鮸鱼弧菌病病原菌(哈维氏弧菌)的分离与鉴定

Isolation and identification of the pathogenic strain of Vibrio harveyi from Miichthys miiuy

【目的】2009年春季,浙江省舟山地区养殖鮸鱼暴发弧菌病。症状主要表现为体表病灶部位出血、肌肉溃烂、内脏器官有白斑等。【方法】从病鱼体表溃疡部位及内脏分离出优势菌株090212,经人工感染证实该菌即为致病菌。通过API系统和菌体常规形态特征、培养特性和生理生化反应指标测定以及16S rRNA测序分析等综合鉴定,【结果】确认090212为哈维氏弧菌(Vibrio harveyi),该菌为革兰氏阴性,菌体呈短杆状,极生单鞭毛。该菌对氟苯尼考、四环素等5种抗生素敏感。【结论】哈维氏弧菌是海水养殖鱼类的常见致病菌,但作为养殖鮸鱼的病原菌尚属首次报道,将对鮸鱼的病害防治和健康养殖具有重要的指导意义。

[Objective]An outbreak of disease on the cultured Miichthys miiuy occurred in Zhoushan of Zhejiang province. The symptom displayed as skin ulceration and the inside apparatus turned white. [Methods]We isolated a dominant bacterial strain from the diseased Miichthys and assigned it as strain 090212. The artificial infection test proved that the isolate 090212 was the pathogenic bacterium that caused the disease. We applied physiological and biochemical characterization and API system in the bacterial classification. In order to confirm the result, we amplified a 1458bp sequence of 090212’s 16S rDNA and compared with other Vibrio in GenBank. [Results]The results turned out that 090212 was Gram negative and short rod with single polar flagellum. Homology analysis and phylogenetic study showed that strain 090212 had the highest similarity to Vibrio harveyi, with 99% identity. The sensitivity test of strain 090212 to 28 kinds of antibiotics revealed that the pathogen was sensitive to drugs such as Florfenicol and Tetracycline. [Conclusion]This paper revealed for the first time that the causative pathogen, Vibrio harveyi, lead to the mass mortality of Miichthys, which will be helpful in the disease control and health management during Miichthys cultivation.