Epidemmiological Investigation Of Three Oncogenic Viruses Between2010and2012in Guangxi And Detection Of The Commercial Mdv Live Vaccines

Avian tumors are commonly caused by Marek’s disease Virus (MDV), avian leucosis virus (ALV) and Reticuloendotheliosis Virus (REV). Epidemiological investigation, necropsy, PCR diagnosis, virsus isolated and histopathology observed from paraffin section of fresh lesion were conducted in16stocks of suspected tumor in Guangxi between2010and2012.PCR results demonstrated that7(43.75%) stocks were infected by MDV simply,3(18.75%) stocks were co-infected by MDV and REV, and3(18.75%) stocks were co-infected by MDV, ALV and REV,2(12.5%) stocks were infected by ALV-J simply,1(6.25%) stock was co-infected by MDV and ALV-D. It proved that the most common pathogen was MDV, and the co-infection of MDV, ALV and REV was also commonly.6strains of MDV-1,5strains of ALV-J and1strains of REV were isolated from these cases by inoculated on the chicken embryo fibroblasts (CEF) which made out of SPF embryo. One strain was the co-infection of MDV-1and ALV-J, one strain was the co-infection of MDV-1, REV and ALV-J. Moreover, one train was suspected ALV-D. Immuno fluorescence assay of the cell culture infected by isolations and virus sequence analysis demonstrated that these strains were vvMDV or vv+MDV, REV and ALV-J. The suspected ALV-D strain needed more sequence to confirm.Lymphocyte infiltration was observed by microscope in paraffin sections of tumor tissue infected by MDV simply; lymphocyte and myelocytomas infiltration was observed in tissue co-infected with MDV and ALV-J. Additionally, pathologic difference between tumor tissue, heart granuloma caused by Salmonella pullorum and liver necrosis was determined in paraffin sections of clinical cases.17commercial MDV-1live vaccines and9SPF embryos were detected for exogenous ALV and REV with PCR. The results demonstrated that no target fragments were amplified, it indicated preliminarily that no exogenous ALV and REV in these samples.