鳗鲡病原性维氏气单胞菌的分离与鉴定

从养殖患病的日本鳗鲡(Anguilla japonica)肾脏分离得到1株优势菌株,形态特征和生理生化测试结果显示,分离菌在4%羊血平板培养基上呈α型溶血,革兰氏阴性,有运动性,氧化酶阳性,在pH6.0和1%NaCl中生长等。结合Biolog自动微生物鉴定系统和16S rRNA、gyrB基因序列分析结果,确定该分离菌为维氏气单胞菌(Aeromonas veronii)。人工腹腔注射感染鳗鲡的试验结果表明,分离菌对鳗鲡的半数致死量LD50为2.15×107CFU/mL。药敏试验结果显示,在13种抗菌类药物中,分离菌对左氧氟沙星、氟哌酸、阿奇霉素和萘啶酸等8种药物敏感,而对利福平和新生霉素等5种药物敏感度低。

Isolation and Identification of Pathogenic Aeromonas veronii from Anguilla japonica

A dominant bacterial strain was isolated from the kidney of a diseased Anguilla japonica.Morphological,physiological and biochemical tests showed that the strain were α-hemolytic in 4% sheep blood plate,gram-negative,motile,oxidase-positive,grew at 1% NaCl and pH6.0 medium.By combinative use of Biolog identification,16S rRNA and gyrB gene sequence analysis,the strain was identified as Aeromonas veronii.The strain was proved to be a pathogen by intraperitoneal injection with bacteria suspension.The LD50 was 2.15×107 CFU/mL.The drug sensitivity test of 13 antimicrobial agents showed that the strain were highly sensitive to 8 agents such as levofloxacin,norfloxacin,azithromycin and nalidixic acid,and so on,but showed low sensitivity to the penicillin,rifampin,trimethoprim,sulfamethoxazole and novobiocin.The present study provides references to the prevention and treatment of disease caused by this strain.