The Isolation And Identification Of Avian Leukosis Virus From The Birds Of P27Positive And Clinical Type Of Haemangioma

Avian leukosis (AL) is collectively called benign and malignant tumors of poultry caused by avian leukosis virus (ALV) and avian sarcoma virus (ASV). It was reported recently that chicken of different provinces in China has been infected by ALV. New cases of AL, such as type lesion and haemagioma, have come to the fore. And skin haemangioma has got an especially high incidence, which cost huge economic losses to the poultry industry of China.The thesis studied thirty-three chickens, whose egg albumens or cloacal swabs were detected as p27antigen-positive by ELISA. Whole blood, serum, plasma, heart, liver, spleen, lung, kidney, pancreas, proventriculus, ovary or testis,oviduct, thymus, bone marrow and skin tumors had been collected from each chicken. First of all diseased tissues were tested directly by PCR and then all the handled materials were inoculated to DF-1cells and were passed successively to their generations. The cell cultures of F1and F2were detected respectively by ways of ELISA and PCR. The purpose is to make a compare with the results of the different detective methods and to select the most suitable material to isolate of ALV. Using the experimental methods above,16chickens which clinically showed clear vascular symptoms were isolated and identified by virus and env gene sequences of ALV-J isolates were examined and analyzed.The research shows as follows:First, of all the16chosen materials15can be isolated from ALV except pancreas. And thus indicates that ALV probably exists in all of the15tissues mentioned-above. Second, of all the three ways, ELISA for egg albumen or cloacal swab, PCR and virus isolation, results of the third, especially the detection results of F2cell cultures, are the most reliable. Third, to the living chickens, serum is the best material to isolate ALV and secondly plasma. But to the dead ones, proventriculus is the best and secondly kidney, heart and ovary. Forth, haemangioma occured among three yellow chickens, black chickens of Lingshan and huangxu chickens, which are popularly called Guangxi local chicken breeds. And the rate of three yellow chicken was the highest, which reaches87.5%. Fifth, chickens which clinically showed clear vascular symptoms can be93.75%(15/16) isolated from ALV-J and6.25%(1/16) from A and J subgroups of ALV. It confirms that A and J subgroups of ALV can cause haemangioma, and it is mainly infected by J subgroup of ALV clinically. What’s more, it is found for the first time that mixed infections of A and J subgroups of ALV were discovered in some chicken infected by haemangioma. Finally, gp85, gp37, E element and U3zone of5isolates of ALV-J from chickens infected by haemangioma show variation, whose degree varies.