关键词: 新型鸭肝炎病毒, 鸭甲型肝炎病毒, 分离鉴定, 反转录PCR

Abstract: A suspected duck hepatitis virus（JS strain） was isolated from clinical dead ducklings with duck hepatitis symptoms in Jiangsu. The isolates were passed in duck embryos and the titers were 10-438 ELD50·02 mL－1 to 10-617 ELD50·02 mL－1. Animal regression test showed attack ducklings could reproduce original disease of clinical symptoms and pathological changes. The virus was not sensitive to chloroform， diethyl ether， trypsin; The virus was stable to acid\|resistance （pH 30） but not stable to heat\|resistance. The JS strain of antigen was not related to the classic strain of DHV\|1 as showed by in vitro cross\|neutralization assay and in vivo cross\|protection test. The strain was amplified by RT\|PCR using specific primers designed according to the published sequence of DHV. The sequence of JS strain consisted of about 720 bp shared the high identities of 693%-933% with VP1 gene of DHV\|1. Furthermore， based on the deduced gene sequences， the phylogenetic analysis indicated that the isolates were highly homologous with the DHV strains isolated in Korea. Therefore， JS strain represents a new serotype of DHV occurred in China （designated N\|DHV\|JS strain）.

Key words: new serotype of DHV, duck hepatitis A virus, isolation and identification, RT\, PCR