日本鳗鲡肝肾病原菌及其防治中药的研究

Investigations into the Pathogenic Bacteria from Liver and Kidney of Anguilla japonica and the Chinese Herbals for Controlling

从发病日本鳗鲡(Anguilla japonica)的肝脏和肾脏分离到优势菌并命名为AJL01,经人工感染试验证实该菌为引起日本鳗鲡肝肾病的病原菌,其半数致死量为2.6×103 cfu/g;通过菌体、菌落形态特征、GYZ-15EV鉴定系统和16S rDNA同源性等综合鉴定分析,确认AJL01为迟钝爱德华氏菌(Edwardsiella tarda);采用五倍子、大黄、石榴皮、虎杖、黄芩5种中药单用及其两两配伍组成的10种复方对该菌进行抑菌试验,结果显示:单用时均可抑(杀)该菌,抑菌浓度(MIC)和杀菌浓度(MBC)相同,均为0.5～3.0 mg/mL;10种复方中6种呈现显著协同或协同作用,其中大黄+石榴皮、石榴皮+虎杖、五倍子+大黄3种复方可显著协同抑制该菌生长,FIC<0.5,MIC和MBC均不大于0.47 mg/mL.

A dominant strain of bacteria which was isolated from the liver and kidney of the diseased Anguilla japonica was named as AJL01.Artificial injection test proved that bacteriaum AJL01 was the pathogenic bacteriaum that triggered this ulcer disease.It was also showed that E.tarda was virulent against eel with a LD50 value of 2.6×103cfu/g.According to morphogenetic features,physiological and biological characteristics and 16S rDNA homology comparison of the bacteriaum,the pathogenic bacteriaum was Edwardsiella tarda;Moreover,the minimum inhibitory concentration（MIC）and minimum bactericidal concentration（MBC）of five Chinese herbals and their combination compounds between each other against Edwardsiella tarda were measured.The results showed that five Chinese herbals could kill Edwardsiella tarda,the range of MIC and MBC were from 0.5 mg/mL to 3.0 mg/mL.Six of the ten compounds could synergistically inhibit the growth of the bacterium,especially the Rheum Palmatum and Puncia Granatum,Puncia Granatum and Rhizoma Polygoni,Scutellaria Baicalensis and Rheum Palmatum.The FIC was less than 0.5,and the MIC and MBC less than or equal to 0.47mg/mL.