番鸭中网状内皮组织增生症病毒感染的检测

Evidence of Viral Reticuloendotheliosis in Muscovy Ducks

网状内皮组织增生症病毒(reticuloendotheliosis virus,REV)是一种可感染多品种禽的免疫抑制病病原,禽类感染REV后会导致机体发生免疫抑制并由此引发多种病原的继发感染(或混合感染),给养禽业造成极大损失。本研究利用针对REV基因组长末端重复序列(long terminal repeat,LTR)的特异性引物,对21份2013年收集的福建(12份)和浙江(9份)两省的番鸭源病料(肝脏和脾脏组织)进行检测。其中来源于福建漳州(1株,记为REV-FJ-MD01)和浙江宁波(1株,记为REV-ZJ-MD01)的番鸭源病料检测到REV感染阳性。将目的片段经克隆后进行序列测定分析发现,REV-FJ-MD01和REV-ZJ-MD01在该扩增区域的核苷酸同源性为100%,与GenBank中的REV参考株(除鸽源REV和鸭源713株仅1个碱基差异外)核苷酸同源性也为100%;从遗传进化关系可以看出,REV-FJ-MD01和REV-ZJ-MD01与REV参考株遗传进化较近,处于相同的遗传进化分支。本研究首次证实在福建番鸭中存在REV感染。

The diseases caused by reticuloendotheliosis virus （ REV ） are generally characterized by immunosuppression occurred to avian species. They can result in the increased susceptibility to secondary bacterial or viral infections and poor immune responses to vaccines on the infected birds. An epidemic of the viral diseases can lead to disastrous impacts for the poultry industry. This study employed the specific primers-pair targeting the long terminal repeat of the virus genoinic sequence for an investigation on 21 samples from the infected Muscovy ducks （12 from Fujian and 9 from Zhejiang） collected in 2013. Among the samples, one from Fujian （designated as strain REV-FJ-MD01） and another from Zhejiang （designated as strain REV-ZJ-MD01） were identified for further study. The positive fragments were harvested, cloned, and sequenced. The obtained sequence shared a perfect nucleotide identity with other GenBank REV isolates, except the pigeon-origin REV and the duck-origin REV strain 173, which differed on only one nucleotide. The genetic evolutionary relationship between the two strains and REV appeared close. Therefore, it was concluded that REV infection existed in the Muscovy ducks in Fujian.