Detection of avian leukosis virus subgroup J in albumen of commercial and native fowl eggs using RT-PCR in Fars province of Iran

The subgroup J of ALV (ALV-J) has emerged as an important pathogen of meat-type chickens since 1989. This virus is responsible for economic losses due to both mortality and depressed performance in chickens. So, the objective of this study is the detection of ALV-J in the albumen of commercial and native fowl eggs using RT-PCR. Three hundred and seventy egg albumens were randomly selected from different farms of Fars province, Iran. These eggs were obtained from the flocks of two research centers on native fowl production (70 eggs), a broiler grandparent farm (60 eggs), three broiler breeder farms (180 eggs), and a commercial layer flock (60 eggs). RT-PCR was undertaken on isolated RNA from egg samples using a pair of ALV-J specific primers H5/H7 that produced a 545 basepair fragment. RT-PCR analyses detected ALV-J in 15 of 180 (8.33%) samples from three broiler breeders farms, 17 of 70 (24.28%) samples from flocks of two research centers of native fowls production, and none of the samples of commercial layer and broiler grandparent farms. Direct sequencing using primers specific for subgroup ALV-J verified the viral subgroup in the RT-PCR amplification products. This is the first report of the ALV-J in egg albumen in Iran which indicates the necessity to apply eradication programs for ALV-J in the poultry industry and native fowls in Iran