妊娠母猪流产胎儿组织中PCV3的分子鉴定与病毒载量分析OA

To analyze the causes of abortion in pregnant sows,firstly,nucleic acids were extracted from 18 types of tissue samples of the aborted fetus and the target genes of 7 sow reproductive disor-ders pathogens were detected,such as porcine reproductive and respiratory syndrome virus,classical swine fever virus,porcine circovirus types 2,3,and 4(PCV2,PCV3 and PCV4),African swine fever virus,and porcine parvovirus,by RT-PCR,PCR,and multiplex fluorescence quantitative PCR.Secondly,viral load of the major pathogen in tissue samples of the aborted fetus was determined based on the estab-lished standard plasmids and the plotted standard curves.Finally,whole-genome sequencing and analy-sis of the major pathogen were performed.The results revealed that among the 7 pathogens tested,the aborted fetus was primarily infected with PCV3.This pathogen,designated as PCV3-GS0304/2024,was de-tected in 18 types of tissue samples from the aborted fetus,with its predominant presence observed in the lungs,stomach,throat,tonsils,oral mucosa,and mesenteric lymph nodes,ranging from approximately 1 × 105 to 4× 105 copies/μL.The PCV3-GS0304/2024 belonged to the PCV3b subtype.Both its genome and Cap amino acid sequences exhibited high conservation,notably featuring the H19R mutation.This study clarified the single infection status and tissue distribution characteristics of the PCV3b subtype in porcine abortion cases in Gansu Province,providing a crucial reference for understanding the preva-lence and infection of PCV3 and facilitating its prevention and control.