从陕西省某养殖场送检的病鱼中分离到 1株革兰氏阴性杆菌 ,培养特征观察和生化特性分析结果证实为嗜水气单胞菌 ;小鼠和金鱼致病性试验证实分离菌具有致病性 ;药敏试验结果表明该菌对链霉素、万古霉素等高度敏感 ,对羧苄青霉素、氟哌酸等不敏感。用该菌制成灭活苗免疫金鱼保护力可达到 80 %以上。 Gram-negative bacilli were isolated from diseased fish in a farm in Shaanxi Province. The results of culture characteristics and biochemical analysis showed that the bacterium was Aeromonas hydrophila. The pathogenicity test of mice and goldfish confirmed that the isolates Which is pathogenic. The result of drug sensitivity test shows that the strain is highly sensitive to streptomycin, vancomycin and so on, and is not sensitive to carbenicillin and norfloxacin. Inactivated vaccine produced by the bacteria immune goldfish protection can reach more than 80%.