Disease mechanisms of emaciation disease of tiger puffer

1)对消瘦虎河豚肠道中的粘孢子虫进行了寄生虫学检查，并对其形态特征和发育过程进行了研究。和粘菌属(Myxdium sp.)TP进行了描述。此外，根据Diff-Quik染色的肠道印迹和HE和Uvitex2B染色的组织切片，建立了上述粘孢子虫的诊断程序。2)组织病理学检查表明，粘液孢子属重度感染。茶多酚和河豚纤毛虫可引起虎纹伊蚊肠道上皮细胞的脱落和变性，而河豚鱼对肠道组织无明显损伤。通过摄食受感染的组织、与受感染的鱼共居以及暴露于装有受感染的鱼的池水中的流出物，将TP和M.fugu从鱼传播到其他鱼。4)粘虫的动力学。在实验感染的鱼中对TP进行了研究。研究发现，寄生虫的发育依赖于温度：它们在20摄氏度和25摄氏度时发育，而在15摄氏度时变得“神秘”。用粘菌实验感染鱼类。在20℃时，TP从第3周开始厌食，从第6周开始出现典型的厌食征象。20C.5)病鱼的吸湿能力显著低于未感染鱼，说明病鱼的渗透调节功能受到了阻碍。此外，受感染鱼的肝脏萎缩和肝脏指标(LDH、GOT和GPT)降低，表明消瘦的鱼在肝脏中存在功能障碍。6)证实了虎豚消瘦病的病原菌是肠道粘孢子虫。TP和河豚Leptotheca fugu.对寄生虫的传播方式和发育动力学进行了研究。粘孢子虫的严重感染导致肠道渗透调节明显紊乱，导致消瘦疾病。

1) Parasitological examinations of myxosporeans from the intestine of emaciated tiger puffer were conducted, and morphological characteristics and developmental processes of Myxidium fugu n. sp., Leptotheca fugu n. sp. and Myxidium sp. TP were described. Further, diagnostic procedures of the above myxosporeans were established based on Diff-Quik-stained intestine imprints and HE ＆ Uvitex2B-stained histological sections.2) Histopathological examinations indicated that heavy infections with Myxidium sp. TP or Leptotheca fugu caused exfoliation and degeneration of the intestinal epithelia of tiger puffer, while M. fugu caused no significant damage in the intestinal tissues.3) Myxidium sp. TP and M. fugu transmitted from fish to other fish by feeding the infected tissues, cohabitation with infected fish and exposure to effluent from a tank holding infected fish.4) Kinetics of Myxidium sp. TP were investigated in experimentally infected fish. Development of the parasites was found to be temperature-dependent : They developed at 20C and 25C, while they became "cryptic" at 15C. Experimentally infected fish with Myxidium sp. TP became anorexic from week 3 at 20C, and showed the typical sign of the from week 6 at 20C.5) Moisture absorbance ability of infected fish was significantly lower than that of uninfected fish, indicating that functions of osmotic regulation were hampered in diseased fish. Further, atrophy of the liver and reduced hepatic indicators (LDH, GOT and GPT) of infected fish suggested that emaciated fish had a functional disorder in the liver.6) The causative organisms of emaciation disease of tiger puffer were demonstrated to be the Intestinal myxosporeans, Myxidium sp. TP and Leptotheca fugu. Modes of transmission and developmental kinetics of the parasites were characterized. Heavy infections with the myxosporeans caused a significant disorder in osmotic regulations in the intestine, resulting in the emaciation disease.