Epidemiological Investigation Of Subgroup J Avian Leukosis In Parts Of Anhui And Hubei From 2015 To 2017

Subgroup J of avian leukosis(ALV-J)is a new subtype of Avian leukosis isolated from the broiler by Payne British scientists.It causes tumors,causes chicken death,and cause chicken immunosuppression.In recent years,The disease is prevalent in china’s poultry industry,which has caused serious damage to the poultry industry.First of all,25 cases were received in anhui province from2016 to 2017,and 16 samples were collectd.By means of PCR amplification of the nine cities and counties in anhui province in 2016-2017 suspected 16 sick chicken detection,gp85 gene amplification,sequencing and comparative analysis,Ten subgroup J avian leukosis virus isolates were detected.The nucleotide homology is 86.0%-100%,the amino acid homology is 53.2%-100%,the nucleotide homology with domestic and foreign reference stains is92.7%-100%,the amino acid homology is 83.0%-98.7%,10 isolates were closely related.Secondly,this study carried out an epidemiological investigation on the subgroup J of avian leukoisis in hubei province from 2015 to 2017.A total of 1760 eggs,706 in serum and 854 cloacal swabswere 10 collected from hubei chicken farms.There were 10 suspected ALV-J infected chickens.10 strains of avian leukosis virus were successfully isolated from tissue and egg whites.Using the IDEXX company P27 antigen detection kit,the sample was tested.The positive rate of P27 antigen was 13.12% and the positive rate of gp85 antibody was 11.64%.The nucleotide and amino acid sequence identities of the 10 isolates were respectively 91.3%-100%,86.4%-100%,The nucleotide and amino acid homology with the domestic and foreign references strains were 83.5%-100%,followed by Nucleotide homology 82.7%-100%.The nucleotide homology with the prototype stain HPRS-103(9/10)is 96.8% to 98.9%and above one branch,only the JM6194 strain shares 91.6%,nucleotide homology with HPRS-103,and the other nine the genetic distance is far away.In the end,YC1714 strain and LHK1716 strain were selected from the local chicken ALV-J isolates for the whole gene sequence analysis.Comparing this sequence with another completed whole genome sequence showed that the homology of the gag and pol genes of ALV-J is 95%-98.1%,while the env gene homology is 82.8%-91.5%.Part 3 of the 3’ UTR appears.Loss of components,completely missing rTM segmentThrough detection and investigation of the Anhui and Hubei provinces and analysis of the gp85 gene sequence,a preliminary understanding of the infection of ALV-J in Anhui and Hubei regions,the variation trend of the gp85 gene of ALV-J in three years was relatively stable.In the Hubei and Anhui homology comparisons,evolutionary trends of the gp85 gene were different in Anhui and Hubei.