采用组织学方法,获得患诺卡氏菌病乌鳢的脾、肾、肝、肌、鳃、肠6种组织,利用组织切片及超薄切片电镜技术对患病组织的病理变化进行观察分析,探究该病的致病机制.解剖病理症状为:体表充血有溃疡,腹部膨大有腹水,脾、肾、肝等内脏有大量白色结节.组织病理显示:病鱼各器官组织普遍存在慢性肉芽肿,中心由坏死的组织碎片和聚生菌体组成,外围有大量的炎性细胞浸润,结节周围的实质组织主要表现为肿胀、萎缩、增生和坏死脱落现象.超微病理显示:宿主器官组织细胞扩张,细胞质内溶酶体增多,核肿大或固缩溶解,细胞器缺失溶解,线粒体嵴断裂消失呈坏死性病变,肾脏及肝脏细胞中有大量病原菌寄生,细胞发生脂肪、空泡及纤维样变.实验结果表明:乌鳢诺卡氏菌病的组织细胞结构发生明显的病理变化,肾脏、肝脏和脾脏等主要组织器官受到严重的损伤病变,从而影响鱼体的正常生理机能,最终导致死亡.
The spleen, kidney, liver, muscle, intestine and gill obtained from Ophicephalus argus infected with Nocardiosis are pathologically analyzed using tissue slices and ultramicrocut electron microscopy techniques. The pathogenic mechanism of this disease is then discussed. The anatomical symptoms show ulceration hemorrhage on surface, abdomen intumescence with ascites. Spleen, liver, kidney and other visceras show abundent white nodules. The histopathology indicate that chronic granulomatous is widespread in the organs and tissues of the infected fish, and its center consists of necrotic tissue fragments and poly wild type strain surrounded by a large number of inflammatory cell infiltration. In addition, parenchyma surrounding nodules reveal swelling, atrophy, hyperplasia and necrosis. The findings in ultrastructure indicate the expansion in host tissue cell, the increasing lysosomes in the cytoplasm and nuclear enlargement or condensation dissolved. Organelles are missed or dissolved, mitochondrial cristae are disappeared and become necrotic lesions. Kidney and liver cells carry abundent parasitic pathogens and fat, vacuoles and fiber degeneration occurred. The results manifest that pathological changes of Nocardiosis are widely found in the tissue cells, causing serious damage to body organs such as spleen, kidney and liver. The loss of the normal physiological metabolism is the major cause leading to their eventual death.