【摘要】 牛口蹄疫病毒(FMDV)持续感染是当前口蹄疫(FMD)防控的难题。在实验室条件下，以疫苗免疫后进行攻毒保护试验的牛为试验动物模型，选取攻毒28 d后无临床症状，但咽喉分泌物(O/P液)病毒核酸为阳性的个体作为持续性感染研究对象。通过qRT-PCR检测组织中的病毒核酸载量(Ct值)、HE染色观察组织病理变化及免疫组织化学染色定位病毒抗原，系统分析FMDV持续感染牛体内病毒在各组织中的分布特征。qRT-PCR结果显示，FMDV在持续性感染牛体内的分布具有组织特异性，病毒核酸主要富集于腭扁桃体、鼻咽扁桃体和O/P组织中；HE染色和免疫组化结果显示，扁桃体和O/P组织中可见部分淋巴细胞坏死和出血等病理改变，但都呈现较弱的病毒抗原阳性信号。更多还原

【Abstract】 Persistent infection with the Foot-and-Mouth Disease Virus(FMDV) in cattle is a current challenge in the prevention and control of Foot-and-Mouth Disease(FMD).In this study,cattle that had undergone post-vaccination challenge protection tests under laboratory conditions were used as the experimental animal model.under laboratory conditions,cattle that had undergone post-vaccination challenge protection tests were used as the experimental animal model.Individuals that showed no clinical symptoms 28 days post-challenge but tested positive for viral nucleic acid in oropharyngeal(O/P)fluid were selected as subjects foto investigater studying persistent infection.The distribution characteristics of FMDV in various tissues of persistently infected cattle werewas systematically analyzed using quantitative real-time PCR(qRT-PCR) to detect viral nucleic acid load(Ct value) in tissues,Haematoxylin and Eosin staining to observe histopathological changes,and immunohistochemical staining to localize viral antigens.The qRT-PCR results revealedshowed that FMDV distribution in persistently infected cattle exhibited tissue specificity,exhibits tissue specificity,with viral nucleic acids predominantly enriched in the palatine tonsils,nasopharyngeal tonsils,and O/P tissues.The results from H & E staining and immunohistochemical staining showed that pathological changes such as partial lymphocyte necrosis and hemorrhage were observed in the tonsils and O/P tissues,along with weakly positive signals for viral antigens in these tissues.更多还原