectively. The recombinant fiber 2 could be recognized be the anti-His monoclonal antibody. Anti-fiber 2-IgY antibody could recognize the fiber 2 specifically in western blot analysis. These results suggested that the recombinant fiber 2 antigen could be used as an immunogen to elicit IgY antibody against fiber 2 and the anti-fiber 2-IgY could neutralize fowl adenovirus fiber 2 effectively.

• Korean Journal of Veterinary Service
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• v.34 no.2
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• pp.139-148
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• 2011

Avian reovirus (ARV) and fowl adenovirus (FAdV) were evaluated for pathogenicity in specific pathogen free (SPF) chickens. ARV was isolated from the broilers with history of malabsorption syndrome (MAS). FAdV was isolated from the layer breeders with inclusion body hepatitis and hydropericardium syndrome. Total 6 inoculated groups including 1 un-inoculated group were organized and inoculated with the ARV and/or FAdV by oral route. The minimal pathological lesions and lower viral gene detection rates were present in the ARV inoculated groups compared to those of FAdV or ARV/FAdV inoculated groups. Common gross lesions in the ARV inoculated group were distended intestine with foamy contents and in the FAdV group there were foamy cecal contents and hydropericardium among the evaluation methods such as gross and histological lesion, viral gene detection, body weight and serum chemistry, histopathological lesion score was reliable especially in the liver lesions such as hepatic necrosis and lymphocytic infiltration. However, we did not success to evaluate the synergetic effect of mixed infection of ARV and FAdV in this study. Therefore, we need further study to reproduce malabsorption syndrome of ARV infection using different viral agent such as rotavirus and using different dose of virus.

• Journal of Veterinary Science
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• v.22 no.4
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• pp.42.1-42.16
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• 2021

Background: Inclusion body hepatitis (IBH) is an economically important viral disease primarily affecting broiler and breeder chickens. All 12 serotypes of fowl adenovirus (FAdV) can cause IBH. Objectives: To characterize FAdV isolates based on phylogenetic analysis, and to study the pathogenicity of FAdV-8b in specific-pathogen-free (SPF) chickens following virus inoculation via oral and intramuscular (IM) routes. Methods: Suspected organ samples were subjected to virus isolation and polymerase chain reaction (PCR) for FAdV detection. Hexon gene sequencing and phylogenetic analysis were performed on FAdV-positive samples for serotype identification. One FAdV-8b isolate, UPM/FAdV/420/2017, was selected for fiber gene characterization and pathogenicity study and was inoculated in SPF chickens via oral and IM routes. Results: The hexon gene phylogenetic analysis revealed that all isolates belonged to FAdV-8b. The fiber gene-based phylogenetic analysis of isolate UPM/FAdV/420/2017 supported the grouping of that isolate into FAdV species E. Pathogenicity study revealed that, chickens infected with UPM/FAdV/420/2017 via the IM route had higher clinical score values, higher percent mortality, higher degree of the liver lesions, higher antibody response (p < 0.05), and higher virus shedding amounts (p < 0.05) than those infected via the oral route. The highest virus copy numbers were detected in liver and gizzard. Conclusions: FAdV-8b is the dominant FAdV serotype in Malaysia, and pathogenicity study of the FAdV-8b isolate UPM/FAdV/420/2017 indicated its ability to induce IBH in young SPF chickens when infected via oral or IM routes.

• Journal of Veterinary Science
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• v.19 no.6
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• pp.759-770
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• 2018

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 $10^{8.7}TCID_{50}/mL$ ($TCID_{50}$, 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.

• Korean Journal of Veterinary Service
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• v.30 no.3
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• pp.313-319
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• 2007

Avian adenoviruses are diverse group of pathogens and recently hydropericardium hepatitis syndrome (HHS) Is an important, emerged disease of poultry. Particularly 2-3 weeks old age broilers increased mortality ranging from 20-30% and brown native chicken 3-7 weeks sudden onset with mortality 20-50%, typically development secondary infection. The infection chicken shows liver enlarged, pale and straw- colored fluid is present in the sac surrounding the heart. Histopathological positive samples have necrotic foci and basophilic intranuclear inclusion bodies in the hepatocytes and polymerase chain reaction (PCR) was useful for detect the fowl adenovirus (FAV) associated with HHS.

