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为了弄清鱼源嗜水气单胞菌(Aeromonas hydrophila)生理生化及药敏特性,试验采用细菌分离纯化和鉴定、16S rDNA分子测序、人工感染、药敏试验等方法对其进行了研究。结果表明:从患病鲫鱼肝脏中分离获得1株革兰氏阴性短杆菌,编号为CAH01,该菌能够利用葡萄糖、麦芽糖、海藻糖、甘露糖、蔗糖等多种碳源,与嗜水气单胞菌的理化特征相似性为0.596,遗传距离为5.924;测序获得16S rDNA长度为1 351 bp,与嗜水气单胞菌ATCC 7966标准菌株(登录号为X60404.2)序列相似性为99%,最终鉴定CAH01菌株为嗜水气单胞菌;人工感染试验表明,CAH01菌株对鲫鱼致死率为80%;药敏试验表明,对头孢氨苄、头孢克肟、头孢噻肟、萘啶酸、诺氟沙星、磺胺异唑、复方新诺明、呋喃妥因、庆大霉素、新霉素、氯霉素等抗生素敏感。说明鱼源CAH01菌株为致病性嗜水气单胞菌。
In order to understand the physiological, biochemical and antimicrobial susceptibility of Aeromonas hydrophila, the bacteria were purified and identified by bacterial isolation, 16S rDNA sequencing, artificial infection and susceptibility testing. The results showed that one strain of Gram-negative Brevibacterium, CAH01, was isolated from the liver of diseased crucian carp. The strain was able to utilize various carbon sources such as glucose, maltose, trehalose, mannose, sucrose, The similarity of physical and chemical characteristics of the bacteria was 0.596 and the genetic distance was 5.924. The length of 16S rDNA was 1 351 bp. The similarity to the sequence of Aeromonas hydrophila ATCC 7966 (accession number X60404.2) was 99% , The final identification of CAH01 strains of Aeromonas hydrophila; artificial infection test showed that CAH01 strains of carp mortality of 80%; drug susceptibility tests showed that cephalexin, cefixime, cefotaxime, nalidixic acid Ofloxacin, sulfisoxazole, cotrimoxazole, nitrofurantoin, gentamicin, neomycin, chloramphenicol and other antibiotics sensitive. The fish CAH01 strain is pathogenic Aeromonas hydrophila.