褐牙鲆腹水症病原菌的分离鉴定及其灭活疫苗的研制

Isolation and Identification of Bacterial Pathogen Aeromonas hydrophila and Development of the Inactivated Vaccine in Japanese Flounder Paralichthys olivaceus Diseased with Ascites

从患腹水病褐牙鲆体内分离致病菌,通过生理生化和分子生物学方法进行鉴定;该菌的16SrDNA序列与标准株同源性达99.8%,证明该菌为嗜水气单胞菌。制备灭活疫苗后分别注射小鼠和牙鲆,测定其免疫效果。试验结果表明,用所制备的灭活疫苗免疫小鼠,其保护率达到90%,免疫牙鲆的保护率达到80%;采用渗透压差法浸泡免疫牙鲆在攻毒后发病率仅为6%,攻毒后保护率为85%;通过间接ELISA检测表明受免动物体内产生了较高水平的抗体;剖检及病理切片结果表明免疫过的动物内脏健康无异样,而未免动物肝脏充血,肠腔有积水。说明该疫苗安全有效。

The pathogenic bacteria were isolated from diseased Japanese flounder Paralichthys olivaceus, and identified as Aeromonas hydrophila by biochemical methods and polymerase chain reaction based on the 16s rDNA sequence on GenBank via the homologies of nucleic acids of 99.8% between the isolated strain and the standard strains. The mice and the flounder were immunized with the inactivated vaccine made by this isolated Aeromonas hydrophila via dipping immersion and showed protection rate of 90% and 80 % with the incidence of 6 %. The antibody level was detected by agglutination reaction and indirect enzyme-linked immunosorbent assay （ELISA） with the antiserum seemed immunogenic crucially. The anatomized results showed that the immunized mice were healthy and the unimmunized mice （as the control） were diseased in liver, indicating that the vaccine was effective.