• Korean Journal of Veterinary Service
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• v.41 no.1
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• pp.21-27
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• 2018

Fowl adenovirus (FAdV) and chicken anemia virus (CAV) have gained much importance as an immunosuppressive and economically important emerging pathogen of poultry. This study was carried out to investigate the prevalence of FAdV and CAV infection in chickens. The groups were divided into Korean native chickens, broiler, layer hens and broiler breeder and set up groups according to age. As results, 12.5% of the native chicken, 2.5% of broiler and 6.7% of layer chicken were positive, respectively by PCR for FAdV. Serological test showed that 84.8%, 79.0%, 97.7% and 96.1% of chickens were positive for antibody to FAdV in native chickens, broiler, layer hens and broiler breeder. The prevalence of CAV infection were 20.0%, 7.5%, 16.7% and 10.0%, based on CAV gene detection by PCR. In serological test of CAV, 40.6%, 35.9%, 84.8% and 73.9% of chickens were positive in that groups.

• Korean Journal of Poultry Science
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• v.37 no.3
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• pp.255-263
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• 2010

Inclusion body hepatitis-hydropericardium syndrome (IBH-HPS) is an acute viral disease usually found in broilers aged from 3 to 5 weeks and causes up to 75% mortality. Among the 12 serotypes of fowl adenovirus group 1, serotype-4 (FAdV-4) was identified as a primary agent of IBH-HPS and was usually isolated in IBH-HPS cases in Korea since 2007. To prevent these IBH-HPS outbreaks in Korea, we developed the FAdV-4 inactivated vaccine using Korean isolate (ADL070244) and evaluated the efficacy of this vaccine. For the efficacy test, 2-week-old specific-pathogen-free (SPF) chickens intramuscularly inoculated with 1 or 2 dose of inactivated vaccine were used and challenged with FAdV-4 through either intramuscular or oral route at 2 weeks after vaccination. The vaccine induced good seroconversion which was confirmed by agar gel precipitation (AGP) test. In addition, the vaccine could decrease the FAdV-4 detection rate and histological lesion severity such as lymphocyte infiltration and necrosis in the liver comparing with those of non-vaccination group. Based on the current results, the developed FAdV-4 inactivated vaccine in this study was effective in the terms of reduction of virus detection rate and histological lesions severity. However, it was difficult to confirm the efficacy of the vaccine clearly because of no mortality and clinical signs in the non-vaccinated group after challenge. Therefore, we need further study to develop a standard challenged model system which could clearly evaluate the efficacy of the vaccines for FAdV-4.

• Korean Journal of Poultry Science
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• v.37 no.3
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• pp.237-245
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• 2010

A survey of transovarially transmitted diseases, including salmonellosis [(pullorum disease; PD)/(fowl typhoid; FT)], mycoplasmosis, avian infectious anemia (CIA), and fowl adenovirus infection was conducted in the breeder chickens from August to December in 2009. The numbers of flocks sampled out were: Grand Parents Stock (GPS), 45; Parents Stock (PS) 1,018, Baeksemi breeder (BSB) 54. The seroprevalence of salmonellosis (PD/FT) were 0% (GPS), 3.2% (PS), and 3% (BSB), respectively. A total of 983 chicken farms were affected with FT outbreaks between 2000 and 2008. The incidence of FT in commercial broilers, Baeksemi, commercial layers, native chickens, and broiler breeders was 44.3%, 26.2%, 15.7%, 12.6% and 1.08%, respectively. Of the affected broilers, over 90% birds were under 2 weeks of age, indicating it was possible that they were infected with S. gallinarum via vertical transmission. The sero-positive flocks against Mycoplasma gallisepticum (MG) were 71.1% (GPS), 88.7% (PS), 88.7% (BSB), while the rates of positive flocks against Mycoplasma synoviae (MS) were 86.0% (GPS), 77.0% (PS), and 98.0% (BSB). In GP and parent farms, the detection rates on specific genes of CIA virus were 19/45 (42.2%), and 169/1039 (18.0%), respectively, whereas the seroprevalence of CIA were 86.0% in GPS and 93.7% in PS flocks. In addition, positive flocks of fowl adenoviruses were 4.4% (GPS), 2.7% (PS) and 9.35% (BSB), respectively. As the results, avian mycoplasmosis and CIA have been more prevailing in chicken breeder than avian salmonellosis and fowl adenovirus infection in Korea.