人工感染雏鹅新型病毒性肠炎的病理形态学发展规律的研究

STUDIES ON THE PATHOMORPHOLOGICAL DEVELOPMENT OF EXPERIMENTAL GOSLING NEW TYPE VIRAL ENTERITIS

4 0只 2日龄四川白鹅口服感染雏鹅新型病毒性肠炎病毒 ,在不同阶段解剖发病和死亡雏鹅 ,电镜观察组织器官的病理变化发展规律。接种后第 2天 ,十二指肠绒毛顶部上皮细胞发生坏死、脱落。随着感染时间延长 ,上皮细胞的坏死、脱落迅速向绒毛基部发展 ,并伴随固有膜炎性细胞浸润和坏死 ,病变向着空肠段发展。进一步发展为纤维素性坏死性肠炎 ,于小肠中后段形成假膜包裹肠内容物的栓塞物或直接由纤维素性渗出物与坏死肠粘膜混合凝固形成栓塞物阻塞肠腔 ,使外观膨大。肺充血和出血。肾充血、出血及肾小管上皮细胞变性。部分病例肝颗粒变性、脂肪变性。后期部分病例气管、腺胃上皮细胞脱落。早期部分病例心充血和出血。食道、胰腺及脑正常。电镜下可观察到小肠上皮细胞核畸形、固缩、核仁消失、核膜模糊和胞核崩解 ;胞浆严重空化 ,形成含有很多病毒粒子的“封入体” ;粗面内质网扩张呈囊状 ,其上的核蛋白体严重脱落 ;线粒体外膜破裂或嵴断裂及空化 ,部分受到损害的线粒体充满大量的病毒粒子 ;形成肠道栓子的外层假膜有大量的病毒粒子、细菌以及坏死的肠上皮细胞。肝脏细胞粗面内质网严重扩张及部分线粒体肿胀、脊断裂 ;而心肌细胞粗面内质网的轻度扩张及胞核畸形。

WT5BZ]40 two day old goslings were experimentally infected with Gosling New Type Viral Enteritis Virus (NGVEV) by oral administration.The infected goslings were killed at 24,48,72 and 96 hours postinfection,respectively.The dynamic lesions of the duodenum,ileum,heart,liver,lungs,kidneys,spleen,pancreas,brain,esophagus,gland stomach and trachea from killed and died goslings were studied exhaustively.The first picture of changes found in the duodenum was necrosis and slough of the epithelial cells from the villus tip at 48 hours postinfection.Then necrosis of the epithelium progressed to the villus base quickly.Meanwhile,the number of inflammatory cells infiltrating in the lamina propria increased gradually,necrosis occurred in the lamina propria and went down to the ileum gradually.Along with the aggravation of these changes,the fibrinous necrotic enteritis appeared in the small intestine,especially in the middle or lower parts of the small intestine.As a result,a typical coagulative embolus occurred and blocked up the intestinal cavity.Hyperemia and haemorrhage occurred in the lungs.Hyperemia,haemorrhage necrosis of the epithelial cells occurred in the kidneys.Hyperemia and haemorrhage were seen in some early infected hearts.The pancreas,brain,esophagus were normal,When observed with electron microscope,the nuclei of small intestine epithelial cells became deformity、pyknotic nucleolus disappeared,the nuclear structure was not clear and nucleus disaggregated.Vacuolation structure appeared in the cytoplasm.occlusion body fored in the cytoplasm with large amount of virion filled in it.Rough endplasmic reticulum in the cytoplasm expanded heavily and a large amount of ribosome sloughed off.The outer membrane of Mitochrondria(Mi)broke or Mi inflated、cristae broke and disappeared,some damaged Mi filled with large amounts virions.Contents of the small intestine were constisted of many bacteria,large amount of virions and lots of materials from necrotized and disintegrated epithelial cells.The difference of pathomorphological between Gosling New Type Viral Enteritis and Goslins Plague was discussed in this paper. [WT5HZ]