大黄鱼(Larimichthys crocea)内脏白点病的病原分离和组织病理学观察

Isolation and identification of the causative agent and histopathology observation of white-spots disease in internal organs of Larimichthys crocea

【目的】确定大黄鱼"内脏白点病"的病原,初步分析该病的致病机理,为大黄鱼内脏白点病的防治提供部分启示。【方法】开展病原菌的分离、种类鉴定和人工感染试验等工作,同时通过石蜡组织切片的方法,观察病鱼的组织病理学变化。【结果】确定病原菌为恶臭假单胞菌。在病鱼的肝脏、肾脏、脾脏等组织中均能发现明显症状或病症,各组织均发生炎性病变,细胞变形或解体,在脾、肾等组织中,纤维组织增生,围绕菌体形成肉眼见到的"白点"。【结论】恶臭假单胞菌作为病原菌,引起大黄鱼内脏出现明显白点,其致病机理仍需进一步探讨。

[Objective] In order to find the pathogenic bacteria of white-spots disease in internal organs ofLarimichthys crocea. [Methods] Using the method of isolation and identification of the causative agent in combination with 16S rRNA sequencing to find the pathogenic bacteria.Besides it was determined by artificial infection. The tissue of diceased fish were pathologically analyzed by paraffin histological section techniques. [Results] The bacterium Pseudomo- has putida was responsible for the disease. Affected fish showed obvious inflammation and cell deformation or disintegration of the liver, kidney and spleen. [Conclusion] The conducted study was necessary in order to reveal the reason for the high mortality of cultured yellow croaker in the Xiangshan bay. Furthermore, the results of this study can help to early recognize such disease outbreaks, hence preventing drastic economic losses in the future.