Isolation and serological characterization of the fowl adenoviruses associated with respiratory disease in domestic chicken

Respiratory diseases have great importance in poultry production as they pose a serious threat to the poultry farmers affecting productivity. Several pathogens may cause respiratory symptoms in birds, however fowl adenoviruses (FAdV) have recently emerged as a significant respiratory pathogen. Present study describes isolation and serological characterization of FAdVs from the chickens showing respiratory involvement. Lungs and trachea were collected from dead or moribund birds showing respiratory symptoms and isolation of FAdVs was done in chicken embryo liver (CEL) cells. MGG staining of CEL cells showed the presence of basophilic intranuclear inclusions characteristic to aviadenovirus infection. Various serological tests viz., agar gel immunodiffusion (AGID), counter immune-electrophoresis (CIEP), indirect fluorescent antibody test (IFAT), enzyme linked immunosorbent assay (ELISA), dot-ELISA and micro-serum neutralization test (SNT) were standardized for detection of FAdV isolates in cell culture and tissue samples from natural outbreaks reported from Uttar Pradesh, Uttarakhand and Nepal.