@ARTICLE{Liu_X._Isolation,_2019, author={Liu, X. and Kong, X.}, volume={vol.22}, number={No 1}, journal={Polish Journal of Veterinary Sciences}, pages={163-171}, howpublished={online}, year={2019}, publisher={Polish Academy of Sciences Committee of Veterinary Sciences}, publisher={University of Warmia and Mazury in Olsztyn}, abstract={Duck viral hepatitis (DVH) is an acute and fatal disease of young ducklings characterized by rapid transmission and damages. The most important agent of DVH is duck hepatitis virus 1 (DHV-1). The effective control of DVH was achieved by active immunization of 1-day-old duck- lings with an attenuated DHV-1 virus vaccine. However, the attenuated virus might reverse to virulence. In this study, a DHV-1 strain, Du/CH/LBJ/090809, was identified and its genomic se- quences were determined. The genome of Du/CH/LBJ/090809 is composed of 7,692 nt excluding poly A and the virus was clustered into genotype A by comparing with other referenced DHV-1 strains. Du/CH/LBJ/090809 could lead to 30% mortality of 10-day-old specific pathogen free (SPF) ducklings. The virus was passaged serially in SPF chicken embryonated eggs and three vi- ruses, passage 16 (P16), P29 and P40, were selected for genomic analysis. P29 and P40 were used to evaluate the attenuation in duckling by inoculating the virus to 10-day-old SPF ducklings. Re- sults of vaccination-challenge assay showed that the inactivated virus P40 could evoke protection against the pathogenic parent virus. Nucleotide and amino acid sequences of the genomes of Du/ CH/LBJ/090809, P16, P29 and P40 were compared. Changes both in nucleotides and amino acids, which might be contributed to the decreasing in virulence by chicken embryo-passaging of DHV- 1, were observed. We speculated that these changes might be important in the adaption and at- tenuation of the virulent virus. Additionally, strains obtained in this study will provide potential candidate in the development of vaccines against DHV-1.}, type={Article}, title={Isolation, identification and attenuation of a pathogenic duck hepatitis virus type 1 in China, and complete genomic sequence comparison between the embryo-passaged, attenuated derivatives and their parent}, URL={http://journals.pan.pl/Content/109606/PDF/22.pdf}, doi={10.24425/pjvs.2018.125614}, keywords={duck hepatitis virus 1, pathogenicity, attenuation, mutant site}, }