鸭短喙与侏儒综合征病毒分离与鉴定OA北大核心CSTPCD

A disease characterized by short beak,long tongue,and poor growth was observed in a cherry valley duck farm in Shandong,suspected to be infected with short beak and dwarfism syn-drome virus(SBDSV).This study aimed to isolate and identify the virus,and to test its pathoge-nicity to cherry valley ducks.First,the infection of short beak and dwarfism syndrome virus was confirmed by clinical symptoms,pathological changes,and PCR detection of the diseased materi-als.Second,after isolating and culturing the virus in SPF duck embryos,it was observed by elec-tron microscopy and analyzed by homology and phylogenetic tree,and then the EID50 of the virus allantoic fluid was tested.Finally,in the animal reversion test,2-day-old cherry valley ducks were orally administered with allantoic fluid,and the pathogenic characteristics were observed,as well as the virus distribution was detected by PCR and indirect immunofluorescence assay.The results showed that SPF duck embryos died at 96-120 hours post-inoculation,and virus particles of 20-50 nm in size were observed by electron microscopy.The allantoic fluid had an EID50 of 10-4,85·0.2 mL-1.The allantoic fluid was positive for SBDSV by PCR,confirming the successful isolation and cultivation of SBDSV from duck embryos.The main clinical manifestations of this case were short beak and weight loss.The virus was shed continuously for two weeks after infec-tion.The VP 2 fragment had a 99.8％similarity with the sequence of duck short beak and dwarf-ism syndrome virus,indicating that it was caused by the infection of this virus,which was named SBDS-SD strain.In the animal challenge experiment,clinical symptoms similar to those of the natural case,such as short beak,diarrhea and significant weight loss,were observed.This ex-periment successfully isolated a strain of short beak and dwarfism syndrome virus and verified its pathogenicity to cherry valley ducks,providing a basis for further research on this disease.