Morphological changes and virus distribution in the ileum of colostrum-deprived calves inoculated with non-cytopathic bovine viral diarrhoea virus genotype-1.

摘要: Eight colostrum-deprived calves were inoculated intranasally with a non-cytopathic strain of bovine viral diarrhoea virus (BVDV) genotype-1 and killed in batches two at 3, 6, 9 14 days post-inoculation (dpi). Two non-inoculated animals similar background served as controls. All infected developed mild pyrexia transient leucopenia due primarily to lymphopenia. Viraemia was correlated body temperature inversely related leucocyte count. Ileal Peyer's patches follicular lymphoid depletion from 3dpi. This change accompanied by cellular fragmentation pyknosis, characteristic apoptosis, which most prominent 6dpi. Lymphocyte apoptosis confirmed ultrastructural examination. Stellate cells macrophages located the follicles identified 3dpi number these increased until 9dpi. Fewer lymphocytes expressed BVDV antigen. Macrophages had morphological features consistent activation secretory phagocytic function These findings suggest that is only directly responsible for destruction small lymphocytes. Although lymphocyte infection coincided onset intensity disproportionate marked gut-associated tissue, particularly during early stages this process. Characterization indirect pathogenic mechanisms involved associated will require additional study.