草鱼细菌性败血症的病原检测

Pathogen Detection of Bacterial Septicemia in Grass Carp

[目的]分离和鉴定草鱼细菌性败血症的主要致病菌。[方法]首先,采集患病草鱼的肝、脾、肾等器官,分别进行病原菌的分离培养;然后,将各自分离菌种进行镜检、生理生化指标鉴定以及16S rRNA基因序列测定;最后进行人工再感染试验。[结果]分离得到的菌株,经菌体形态、致病性、培养性状、生理生化反应和16S rRNA序列分析鉴定为同一种菌种,即嗜水气单胞菌。人工再感染的草鱼出现了与自然感染草鱼相同的症状。[结论]嗜水气单胞菌是引起草鱼细菌性败血症的主要致病菌。

[Objective] The aim of this research was to isolate and identify the major pathogen of bacterial septicemia in grass carp. [Method] Firstly, isolate and culture bacteria collected from livers, spleens, kidneies and other organs of infected grass carps ,respectively. Sencondly, microscopic examination, physiological and biochemical identification and sequence analysis of 16S rRNA were performed successively. Finaly, a set of healthy grass carps were infected artificially. [Result] These isolates were identified as Aeromonas hydrophila by morphological characterization, pathogenicity, physiological and biochemical reactions, and sequence analysis of 16S rRNA. The result of artificial infection test showed that pathogenic symptoms of the artificial infection grass carp was same as the infected grass carp. [Conclusion]Aeromonas hydrophila was the major pathogen of bacterial septicemia in grass carp.