山东省某规模化兔场GI.1a型兔出血症病毒的分子特性分析OA

In October 2023,female rabbits vaccinated with rabbit haemorrhagic disease(RHD)vaccine in an intensive rabbit farm(with a stock of 2 000 female rabbits)in Shandong Province suffered from dysphoria,increasing body temperature and sudden death.In order to find out all causes leading to the disease,tissues from 4 dead rabbits were collected for bacterial isolation and nucleic acid detecting,and rabbit haemorrhagic disease virus(RHDV)isolated from one positive sample(named as S1001)was genotyped and analyzed for genetic evolution.The results showed that no bacteria was isolated,and all the 4 samples were positive for RHDV;S1001 fell into RHDV GI.1a genotype,and its p16,p23,p29 and VP10 genes all belonged to GI.1a branch;compared to the vaccine strain(NJ strain),the nucleotide homology of VP60 gene was 95.9%,and 9,8,11 and 2 amino acid mutations were respectively present in p16,p23,p29 and VP10 protein.The results of protein structure prediction showed that N-terminal lamellar structural region of S1001 VP60 protein obviously changed,its structure was 93%similarity to that of the reference strain,and TM-score was 0.59(the closer to 1 it was,the more similar its structure became).In conclusion,RHDV infection was available in the farm,more molecular differences were observed in the infected RHDV compared to the vaccine strain,and VP60 protein antigenicity might be changed by protein conformational changes.Therefore,genetic variation of RHDV should be continuously monitored to timely know any variation,with a view to laying a foundation for the development of a novel vaccine.