牙鲆出血性败血病病原的初步研究

Preliminary Study on the Pathogen of Haemorrhagic Septicaemia of Flounder ( Paralichthys olivaceus )

经病原菌的分离、纯化、人工感染和生理生化测定 ,认为变异微球菌为牙鲆出血性败血病的病原菌。菌体为圆形或椭圆形 ,单个、成对排列或成短链、四联及不规则的堆团。单个菌大小为 0 .5～ 1.8μm。无鞭毛 ,不运动 ,无牙孢 ,无荚膜。革兰氏阳性 ,不抗酸。好氧菌、葡萄糖 O- F试验为氧化型。测定的2 2种糖苷醇类中 ,仅葡萄糖、D-果糖、蔗糖、麦芽糖、甘油为好氧产酸 ,D-甘露糖弱产酸 ,且均不产气。氧化酶、过氧化氢酶阳性 ,硝酸盐还原、美兰还原为阳性。甲基红、V- P反应为阳性。能水解明胶、马尿酸钠 ,不能水解七叶苷、淀粉。不产生硫化氢、吲哚。不能利用柠檬酸盐、丙二酸盐。精氨酸双水解酶、赖氨酸脱羧酶、鸟氨酸脱羧酶、脲酶阴性 ,卵磷脂酶、凝固酶阳性。不溶血。先锋霉素、氯霉素、青霉素。

The present paper is on the pathogen of the bacterial haemorrhagic septicaemia of flounder ( Paralichthys olivaceus ). The typical external symptom was large area diffused haemorrhages on the body surface, the jaw and the base of the fins. After the strain M3 of the isolates injecting into the flounder, the symptom was similar to that of natural incidence. Then, the strain RM was isolated from the artificial infected flounder and its characters were the same as those of M3. The pathogens matched colsely the species description of Micrococcus varians. They were non motile, non sporing, Gram positive, non acid fast, oxidative, spherical or void cells of approximately 0 5 1 8μm in size. The cells occurred singly, in pairs, in short chains or in irregular clusters. Catalase, oxidase, coagulase, arginine dihydrolase, lysine decarboxylase, ornithine decarboxylase, phenylalanine deaminase, urease, and galactosidase were produced, but no H 2S and indole. Methylred test, V Preaction were positive. Nitrate, methylene blue were reduced. Gelatin, sodium hippurate, but not aesculin, starch were degraded. Citrate and malonate weren't utilized. Organisms produced acid from glucose, D mannose, sucrose, maltose, glycerin and D mannose, but not from L arabinose, D xylose, rhamnose, D galactose, sorbiose, lactose, melibiose, trehalose dihydrate, raffinose, lnulin, sorbitol or inositol. No gas was produced from these carbohydrate. Sensitivity was displayed to cefalosporing, chloraphenicol, penicillin and erythromycin.