克氏原螯虾暴发病细菌性病原的研究

The Bacterial Pathogen of Outbreak Disease in Procambarus clarkii

从患暴发病的克氏原螯虾(Procambarus clarkii)的肝胰腺中分离到3株细菌。人工注射感染显示,KSAX-3分离菌在浓度107cfu/mL时可使95%以上健康克氏原螯虾死亡;在106cfu/mL浓度时可导致70%的健康克氏原螯虾死亡,并使克氏原螯虾出现明显的与自然条件下相似的疾病症状,试验结果表明该分离菌为克氏原螯虾致病菌。KSAX-3菌的主要生理生化特性为:革兰氏阴性,单鞭毛,发酵葡萄糖,甘露醇、氧化酶、鸟氨酸脱羧酶、赖氨酸脱羧酶阳性,精氨酸脱羧酶、水杨酸、枸橼酸盐(西蒙氏)阴性,在含0%、10%NaCl的普通培养基中不生长,在含2%、4%、6%8、%NaCl的普通培养基中生长,在30℃、35℃、40℃、42℃条件下生长良好。鉴定该菌为副溶血弧菌(Vibrio parahaemolyticus)。药敏试验结果表明,该菌对盐酸土霉素、盐酸四环素、环丙沙星、诺氟沙星、金霉素、硫酸卡那霉素、交沙霉素、烟酸诺氟沙星等8种药物敏感。

Three bacterial strains were isolated from the hepatopancreas of the diseased Procambarus clarkii. Procarnbarus clarkii was injected with 0. 1 mL 10^7 cfu/mL isolated bacteria ＂KSAX-3＂ and about 95% healthy shrimps died. When the concentrate of the injected bacteria was 10^6 cfu/mL, about 70% shrimps died with the similar symptoms occurred in nature. Our results showed that the isolated bacteria was a kind of pathogen in Procarnbarus clarkia. This isolated bacteria was Gram negative, had one polar flagella and produced acid from glucose and mannite. When reacted with oxidase, aesculin and lysine,the results were positive. When reacted with arginine, salicin and Simmons citrate, the results were negative. This bacteria couldn＇t grow on the mediums which contained 0% and 10% NaCl. However,it grew on 2%,4%,6% and 8% NaCt. When at 30 ℃,35 ℃,40 ℃ and 42 ℃,the isolated bacteria grew very well. The target was identified as Vibrio parahaemolyticus. The drug sensitivity tests showed that the isolated pathogen was sensitive to oxytetracycline, tetracycline, ciprofloxacin, norfloxacin, aureomycinum, kanamycin, josamyein, norfloxaein.