Serological and phylogenetic analysis indicating prevalence of fowl adenovirus in China
Fowl adenoviruses (FAdVs), which belong to the genus  Aviadenovirus  in the Adenoviridae family, are grouped into five species named Fowl adenovirus A–E ( FAdV-A to FAdV - E ) and 12 serotypes (1–11, 8a, 8b) based on genome sequencing and virus neutralisation, respectively. FAdVs are responsible for a wide range of clinical signs, including hydropericardium-hepatitis syndrome (HHS), inclusion body hepatitis (IBH) and gizzard erosion (GE).1 HHS is primarily caused by the FAdV-4 serotype and causes more than 30 per cent mortality.2 3 IBH is related to the multiserotype of FAdVs and leads to 10–30 per cent mortality in chickens. Some FAdV-1 strains are responsible for GE.1 3

Cases of IBH or HHS have been increasing rapidly, resulting in great economic losses worldwide.3–8 In the present study, we determined the prevalence of FAdV infections in chicken flocks in China by serological analysis and characterised the genotypic distribution among the FAdV strains previously reported in China in GenBank database by phylogenetic analysis. Our findings could provide implications for a promising control measure and vaccination strategy for FAdV infection in the poultry industry.

To evaluate the prevalence of FAdV infections in China, a total of 4544 serum samples were collected from 119 different non-vaccinated chicken flocks in 2014–2016. These samples were localised in 13 provinces or cities in …
Two novel monoclonal antibodies against fiber-1 protein of FAdV-4 and their application in detection of FAdV-4/10
BackgroundRecently, serotype 4 fowl adenovirus (FAdV-4) has spread widely and caused huge economic loss to poultry industry. However, little is known about the molecular pathogenesis of FAdV-4. Fiber protein is thought to be vital for its infection and pathogenesis.ResultsTwo novel monoclonal antibodies (mAbs) targeting the fiber-1 protein of FAdV-4 were generated, designated as mAb 3B5 and 6H9 respectively. Indirect immunofluorescence assay (IFA) showed that both mAbs only reacted with the FAdV-4 and FAdV-10, not with other serotypes including FAdV-1, FAdV-5, FAdV-6, FAdV-7, FAdV-8 and FAdV-9 tested. Although both mAbs did not recognize the linear epitopes, they could efficiently immunoprecipitate the fiber-1 protein in LMH cells either infected with FAdV-4 or transfected with pcDNA3.1-Fiber-1. Moreover, mAb 3B5 as a capture antibody and HRP-conjugated mAb 6H9 as a detection antibody, a novel sandwich ELISA for efficient detection of FAdV-4 was generated. The limit of detection of the ELISA could reach to 1000 TCID50/ml of FAdV-4 and the ELISA could be efficiently applied to detect FAdV-4 in the clinical samples.ConclusionThe two mAbs specific targeting fiber-1 generated here would pave the way for further studying on the role of fiber-1 in the infection and pathogenesis of FAdV-4, and the established mAb based sandwich ELISA would provide an efficient diagnostics tool for detection of FAdV-4/10.
Development of an enzyme-linked immunosorbent assay to detect and quantify adenovirus in chicken tissues.
An indirect enzyme-linked immunosorbent assay (ELISA) was developed to detect and quantify avian adenovirus (AAV) in various chicken tissues, including blood. A positive ELISA absorbance value was obtained with suspensions of infected liver tissue that contained less than 100 mean tissue-culture infective doses per gram. A positive correlation was observed between the absorbance values and titer of infectious virus in infected liver tissue. A group-specific antigen common to the 12 serotypes of AAV tested was demonstrated by this ELISA. Because of the high sensitivity and broad-spectrum reactivity, this ELISA could be useful for the study of AAV pathogenesis, for laboratory diagnosis of inclusion body hepatitis irrespective of the serotype of AAV involved, and for screening commercial and specific-pathogen-free flocks for the presence of AAV.