大菱鲆源杀鱼爱德华氏菌(Edwardsiella piscicida)的分离鉴定

从患腹水病大菱鲆Scophthalmus maximus的肝脏中分离到一株优势细菌G1,经人工感染实验表明G1为引发大菱鲆腹水病的致病菌,且半致死浓度为LD50=1.21×105 CFU·g-1。采用常规的生理生化鉴定方法及分子生物学方法对G1进行分析,结果表明,G1的16SrRNA基因序列与杀鱼爱德华氏菌Edwardsiella piscicida的同源性达100%,系统发育分析表明菌株G1与杀鱼爱德华氏菌分支聚为一支,结合生理生化鉴定结果确定G1为杀鱼爱德华氏菌。药敏试验表明菌株G1对头孢曲松、环丙氟哌酸、左氧氟沙星等8种抗菌药物高度敏感。

Isolation and identification of Edwardsiella piscicida from turbot Scophthalmus maximus

Strain G1 was isolated from the turbot Scophthalmus maximus with ascites disease.The regression experimental infection showed that G1 was the pathogen causing ascites disease of Scophthalmus maximus,and its median lethal dose(LD 50)to Scophthalmus maximus was 1.21×10^5 CFU·g^-1.G1 was identified by conventional physiological and biochemical methods and 16S rRNA alignment.The results showed that 16S rRNA sequences of G1 exhibited 100%homology with Edwardsiella piscicida.Phylogenetic trees of 16S rRNA showed that the strain G1 and E.piscicida clustered into one branch.Strain G1 was identified as E.piscicida combined with physiological and biochemical methods.The susceptibility test showed G1 was sensitive to ten antibiotics,including florfenicol,ofloxacin,etc.