嗜麦芽寡养单胞菌胞外蛋白酶对斑点叉尾鮰的组织病理学影响  

Histopathological effect of Stenotrophomonas maltophilia extracellular protease on Ictalurus punctatus

作　　者：黄小丽[1] 舒秀梅 汪开毓[3] 邓永强[4] 耿毅[3] 

机构地区：[1]四川农业大学动物科技学院水产系,四川雅安625014 [2]双流县农村发展局,四川成都610041 [3]四川农业大学动物医学院,四川雅安625014 [4]四川省动物疫病预防控制中心,四川成都610041

出　　处：《中国兽医科学》2011年第5期453-458,共6页Chinese Veterinary Science

基　　金：教育部“长江学者和创新团队发展计划”创新团队项目(IRT0848)

摘　　要：采用硫酸铵盐析、DEAE-Sephadex A50凝胶层析等方法从嗜麦芽寡养单胞菌胞外产物中提纯了一种蛋白酶,将提纯的蛋白酶腹腔注射斑点叉尾鮰,研究了嗜麦芽寡养单胞菌胞外蛋白酶对斑点叉尾鮰的致病性以及引起的病理变化。结果发现,斑点叉尾鮰出现不同程度的死亡,其LD50为3.49μg/g。病鱼鳃丝肿胀;肝及肾肿大,质地脆,有大小不等的坏死区;脾肿大出血。组织学观察可见肝细胞肿胀,严重者空泡变性,大量细胞坏死、溶解消失;肾小管上皮细胞严重空泡变性,细胞淡染,逐渐溶解、消失,隐约可见细胞轮廓;脾严重出血,网状内皮细胞坏死;胃肠黏膜下层炎性水肿。超微病理学观察发现肝细胞糖原颗粒减少,细胞核染色质溶解,线粒体肿胀,线粒体嵴模糊不清;脾大量红细胞浸润,网状内皮细胞核染色质大量消失;肾小管上皮细胞刷状缘微绒毛肿胀,脱落;细胞核染色质减少,边移,核膜扩张;线粒体肿胀,滑面内质网扩张。扫描电镜观察发现胃肠道黏膜上皮细胞肿胀、坏死、脱落。证实,嗜麦芽寡养单胞菌胞外蛋白酶可致斑点叉尾鮰各组织器官出现不同程度的病理变化,特别是对肝、脾、肾、脑和胃肠道的影响较大。A protease was purified from Stenotrophomonas maltophilia using the salt fractionation with ammonium sulfate and DEAE-Sephadex A50 gel chromatography method. The injected fish appeared different death rate after intraperitoneal injection with the purified protease. The LD^0 was 3.49 /~g/g. At the same time,the injected fish expressed filaments,hepata and kidneys swelling and different necrotic are- as were observed. The spleens were swelling and haemorrhage. Histopathologically, hepatocytes swelled with severely vacuolar degeneration and lots of hepatocytes showed necrosis. The necrotic cells were fused and became a focal necrosis. The renal tubular epithelium expressed severe vacuolar degeneration with slightly staining and lysis. Spleen was hemorrhage and reticuloendothelial cells were necrosis. The submu cosa of gastrointestinal was edema. Ultrastructural pathological study showed the amount of glycogeno some in hepata decreased a lot,chromatin of hepatocyte nucleus dissolved, mitochondria swelling and vague cristae. A lot of red blood cells infiltrated spleen and chromatin of reticuloendothelial cells disappeared. Brush border of renal tubular epithelial cells swelled,fall off,and the chromatin of nucleus reduced,mitochondria swelling and smooth endo gastrointestinal mucous epithelium the extracellular protease of S. ma obvious pathological change. Key words： Stenotrophomonas plasmic reticulum were expanded. Scanning electron microscope found cells were swelling, necrosis, and fall off. The results demonstrated that ltophilia led the hepar,kidney, spleen, brain and gastrointestinal tract obvious pathological change.

关 键 词：嗜麦芽寡养单胞菌 胞外蛋白酶 斑点叉尾鮰 组织病理学 

分 类 号：S852.617[农业科学—基础兽医学]