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【目的】本研究旨在寻找引起养殖西伯利亚鲟鱼(Acipenser baerii)病害的致病因子。【方法】从北京地区自然患病的西伯利亚鲟鱼体内分离到致病菌株X-1-06909,采用生理生化鉴定结合16SrRNA基因序列的系统发育学分析确定该菌株的系统发育地位。同时采用琼脂扩散法对抗菌类药物的敏感性进行测定。【结果】菌株X-1-06909与Aeromonas veroniiATCC35624T的16SrRNA基因序列相似性达99.6%;结合形态特征与生理生化测定结果,革兰氏阴性杆菌,具极生单鞭毛。发酵葡萄糖产酸,甲基红试验和乙酰甲基甲醇试验阳性,精氨酸双水解阴性,3%氯化钠生长,明胶水解阳性、七叶灵水解阳性等。在21种抗菌类药物对该菌的抑菌试验中,其中,头孢羟氨苄、新霉素等11种药物的抑菌效果较好。【结论】确定该菌株在分类上属于维氏气单胞菌(Aeromonas veronii)。为进一步防治鲟鱼养殖病害提供依据。
【Objective】 The aim of this study was to find out the pathogenic factors that cause the disease of Acipenser baerii. 【Method】 Pathogenic strain X-1-06909 was isolated from the naturally infected Siberian sturgeon in Beijing. The phylogenetic analysis was performed to determine the phylogenetic position of the strain by phylogenetic analysis using physiological and biochemical characteristics and 16S rRNA gene sequence. Agar diffusion method was also used to determine the sensitivity of antibacterials. 【Result】 The sequence similarity of 16S rRNA gene of strain X-1-06909 and Aeromonas veronii ATCC35624T was 99.6%. According to the morphological characteristics and physiological and biochemical determination results, Gram-negative bacilli had polar flagella. Fermented glucose acid, methyl red test and acetyl methyl methanol test positive, arginine double hydrolysation negative, 3% sodium chloride growth, positive gelatin hydrolysis, positive and other Ye Qiling hydrolysis. In the antibacterial test of 21 kinds of antibacterial drugs against this bacterium, 11 antibacterial effects of cefadroxil and neomycin were better. 【Conclusion】 The strain was identified as belonging to Aeromonas veronii. In order to provide a basis for further prevention and treatment of sturgeon breeding diseases.