豹纹鳃棘鲈病原鳗利斯顿氏菌的分离鉴定及生物学特性研究

IIsolation of Pathogenic Listonella anguillarumfrom Plectropomus leopardus and its Biological Characterization

从患病的豹纹鳃棘鲈(Plectropomus leopardus)的肾脏中分离到1株优势菌33002,人工感染试验证实其对豹纹鳃棘鲈有较强的致病性;采用形态学观察、生理生化特性分析及16SrRNA和gyrB基因序列系统发育树分析对菌株33002进行鉴定。结果显示,菌株33002为革兰氏阴性弧菌,生化特性与利斯顿氏菌属的鳗利斯顿氏菌(Listonella anguillarum)相近,基于gyrB基因序列的系统发育分析,菌株33002与鳗利斯顿氏菌聚为一支。对48种抗生素的药敏结果显示,菌株33002对红霉素、阿奇霉素等25种药物敏感,对恩诺沙星、杆菌肽等22种药物不敏感。

A dominant bacterium nominated as 33002 was isolated from the kidney of diseased Plectropo- mus leolardus. It was strongly pathogenic to P. leopardus by artificial challenge. The bacterium was characterized according to its morphological, physiological and biochemical characteristics, and 16S rRNA and gyrB gene sequences. In phylogenetic tree based on gyrB gene, 33002 was clustered with L. anguil- larum. Antimicrobial susceptibility assay to 48 antimicrobial agents showed that 33002 was susceptible to 25 agents including erythromycin, azithromycin and florfenicol, but highly resistant to 22 agents including fnrofloxacin, bacitracin and furazolidone. These findings supported our identification of 33002 as a strain of Listonella anguillarum.