摘要
为探明昆明裂腹鱼(Schizothorax grahami)患"溃疡病"的致病原理,本研究在无菌条件下从患病昆明裂腹鱼体表溃烂处、肝脏与肾脏组织中分离、纯化病菌,采用形态学观察、生理生化特性鉴定及16S rDNA、dnaJ、cpn60等基因的序列分析进行细菌种类鉴定,通过回归感染确定其致病性,并以K-B纸片扩散法进行药敏试验。结果显示:自患病昆明裂腹鱼分离纯化获得形态大小均一的细菌菌落,随机选取肾脏分离细菌(BL61C)作为试验菌;形态学观察、生理生化特性鉴定及基因序列分析结果显示菌株BL61C为维氏气单胞菌(Aeromonas veronii);健康昆明裂腹鱼回归感染BL61C后的发病特征与自然病例一致,并从组织中再次分离到同种致病菌,表明维氏气单胞菌BL61C是引起本次昆明裂腹鱼溃疡病的致病菌,半数致死浓度(LC50)为5.09×107 CFU/mL;药敏试验结果表明分离菌对大观霉素、阿奇霉素、氧氟沙星、氯霉素、氟苯尼考、头孢他啶、头孢克肟和头孢噻肟等8种药物敏感,对克拉霉素、制霉菌素、四环素等20种药物耐药。
The bacteria were isolated and purified the pathogenic from body surface ulcers, liver and kidneys by bacterial isolation method under aseptic condition to clarify the pathogenic principle of Schizothorax grahami suffering from "canker disease".The pathogen was identified based on morphological observation, biochemical characteristics and sequence analysis of 16 S rDNA,dnaJ and cpn60.The pathogenicity of pathogenic bacteria was determined by artificial infection and the drug susceptibility was detected by Kirby-Bauer disk diffusion method.The results showed that the bacterial colonies with uniform morphology and size were isolated and purified from the diseased S.grahami.BL61 C was randomly selected as experimental bacteria.The results of morphological observation, identification of physiological and biochemical characteristics and sequence analysis of housekeeping genes showed that the pathogenic bacteria isolated was Aeromonas veronii.Artificial infected fish by intraperitoneal BL61 C injection showed the same symptoms as that of natural ones.The similar pathogenic bacteria were isolated from the tissue again, proving that A.veronii BL61 C was the pathogen causing epidermis ulcer of S.grahami,with the LC50 was 5.09×107 CFU/mL.Drug sensitivity test showed that the isolated bacterium was susceptible to eight kinds of antibiotics including spectinomycin, azithromycin, levofloxacin, chloramphenicol, florfenicol, ceftazidime, claforan and cefotaxime, while resistant to 20 drugs including claricid, cystatin and tetracycline.
作者
张桓桥
商宝娣
赵凤
周贤君
张效平
李小义
孔杰
杨星
陶莎
ZHANG Huan-qiao;SHANG Bao-di;ZHAO Feng;ZHOU Xian-jun;ZHANG Xiao-ping;LI Xiao-yi;KONG Jie;YANG Xing;TAO Sha(College of Animal Science,Guizhou University,Guiyang 550025,China;Guizhou fisheries Research Institute,Guiyang 550025,China;Guizhou Special Aquatic Products Engineering Technology Center,Guiyang 550025,China;Fisheries Technology Extension Center of Guiyang,Guiyang 550025,China)
出处
《淡水渔业》
CSCD
北大核心
2021年第6期54-62,共9页
Freshwater Fisheries
基金
国家自然科学基金地区基金项目(31560729)
国家特色淡水鱼产业技术体系贵阳综合试验站(CARS-46)
贵州省特色水产现代农业产业技术体系疾病防控功能实验室(GZCYTX2019-01102)
省科技厅科研机构服务企业项目(黔科合平台人才[2016]5714)
贵州省农业科学院青年基金(黔农科院青年基金[2018]51号)。
