Isolation And Identification Of Subgroup J Of Avian Leukosis Virus And Dynamic Comparison And Analysis Of Proliferation Of The Strain In DF-1Cell With Three Detection Methods

Avian Leukosis (Avian Leukosis, AL), caused by Avian Leukosis virus/sarcoma virusgroup (ALV/RSV), is a variety of benign and malignant tumor diseases of poultry, the mainpathological changes of which is malignant hyperplasia hematopoietic cells. It is one of thefirst viruses that proved to cause tumors. According to the difference of antigenicity of thecapsule membrane proteins related to virus host specificity gp85protein and crossneutralization test, ALV can be divided into10subgroups of A~J, of which only A, B, C, D,E and J can infect chickens.Since ALV-J was found in white feature chickens in Britain in1999, it spread to the poultry industry around the world quickly, and brought huge economiclosses to the poultry industry of the world. Since the first time the ALV-J was separated in1999, there have been a lot of reports about the popular status of ALV-J. The most two widelyepidemic pathogenic exogenous virus infection in commercial flocks are ALV-A and ALV-J,ALV-J has stronger ability of horizontal transmission than other subgroup of exogenous ALVs.In recent years, Because of no effective prevention, control and purifying measures are taken,ALV-J is likely to have been widely exists in various kinds of chicken flocks in our country.In this experiment, we inoculated the vaccinated plasma of suspected ALV infectedchickens from Guangzhou three yellow chicken in DF-1cell, By PCR, its env gene wasamplified, cloned and sequenced. Comparison and analysis of env amino acid sequencesbetween the new virus we isolated and other different subgroups strains of ALV publishedindicated that we have got an J sub-group of leukemia viruses.To compare and evaluate the sensitivity of (FA),(IFA) and (ELISA) on dynamicallydetections, based on which we could analysis and assessed the practicability in theproduction practice, the new strain of avian leukosis virus (ALV) subgroup J was inoculatedinto DF-1cells in three concentrations (1×10~4,1×10~3,1×10~2TCID50separately).Supernatantof the DF-1cell cultures was collected and stored them at-80℃for detection of ELISA aimedat p27antigen in the flowing6days. Detections of FA and IFA were done on the inoculatedDF1cells. The results displayed that the ratios of positive infected cells were highlydramatically conformed to the inoculated concentration at the same days, and IFA is the moresensitivity than FA and ELISA kit on the dynamically detection in the field. But in the production practice, ELISA kit is the simplest method for the ALV-J detection, though it hashigh rate of false positive and false negative. Since IFA detection also needs Fluorescencemicroscope and highly manipulation Skills, we should choose ELISA detection combinedwith IFA detection at the same time, to ensure the accuracy and credibility of experimentalresults in the poultry production practice.