MOLECULAR AND BIOLOGICAL CHARACTERIZATION OF FOWL AVIADENOVIRUS ISOLATED FROM COMMERCIAL CHICKEN FARMS

Abstract

Fowl Adenovirus (FAdV) is a virus that causes disease in poultry with characteristics such as inclusionsbody found in organ lesions, especially the liver. The disease causes economic losses, in the form of chickendeaths and immunosuppression effects. Since 2018, outbreaks of FAdV or known as inclusion body hepatitis(IBH) have been reported in broiler farms, in several provinces in Indonesia. This study aims to isolate,and characterize molecularly, and biologically of embryonic chicken eggs and liver cell cultures of chickenembryos. Liver samples, bursa fabricius, and spleen were obtained from 23 commercial chicken farms inIndonesia that were diagnosed with IBH disease from 2018-2020. Molecular detection was carried out bypolymerase chain reaction (PCR) technique, using hexon gene-specific primers. The amplification resultwas positive, then sequencing was performed. Isolation was carried out using embryonic chicken eggs(ECE) specific pathogen free (SPF) and chicken embryo liver (CEL) cell cultures. Detection and molecularcharacterization showed that all FAdV isolated from poultry obtained from cases diagnosed with IBHdisease confirmed as FAdV genotype E, including strain FAdV-8b. Isolation on TAB showed embryonicbleeding lesions and swelling of the liver. Propagation of the FADV isolate using chicken embryo liver cellculture, showed cytopathic lesions that could be observed in the first passage, in the form of swelling androunding of infected cells. IBH disease outbreaks in commercial chickens in this study, confirmed the causeis FAdV genotype E, which is included in serotype 8b. FAdV virus isolated on SPF TAB showed embryonicbleeding lesions and hepatitis. FAdV virus isolated in this study was assessed as pathogenic in SPFchicken embryos.