关键词：
类立克次体;鱼病;鱼类病理学;超微病理学;乌鳢
摘 要：
应用电子显微镜技术,观察了养殖乌鳢RLO感染主要内脏器官超微结构病理变化,并初步探讨了发病机制。观察发现:RLO寄生细胞明显肿大,胞质电子密度低,细胞器肿大、溶解,RLO可随肿胀、破裂的细胞进入组织间隙;在一些寄生细胞内尚发现变性的RLO。内脏组织细胞普遍肿大,细胞器分散、稀少,线粒体除明显肿胀、嵴断裂消失外,尚发现坏死性变化即出现致密核心或无定形的电子密度物质;粗面内质网扩张、破裂和脱颗粒;部分细胞内溶酶体增多,胞质内发现明显的髓鞘样结构;核肿大或核固缩、溶解,并可见核内出现髓鞘样结构和核包含物。
译 名：
ULTRASTRUCTURAL PATHOLOGICAL STUDIES ON RICKETTSIA-LIKE ORGANISM INFECTION IN A CULTURED FISH,OPHIOCEPHALUS ARGUS
作 者：
GUO Qiong-Lin,SUN Xiao-Feng,JIA Wei-Zhang and ZHOU Xiu-Xia(Institute of Hydrobiology,the Chinses Academy of Sciences,Wuhan 430072)
关键词：
Rickettsia-like organism(RLO);Fish diseases;Pathology;Ultrastructural pathology;Ophiocephalus argus
摘 要：
By transmission electron microscopy,the ultrastructural pathological changes of major internal organs,including liver,spleen and kidney,in rickettsia-like organisms(RLOs) infected fish,Ophiocephalus argus C.have been described,and the pathological mechanism has been discussed in this paper.Observation showed that RLOs host cells were swollen,electronic density of cytosplasm was low,organelles were swollen and ruptured,and numerous RLOs entered into intercellular spaces together with swollen and ruptured cells.RLO debris and degenerated RLOs were detected in some RLOs host cells.The tissue cells were swollen,organelles were scattered and seldom.Besides vacuolar degeneration and creare-broken,some necrosis changes such as non-shaped electronic dense inclusions were observed in swollen mitochondria.The rough endoplasmic reticula enlarged,ruptured,and numerous ribosomes sloughed from those membrane.Lysosomes in a part of cells increased,the concentric-arranged myelin bodies were found in cytoplasm.The nucleus swelled severely,with intra-nuclear myelin-like figures and intra-nuclear inclusions,pkynosis or karyolysis was also seen in some cells.The ultrastructural pathological changes of liver were observed mainly in hepatocytes,phagocytic cells,endothelial cells of blood vessels and connective tissue cells near to blood vessels.The nucleus of hepatocytes showed intra-nuclear myelin-like figures and intra-nuclear fatty inclusions.The marked and larger fatty-drops were also seen in hepatocytic cytosplasm.The ultrastructural pathological changes of spleen were found mainly in haematopoietic cells,reticular cells,phagocytic cells and endothelial cells of blood vessels,which was similar to those of the liver.RLOs were usually detected in the cytosplasm of macrophage,a special macrophage,which engulfed 3～4 degenerated cells,was also observed in the spleen.The most severe ultrastructural changes were noted in the kidney.The marked organelles rupture and extensive karyolysis occurred usually in RLOs infected cells of kidney.Based on the ultrastructural pathological observation,the three mechanisms on the pathogenesis for the snakeheaded fish(O.argus) infected by RLOs may be suggested:(i)Rupturing cell ultrastructure and interfering with normal metabolisms of host cells by large quantities of RLOs multiplication;(ii)Damaging membrane system directly by releasing toxin of RLOs;(iii)Resulting in thrombi and disseminated intravascular coagulation(DIC) by causing the ultrastructural pathological changes of the endothelial cells of blood vessels.
