摘要:
采集自胰腺发黄或出血的雏番鸭病料经RT-PCR检测为鸭1型甲肝病毒阳性后,接种11日龄非免疫番鸭胚获得一株病毒(命名为MPZJ1206)。该株病毒在不同温度下均不凝集鸡、鸭和绵羊红细胞;鸭胚中和试验表明蚀斑纯化毒可被经典的鸭1型甲肝病毒高免血清特异性所中和。该株病毒对7日龄雏番鸭的致死率为38.5%,病死鸭剖检病变与临床发病鸭相同,且从病死鸭脏器中回收分离到的病毒经鉴定仍为鸭1型甲肝病毒。应用鸭1型甲肝病毒VP1基因特异性引物从该株病毒克隆获得的714 bp的基因片段,与经典鸭1型甲肝病毒分离株Du/CH/LGD/111239 VP1基因的同源性最高,为99.1%,经遗传进化分析表明该株病毒属鸭1型甲肝病毒谱系。以上结果表明,雏番鸭胰腺炎是由鸭1型甲肝病毒感染所致,这一新病型明显不同于经典的鸭1型甲肝病毒感染引起的肝脏出血,鉴于此,建议将本试验分离株命名为胰腺型鸭1型甲肝病毒。
Abstract:
Samples came from Muscovy ducklings with yellowed or hemorrhagic pancreatitis were positive for duck hepatitis A virus-1 (DHAV-1) by RT-PCR.A virus strain (named as MPZJ1206) was abtained from Virus-containing allantoic fluid after inoculation of embryonated Muscovy duck eggs with DHAV-1-positive samples. The isolate shows no hemagglutinating activity with chickens, ducks or sheep red blood cells at different temperature.Plaque purified virus was specifically neutralized by anti-DHAV-1 hyperimmune serum.Seven-day-old Muscovy ducklings inoculated with the virus showed a mortality rate of 38.5%, and yielded the same pathological characteristics as those of clinical onset duck had.The virus strain also recovered from the pancreas of Muscovy duckling died in the trials.A 714-bp fregment gene was abtained by using a set of primers aimed at VP1 ORF gene, and shared 99.1% nucleotide sequence identity with that of classical DHAV-1 strain Du/CH/LGD/111239. Phylogenetic analysis showed that MPZJ1206 strain lay in the viral lineage of DHAV-1.The above results indicate that pancreatitis in Muscovy ducklings was caused due to the infection of duck hepatitis A virus type 1, and this pathotype is distincted from hemorrhagic hepatitis caused by classical duck hepatitis A virus, so it advised that the virus isolated in this study could be named as pancreatitis-type DHAV-1.