The Prevalent State Of Avian Leukosis In Jilin Province

Avian leukosis(AL)is a kind of tumorigentic infectious disease which is caused by avian leukosis virus(ALV),and it is epidemic in around the world by horizontal and vertical transmissioncan.AL can caused multiple tumor and affected the organism immunity,which finally leading to immune suppression and the death of chicken.These has brought great economic losses on the poultry industry.In order to reduce the harm to the poultry industry produced by the disease,the work for prevention and removal of AL is the primary task.This present study was conducted to investigate the prevalence of AL in Jilin Province by establishing the ALV-J fluorescent quantitative PCR method in order to provide theoretical basis for the prevention and purification of AL.The first part of this study is to establish a fluorescent quantitative PCR method for the detection of subgroup J ALV(ALV-J)which was in the epidemic high in Jilin province.According to ALV-J gene sequence from GeneBank,relevant probes and primers were designed and synthesized.The ALV-J plasmid was preparation and extraction for establishing the standard curve,fluorescent quantitative PCR reaction system and conditions were optimize with specificity,sensitivity and repeatability.These results showed that the established fluorescent quantitative PCR detection method had good specificity,which had no cross reaction with subgroup A/B avian leukosis virus newcastle disease virus(NDV)and avian influenza virus(AIV).Furthermore,this method can detect the virus nucleic acid samples with the concentration of 196 copies/ μL.Its relative sensitivity was higher than that of National Standard(GB/T 26436-2010),and the coefficient of variation of the repeated test is below 1%.On this basis,the method is fitted for the qualitative and quantitative detection of clinical ALV-J.The second part of this study: 2000 serum samples and 2000 cotton swab were collected from ten chicken farms in five cities of Jilin province.ALV-J antigen,ALV-AB,ALV-J antibody and p27 antigen test were assayed by established fluorescent quantitative PCR method and ELISA kit.The results showed that the average positive rate of ALV-AB subtype antibody,the average positive rate of ALV-J subgroup antibody,and the average positive rate of p27 antigen were respectively 7.65%,11.55%,and 14.55% in Jilin province chicken farm.Meanwhile,the results of fluorescent quantitative PCR detection of ALV-J was 12.40%.Established fluorescent quantitative PCR method for the detection ALV-J has good detection accuracy compared to the ELISA method,and the coincidence rate of the two methods reached 88.75%.Furthermore,the detection rate of fluorescent quantitative PCR method was higher than that of ELISA method,itshowed more advantages.Therefore,the investigation results of the epidemic of avian leukosis in Jilin province showed that: the ALV infection of Jilin Province chicken farm was in general,and the ALV-J was the primary pathogen,the prevention,control and purification work of avian leukosis should strengthen.