A、B、J亚群禽白血病病毒混合感染的鉴定及gp85基因序列分析OACSTPCD

[Objective]The aim of this study was to investigate the mixed infection of Avian leukosis virus(ALV)subgroups and the genetic variation of gp85 gene in Hubei province,and provide reference for further study on the epidemiology of mixed infection of ALV.[Method]A dead chicken suspected of ALV infection from Yichang,Hubei province was subjected to pathological autopsy,and the diseased tissue was asepsis collected and inoculated with DF-1 cells for virus isolation.The subgroups were identified by PCR,ELISA and indirect immunofluorescence assay(IFA),and the similarity and variation of gp85 gene of isolates were further analyzed.[Result]The autopsy results showed that the kidneys and spleen of the dead chickens were swollen,with lung bleeding,and gray white tumor nodules were visible on the surface.After the tissue homogenates were inoculated into DF-1 cells,the cell supernatant was positive for P27 antigen by ELISA,and specific green fluorescence was detected in the infected cells by IFA.The specific bands of subgroups A(692 bp),B(847 bp)and J(545 bp)could be amplified simultaneously by PCR.The results of identification showed that the natural mixed strains of ALV of subgroups A,B and J were isolated from the dead chicken,which were named as HBYC2022-A,HBYC2022-B and HBYC2022-J,respectively.HBYC2022-A shared 99.6％nucleotide identity with JS-A1201 strain in Jiangsu province.HBYC2022-B shared 99.7％similarity with JS-B1204 strain.HBYC2022-J shared 100％identity with Heilongjiang strain PK19FA01,Guangxi strain GX20YL12 J and Anhui strain AHaq02.In addition,there were no special point mutations in the amino acid sequences of the gp85 highly mutated regions(hr1 and hr2).[Conclusion]There was mixed infection of different ALV subgroups A,B,and J in chicken flocks,suggesting that the domestic poultry farms should be vigilant and the epidemiological investigation of ALV subgroups should be strengthened.