嗜水气单胞菌在西伯利亚鲟体内的分布及其引起的病理学变化

【作者】 王文龙；

【导师】 钟妮娜；

【作者基本信息】 四川农业大学 ， 基础兽医学， 2010， 硕士

【摘要】 本研究系统分析了西伯利亚鲟人工感染嗜水气单胞菌分离株(SAH-1)后,病原在西伯利亚鲟组织中的分布及其病理学变化,揭示了SAH-1在感染西伯利亚鲟体内的分布与其所致各靶器官的病理损伤间的相互关系。用SAH-1分别经腹腔注射和菌液浸泡两种方式人工感染40尾500g±20g的西伯利亚鲟。同时设立10尾不接种SAH-1作为阴性对照。观察感染后鲟鱼的临床症状,分别于接种后12h、18h、24h、48h、72h剖杀。进行大体病变,组织病理学和细胞病理学观察。采用免疫组化方法检测组织中的病原分布。大体病变：注射组和浸泡组接种后12h和24h开始表现轻微的临床症状,48h和72h主要症状为：腹部膨大,有多量淡红色腹水,肛门四周、眼睛、硬鳞基部充血、出血及溃疡；肝脏苍白,肾脏暗红色；肠道和生殖腺可见坏死和出血。组织病理学观察：镜下可见肝脏、脾脏、肾脏、心脏、肌肉、肠道、胃及性腺等组织细胞不同程度的充血、出血、变性、坏死；特征性病变为急性肾炎,心肌炎,肠炎,出血性脾炎；肝脏和肠道血管壁出现内皮细胞肿胀；细胞病理学观察：骨骼肌、心肌、脾脏淋巴细胞、肝细胞、肾小管上皮细胞可见线粒体肿胀,嵴断裂甚至溶解消失,整个线粒体呈空泡状；内质网扩张；肌原纤维断裂、溶解、消失；肾小管上皮细胞胞质中发现SAH-1聚集。免疫组化法检测：注射组,12h各组织器官均未检测到阳性信号,18h和24h阳性信号首先出现在脾脏、肾脏、肝脏、心肌；48h后肠道、肌肉、胃及性腺出现阳性细胞。浸泡组：12h和18h各组织均未检测到阳性信号,24h阳性信号首先出现在脾脏、肾脏、肝脏、心肌；48h后肠道、肌肉、胃及性腺存在阳性细胞。结果显示：阳性信号主要位于感染细胞的胞质中,偶尔出现在组织间质中。SAH-1首先侵袭脾脏、肾脏、肝脏组织,然后分布到心肌、肠道、肌肉和性腺,脑组织中未检测到阳性信号。本实验SAH-1在西伯利亚鲟组织中的分布及其引起的病理学变化结果表明,SAH-1在西伯利亚鲟组织内的分布与其所致病理损伤之间存在正相关。更多还原

【Abstract】 The essay systematically analysed the distribution of pathogenic bacteria in tissue and the infected histopathological changes in Acipenser baerii infected with Aeromonas hydrophila isolates (SAH-1). The results showed there was interrelationship between the disposition and the infected pathological damages.40 Acipenser baerii (500g±20g) were infected with SAH-1 through peritoneal injection and bacterial soaking while 10 normal sturgeons were performed as negative control. The clinical symptom was observed. Acipenser baerii of each group were dissected after infection at 12h,18h,24h,48h,72h respectively. The samples were carried out through the gross lesions, histopathological and cytopathological observation.The Acipenser baerii of injected and immersed group showed apparent clinical symptoms in late experiment period. The sick fish was abdominal swelling. The bleeding and ulcer was showed around anus, eyes and the base of ganoid scale as well as inflamed anal and bloody water outflow. Liver, spleen and kidney became intumescent, soft and dark red. Mesentery and gonad had the hemorrhage spots. Intestine had gray mucus and no food. Besides, the hindgut bleeded severely.Histopathological observation showed that the heart, spleen, kidney, liver, intestine, muscle, stomach, gonads and other organs were hyperemia, hemorrhage, degeneration, necrosis. Charateristic lesions included actue nephrities, myocardities, enteritis and hemorrhagic inflammatory splenitis. Endothelial cell swelled at liver and intestinal blood vessels.Cytopathological observations showed that mitochondrial swelled at skeletal muscle, heart muscle, spleen lymphocytes, hepatocyte, renal tubular epithelial cells; cristae ruptured or dissolved; mitochondria was empty and endoplasmic reticulum expanded; myofibril ruptured, dissolved or disappeared; SAH-1 gathered in cytoplasmic of renal tubular epithelial cells.The results of immunohistochemical detection were as follows:Injection group:There was no positive signal at 12h post-infection; positive signals were first appeared in the heart, spleen, kidney, liver at 18h and 24h post-infection; positive signals appeared at the gut, muscle, stomach and gonad at 48h post-infection. Immersion group:There was no positive signal in each tissue at 12h and 18h post-infection; positive signals were first appeared in the heart, spleen, kidney, liver at 24h post-infection; positive signals appeared at the gut, muscle, stomach and gonad at 48h post-infection and the positive signals were mainly located in the cytoplasm of infected cells, and occasionally appeard in the intercellular substance. Aeromonas hydrophila first infected cardiac muscle, spleen, kidney, liver, intestines and other organizations, and then extended to the muscle and gonad while the brain tissue had no detected positive signals during the whole infection.The results of Aeromonas hydrophila distribution in sturgeon tissue and pathological changes of experimental infection group showed that the there was positive correlation between the distribution of Aeromonas hydrophila in the Siberian sturgeon and the infected pathological damage.更多还原