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从患烂尾病眼斑拟石首鱼(Sciaenops ocellatus)的溃疡处分离到一株优势菌So GZ1401,回归感染试验证实该菌是引起烂尾病的病原菌,对眼斑拟石首鱼的半致死量(LD50)为8.6×103 CFU·g~(-1);结合其形态学和生理生化特征及HSP60测序分析,鉴定为哈维氏弧菌(Vibrio harveyi);利用杯碟法研究其胞外产物性质,结果表明:其胞外产物具有淀粉酶、明胶酶、酪蛋白酶、卵磷脂酶、脂酶活性以及溶血活性,但无脲酶活性。药敏试验表明,该菌株对氟哌酸、恩诺沙星、氟苯尼考和复方新诺明等抗菌药有较高的敏感性。制备哈维氏弧菌灭活疫苗,采用注射和浸泡2种途径免疫眼斑拟石首鱼,测定受免疫鱼的血清抗体效价和疫苗对眼斑拟石首鱼的免疫保护率。结果显示,免疫组血清中的抗体效价水平均高于对照组,差异有统计学意义(P<0.05),注射组和浸泡组的抗体效价最高值分别达718.4和128,哈维氏弧菌攻毒后免疫保护率分别为75.0%~86.7%和46.4%~56.7%。哈维氏弧菌灭活疫苗对眼斑拟石首鱼具有较好的免疫保护性。
A dominant bacterium So GZ1401 was isolated from the ulcer of Sciaenops ocellatus, and the infection test confirmed that the bacterium was the causative agent of rotten-rot disease. (LD50) was 8.6 × 103 CFU · g -1. According to its morphological, physiological and biochemical characteristics and HSP60 sequencing, it was identified as Vibrio harveyi. The results showed that the extracellular products had amylase, gelatinase, caseinase, lecithinase, lipase activity and hemolytic activity, but no urease activity. Susceptibility tests showed that the strain of nifloxacin, enrofloxacin, florfenicol and cotrimoxazole and other antibacterials have a higher sensitivity. Preparation of Vibrio harveyi inactivated vaccine, injection and soaking two ways to immunocturnal fishes stonefish, measured by immunized fish serum antibody titer and vaccination of fish eye cobblestone immune protection rate. The results showed that the antibody titers in the serum of the immunized group were higher than that of the control group (P <0.05), the highest antibody titers of the injected group and the soaked group reached 718.4 and 128, respectively, After immunization, the rates of immune protection were 75.0% ~ 86.7% and 46.4% ~ 56.7%, respectively. Vibrio parahaemolyticus killed Vibrio parahaemolyticus has good immune protection.