实验性流行性腹泻仔猪小肠粘膜上皮细胞及肠系膜淋巴结的超微结构

给8头生后3d的哺乳仔猪经口感染猪流行性腹泻病毒(PEDV)“吉”毒株,于感染后18、30、45和96h各扑杀2头,以透射电镜和扫描电镜观察了小肠粘膜上皮细胞及肠系膜淋巴结的超微结构。结果表明,小肠上皮细胞的病变因感染时间不同而有明显差异。上皮细胞的脱落和残留上皮细胞超微结构的破坏,以感染后30h最严重,病毒在这些上皮细胞内的增殖最显著。感染后45h,见有大量新生上皮细胞修补损伤的肠绒毛。感染后96h,小肠绒毛短缩、粗大乃至发生融合。实验仔猪肠系膜淋巴结内巨噬细胞和淋巴细胞的超微结构均遭到破坏,在巨噬细胞内见有PED冠状病毒粒子。

Ultrastructures of Intestinal Epithelial Cells and Mesenteric Lymph Nodes in Piglets Experimentally Infected with Porcine Epizootic Diarrhea

Eight piglets were inoculated oro-nasally with PEDV "J" strain and were killed at 18,30, 45 and 96 h after inoculation by two piglets each time. The ultrasrtrutcural changes of the epithelial cells of small intestine and the mesenteric lymph nodes were examined by transmission and scanning electron microscope The results showed that the pathological changes of PED piglets were distinctly different in various infected period. The epithelial cells of small intestine were fallen off seriously. The ultrastructural lesion of theremaining cells was most severe and the virus proliferation in these cells was fastest at 30 h after inocuiaton. Defected tissae was covered with regeneratd epithelial cells in some portions of the intestinal villi at 45 h. It reflected a defensive reaction. The small intestinal villi were distorted, shortened and fused each other at 96 h. The PED virus particles in the macrophages of the mesenteric lymph nodes. The macrophages and lymphocytesin the mesenteric lymph nodes showed ultrastructural changes.