In situ enzyme immunoassays with tissue smears to study horizontal transmission of BMNV in penaeid shrimp and in beach animals

An enzyme immunoassay technique is developed for detecting the baculoviral midgut gland necrosis virus (BMNV) in penaeid shrimp and beach anieds. An antiserum was obtained from rabbits immunized with a BMNV preparation Purified from Penaeus japonicus. γ-globulin was isolated and labelled with horseradish peroxidase (HRP). This reagent was used to detect the virus in penaeid shrimp experimentally infected with the BMNV preparation, in cultured penaeid shrimp and in several beach animals. The technique is specific, simple and sensitive and can be developed into a practical method for the detection of penaeid shrimp viruses. Among 128 tissue samples from 11beach animals, 77 samples gave positive reactions with the enzyme-labelled immunoglobulin against BMNV from P.japonicus. These animals could possibly constitute a horizontal transmission pathway for cultured penaeid shrimp viruses.

厦门地区杂色花蛤的病毒观察与检测

在厦门海区对虾养殖内外环境中，电镜观察发现了杂色花蛤肝胰腺的一种杆状病毒和两种球状病毒。杆状病毒大小为（８５～９０）ｎｍ×（２４０～２６４）ｎｍ，有包膜，存在于细胞核中，细胞质可见。一种球状病毒直径为７０～８０ｎｍ，有包膜，存在于细胞质中．另一种球状病毒直径为９５～１２０ｎｍ，有包膜，存在于细胞核中。用免疫酶组织化学法检测表明，杂色花蛤所带杆状病毒与ＢＭＮＶ有抗原性正相关，其检出率随季节变化，暗示自然生长且感染病毒的杂色花蛤可能是日本对虾杆状病毒病的传染源。

养殖日本对虾病毒的观察与分离

从患病毒病的日本对虾剥取肝胰脏组织切片后电镜观察发现，很多肝胰细胞核中有典型的杆状病毒，病毒粒子已成熟，具有清晰可见的包膜结构，两端钝圆，直径约７０～８０ｎｍ，长度约２５０～３００ｎｍ，有的整个细胞核中充满了未成熟的病毒粒子，核结构已瓦解，未观察到病毒包含体的存在，该病毒可能为ＢＭＮＶ．有的病虾标本肝胰细胞质中含有直径约５５～６０ｎｍ的具包膜结构的球状病毒．中肠中也发现了染色深的病毒颗粒，并有一些尚未成熟的病毒颗粒在微绒毛中形成串珠状结构，但均无发现病毒包含体．分别采用不同的提取方案从这些病虾中分离纯化了两种病毒，一为７０～８０ｎｍ×３００～３８０ｎｍ的ＢＭＮＶ；另一为直径约６０～６５ｎｍ的日本对虾球状病毒。