High water temperature treatment for the control of Gluger pleceglassi infection of cultuned ayu, Plecoglossus altivelis

建立了一种高水处理方法，可有效地防治黄斑病。用人工感染的鱼通过口服给药孢子。在给予孢子后11 ~ 26天，在29℃的温度下维持5天，然后在第一次处理后7天进行同样的处理，鱼的Glugea囊肿完全消失。当自然感染的鱼得到类似的处理时，得到了类似的结果。纯化了Ayu免疫球蛋白，并建立了一套ELISA系统来检测针对整个孢子的抗体。早在给ayu口服孢子10天后就检测到抗体。经Uvitex 2B染色证实，该抗体是针对注射孢子产生的。以感染率为30%的虫卵为研究对象，经高温水处理后，通过口服活孢子对虫卵进行攻毒试验。结果，没有确凿的证据表明这些鱼通过治疗获得了对微孢子虫感染的免疫力，尽管在一些鱼身上发现了抗体水平的升高。对照鱼（处理过但没有挑战过）的感染率明显低于挑战过的鱼，囊肿数量也少于挑战过的鱼，这一事实证实了治疗方法的有效性。

A high water treatment method has been established against Glugea plecoglossi-infected ayu. Plecoglossus altivelis, using artificially infected fish through oral administration of spores.Glugea cysts completely disappeared after fish were maintained at 29ﾟC for 5 days 11-26 days after the spore administration, followed by the same treatment 7 days after the first treatment. A comparable result was obtained when naturally infected fish were similarly treated.Ayu immuno-globlin was purified and an ELISA system has been established to detect antibodies against whole spores. The antibody was detected as early as 10 days after oral administration of spores to ayu. Since spores taken from the intestinal surface of ayu were confirmed by the Uvitex 2B staining, it was thought that the antibody was produced against the injested spores.Using ayu with a 30% prevalence of infection at the start, challenge tests were conducted through oral administration of live spores to ayu after treatment with high temperature water. As a result, no firm evidence was obtained that the fish had acquired immunity against the microsporidian infection through the treatment, though elevation of the antibody levels were recognized in some fish. The fact that control fish (treated but not challenged) had a significantly lower prevalence of infection and smaller number of cysts than challeged fish confirmed the efficacy of the treatment method.