黄金鲫温和气单胞菌鉴定及溶血素基因检测

采用常规的培养特征、理化特性及分子生物学的方法，从患病的黄金鲫体内分离到的优势菌YD-1进行了回感试验、表观生物学、药敏试验及毒力因子检测等系统性研究。结果表明，该菌在盐度1-3%、PH4-9，温度10-30℃的营养肉汤培养基中均能生长。该菌株16S rRNA基因序列（GenBank收录号: KC561935, 长度1446bp）和gyrB基因序列（GenBank收录号: KC561934, 长度1169bp）分别与其他气单胞菌属细菌的基因同源性相思似在97%-99%之间，构建系统发育树确定该菌株为温和气单胞菌(Aeromonas sobria)。人工回感试验可引起健康银鲫死亡。对该菌毒力因子进行检测，可扩增出溶血素基因片段。药敏试验显示：该菌对多粘菌素、头孢呋辛、米诺环素、复达新、菌必治、新霉素等6种药物敏感。

Isolation and Identification of Aeromonas sobria from Carassius auratus and Detection of hemolysin

A dominant bacteria strainYD-1 was isolated from liver of disease Carrassius auratus and its culture characteristics, morphological, main physiological and biochemical characteristics and the virulence factors were examined. It was confirmed that the strain salinity range was 1-3% , pH range was 4-9 and Suitable growth temperature range was from 4 to 9. Phylogenetic analysis of 16S rRNA and gyrB gene indicated high homogeneity between the isolate strain and Aeromonas sobria from GenBank database.The 16S rRNA gene fragment length was 1446bp(GeneBank Accession KC561935), the gyrB gene fragment length was 1169bp(GeneBank Accession KC561934). The results showed that the identified isolate belonged to Aeromonas sobria. Strong pathogenicity of the isolate strain (YD-1) to the Carrassius auratus. Hemolysin was the main virulence gene of Aeromonas sobria which could product toxins that was capable of causing death. And the hemolysin gene (1410bp) could be amplified by PCR. It was concluded that the isolated strain Aeromonas sobria carried hemolysin and provided an effective method for detecting of the Aeromonas sobria.The drug sensitive was tested for choosing the appropriate antibiotic and testing results by paper extension methods for drug sensitive showed that among 47 antibiotics, polymyxin, minocycline, neomycin, et al had the better inhibitive effects on the strain.