海水养殖真鲷弧菌病病原菌外毒素的分离、纯化及生物学活性

PURIFICATION AND CHARACTERIZATION OF THE EXOTOXIN Vm-Pm PRODUCED BY VIBRIO MIMICUS

1996年 6月初 ,对福建省平潭县真鲷网箱养殖场发生的弧菌病进行研究 ,并确定该病病原菌为最小弧菌 (Vibrio mimicus)。采用硫酸铵沉淀、DEAE-纤维素层析及 Sephadex-G1 0 0层析等方法对最小弧菌产生的外毒素进行研究。结果表明 ,该外毒素为单一的多肽 ,分子量为 3 0 .45 6 k D,对真鲷的 L D50 为 4.48μg,对真鲷等养殖动物的溶血性最强 ,对 Vero细胞的 CD50 值为 0 .48μg,肠毒性弱阳性。该外毒素与最小弧菌产生的其他毒力因子相比 ,性质独特 ,是一类新的毒力因子 ,建议命名为 Vm-

An extracellular toxin Vm Pm produced by Vibrio mimicus was purified by the procedures of salting out of ammonium sulfate, anion exchange chromatography on DEAE cellulose and gel filtration chromatography of Sephadex G100 Toxin Vm Pm is a polypeptide with a molecular weight of 30 456kD, as determined by SDS polyacrilamide gel electrophoresis.\;Pathogenicity of the heat labile toxin Vm Pm for red sea bream was evaluated. The toxin was quite pathogenic to red sea bream, and the LD 50 for red sea bream was 4 48μg. The toxin showed remarkable hemolytic activities for red blood cells from red sea bream, crucian carp, human and some other animals. The toxin exhibited a postive cytotoxic response for Vero cells and the CD 50 for Vero cell is 0 48μg. The enterotoxic activities of the toxin for rabbit is weak; it could cause only a little fluid accumulation in ligated rabbit ileal loops.\;Compared with other known toxic factors produced by Vibrio mimicus, toxin Vm Pm shows unique characteristics. It is a new toxic factor produced by Vibrio mimicus , therefore the authors propose to name the toxin 'Vm Pm' toxin.