2019-2022年广西鸭圆环病毒分子流行病学研究OACSTPCD

[Objective]The aim of this experiment was to understand the genetic and evolutionary characteristics of Duck circovirus(DuCV)in Guangxi.[Method]A total of 761 clinical samples of ducks were collected from Guangxi during 2019-2022 to detect DuCV infection by Real-time quantitative PCR.The whole genome sequence of DuCV was amplified by PCR,the similarity of nucleotide and amino acid sequences between DuCV and reference strain were analyzed by DNAStar,the DUCV recombination event was analyzed by RDP4 and SimPlot 3.5.1 software,and the genetic evolution tree was constructed by Mega 7.0 software.The amino acid variation sites of DuCV Cap protein were analyzed by BioEdit software.[Result]The positive rate of DuCV was 22.5％,and the genome size was between 1 988-1 996 bp.The nucleotide sequence similarity of the whole genome,Rep and Cap genes between the Guangxi DuCV strain and the reference strain was 71.9％-99.6％,83.1％-99.9％and 52.8％-99.9％,respectively.Gene recombination analysis showed that there were recombination events in DuCV-GX13-2019 and DuCV-GX14-2020.A total of 78 amino acid sites in Cap protein were mutated.Compared with DuCV-1,DuCV-2 was completely mutated at amino acids 3,12,15,23,31,42,56 and 64.The strains in Guangxi were DuCV-1 and DuCV-2 genotypes,DuCV-1 was the main dominant strain,and DuCV-1b subtype was the most widely prevalent.[Conclusion]The incidence of DuCV infection in Guangxi was serious,some strains had recombination events,the mutation rate of Cap protein was high,and various subtypes of DuCV were prevalent,which provided basic data for the epidemiological investigation of DuCV in Guangxi.