Identification and Sequence Analysis of Tembusu Virus Isolated from White-feather Mule Ducks

A viral isolate (named as ZZ40) was abtained from liver of white-feather mule ducks with irregular hemorrhagic hepatitis, and were identified as duck tembus virus (DTMUV) by RT-PCR. The virus was specifically neutralized by anti-DTMUV hyperimmune serum. Gene fregments were abtained by using three sets of primers aimed at viral structural genes, and shared no less than 99.1% nucleotide sequence identity with those of avian tembus viruses isolated recently, and no more than 88.6% with that of Mosquito-borne tembus virus MM-1775 strain. Phylogenetic analysis showed that ZZ40 strain clustal into the same clade with those duck viruses isolated recently. These results indicated that the white-feather mule ducks in this case was infected with duck tembusu virus, which has no abviously variation in antigenicity compared with those of the early isolates of duck tembusu virus from egg-laying duck.