鮰爱德华菌单克隆抗体的制备及其在黄颡鱼“红头病”研究中的应用

以黄颡鱼Pelteobagrus fulvidraco “红头病”病原---鮰爱德华菌 Edwardsiella ictaluri A86为抗原,利用杂交瘤技术制备了鮰爱德华菌黄颡鱼分离株的菌体单抗5D11、1B8、1G7、3G8、5A9、3H8,其效价分别为1：1280、1：1280、1：2560、1：320、1：160和1：80。结果表明：6株单抗与11株鮰爱德华菌黄颡鱼分离株均可以结合,与迟缓爱德华菌、气单胞菌、大肠杆菌、链球菌、弧菌等10株参考菌株均无交叉反应,单抗5D11和1B8可与鮰爱德华菌参考菌株结合。应用免疫荧光和免疫组织化学法检测了鮰爱德华菌对黄颡鱼的侵染规律。结果表明：黄颡鱼经人工注射鮰爱德华菌A86感染6 h后,在其肝、肾、脾、心、肠和胃中检测到了阳性细菌,其中脾脏中最多,心脏中最少；感染24 h后,脑中检测到阳性细菌；30 h后,鳃中显示有阳性信号；54 h后,在眼的外边缘检测到少量阳性细菌。研究结果可为进一步研究鮰爱德华菌在黄颡鱼体内的致病机理提供技术手段及基础,对揭示黄颡鱼“红头病”的发病机制具有重要意义。

Preparation of monoclonal antibody to pathogen Edwardsiella ictaluri and application in red-head disease of yellow catfish Pelteobagrus fulvidraco

Six hybridomas （5D11,1B8,1G7,3G8,5A9 and 3H8） were prepared from Balb/C mice immunized in-traperitoneally with Edwardsiella ictaluri A86（E. ictaluri A86）,a pathogen of red-head disease in yellow catfish Pelteobagrus fulvidraco, to secrete mAb against E. ictaluri A86, with valence of 1：1280 in 5D11, 1：1280 in 1B8, 1：2560 in 1 G7 ,1：320 in 3 G8 ,1：160 in 5 A9 and 1：80 in 3 H8 . Bacterial cross-reaction showed that these mAbs specifically recognized E. ictaluri A86, but showed no cross reactivity to other referred bacteria. It is worth noting that mAbs 5D11 and 1B8 were found to react with E. ictaluri referred strains. Immunofluorescence and immunohis-tochemistry test of the infection rule of E. ictaluri strains in yellow catfish showed that E. ictaluri was detected in liv-er, kidney, spleen, heart, intestines, and stomach as early as 6 h after infection, the maximum in spleen, and the minimum in heart;positive signal was found in brain 24 h later, and positive signal was found in gill 30 h after in-fection. With the time elapse, a small amount of positive bacteria was detected around the edges of eyes 54 h after infection.