西伯利亚鲟(Acipenser baerii)致病性维氏气单胞菌的分离鉴定

摘要：【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16S rRNA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 veronii ATCC 35624T的16S rRNA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

Isolation and identification of pathogenic Aeromonas veronii isolated from infected Siberian sturgeon (Acipenser baerii)

Objective] Our study aimed at searching for the pathogenic factor causing Siberian sturgeon ( Acipenser baerii) disease .Methods] A pathogenetic bacterial strain X-1-06909 was isolated from naturally infected Siberian sturgeon in Beijing. The strain was identified according to its physiological and biochemical properties, and the sequence analysis of 16S rRNA gene. The drugs sensitivity was detected with Kirby-Bauer's agar diffusion method. Results] Based on the result of 16S rRNA sequence analysis, the strain X-1-06909 shares 99.6% sequence identity with the type strain ATTCC35624~T of Aeromonas veronii .The morphological characteristics of the strain were gram-negative, polar single-flagella.The results of physiological and biochemical tests were that the strain could ferment glucose and produce gas, methyl red ( M-R) and Voges-Proskauer ( V-P) tests were positive, arginine dihydrolase test was negative, it grew on 3% sodium chloride culture medium,the tests for hydrolysis of gelatin and hydrolysis of esculin were negative. The result for drug sensitive tests showed that among 21 antibiotics, cefadroxil, neomycin etc. Had better inhibitive effect on the strain. Conclusion] The isolated strain X-1-06909 was identified as A . Veronii . The results will provide evidences for further caring the diseases of sturgeons.