甘肃源牛病毒性腹泻病毒的分离鉴定及全基因序列分析OA

[Objective]The purpose of this experiment was to understand the prevalence and molecular characteristics of Bovine viral diarrhea virus(BVDV)in cattle herds in Gansu,and provide a reference for BVDV prevention and control in this area.[Method]Virus isolation was performed on previously identified BVDV-positive serum samples.The isolated viral strains were identified using an indirect immunofluorescence assay(IFA)with a monoclonal antibody targeting the BVDV NS3 protein.Based on the whole genome sequencing data of the isolates,phylogenetic and similarity comparison were conducted on the whole genome,5´-UTR,Npro,and E2 gene sequences.Bioinformatic analysis was performed on the key proteins Npro and E2 of the isolated strain.Additionally,the synonymous codon usage pattern of the isolate genome was analyzed.[Result]After inoculating BVDV-positive serum samples into MDBK cells and conducting blind passage for 5 generations,no typical cytopathic effects were observed.One non-cytopathic(NCP)BVDV strain was isolated and named BVDV 24GS-19,then submited to NCBI,and the accession No.:PV806860.1.IFA results showed that the isolated strain could be observed to produce specific red fluorescence when inoculated into cells.The similarity comparison showed that the isolated strain was 97.02%similar to the BVDV CH0513 strain(accession No.:MH901135.1),and genetic evolution analysis indicated that the strain belonge to the BVDV-1b type.Bioinformatics analysis revealed that the instability indices of Npro and E2 proteins of the isolated stranin were 49.11 and 57.61 respectively,and there were amino acid mutation sites and phosphorylation sites.E2 protein had N-glycosylation and C-mannosylation sites,and had two antigenic epitopes(250-269 and 687-706 amino acids).Analysis of the synonymous codon usage pattern revealed a preference for codons encoding proline,arginine,alanine,and threonine.[Conclusion]In this study,one NCP-type BVDV epidemic strain was isolated.Through genomic and genetic evolution analysis,it was identified as subtype BVDV-1b.It showed a high similarity to the isolated strain BVDV CH0513.This results provided data support for the prevention and control of bovine viral diarrhea in Gansu as well as the development of vaccines.