摘要
为探明湖北荆州市某养殖基地患病黄颡鱼(Pelteobagrus fulvidraco)以烂身、腹水为主要症状且持续性死亡的确切病因,本研究对患病黄颡鱼进行了病原筛查,从患病黄颡鱼组织中分离到一株优势菌,经过形态特征、生理生化鉴定、16S rRNA测序和系统进化分析确定分离菌株为迟缓爱德华氏菌,命名为Et-4。结果显示:分离菌株Et-4具有较强的生物被膜形成能力,不携带esaV、fimA、gadB和katB四种主要的毒力基因。分离菌株Et-4人工感染健康黄颡鱼出现与自然发病类似的症状,并能从病鱼中再次分离出该菌,证实迟缓爱德华氏菌是引起此次黄颡鱼持续性死亡的致病原;分离菌株Et-4对黄颡鱼的LD_(50)为3.9×10^(6)CFU/g,结合毒力基因谱判定其为弱毒株。分离株Et-4携带耐药基因tet A、sulⅠ和add A1,对头孢类药物、庆大霉素、新霉素等敏感;对四环素类、青霉素类、万古菌素等耐药;中药抑菌实验表明乌梅和丁香对迟缓爱德华氏菌Et-4有明显的抑制效果。
The Pelteobagrus fulvidraco suffered persistent death with a rotten body and ascites as the main symptoms.The pathogen screening was carried out find out the exact cause of the disease of the P.fulvidraco in an aquaculture farm in Jingzhou city.A dominant strain was isolated from the diseased P.fulvidraco,and morphological characteristics,physiological and biochemical identification,16S rRNA sequencing and phylogenetic analysis confirmed that the isolated strain was Edwardsiella tarda,named E.tarda Et-4.E.tarda Et-4 had strong biofilm-forming ability and does not carry four major virulence genes esaV,fimA,gadB and katB.Artificial infection with E.tarda Et-4 caused P.fulvidraco to appear rotten body and ascites were similar to the clinical symptoms of natural onset,and the challenge bacteria could be isolated from the diseased fish tissues.The LD_(50) of Edwardella tarda Et-4 in P.fulvidraco was 3.9×10^(6) CFU/g,and it was judged to be a low virulent strain.The isolate E.tarda Et-4 carries the resistance genes tet A,sul I and add A1,and was sensitive to cephalosporins,gentamycin,neomycin and so on.It was resistant to 13 drugs,such as tetracyclines,penicillins vancomycin,etc.Chinese medicine Fructus mume and clove had an apparent inhibitory effect on E.tarda Et-4.
作者
靳洪振
王玲玲
吴亚鑫
彭康尧
袁汉文
雷连成
张付贤
JIN Hong-zhen;WANG Ling-ling;WU Ya-xin;PENG Kang-yao;YUAN Han-wen;LEI Lian-cheng;ZHANG Fu-xian(College of Animal Science,Yangtze University,Jingzhou 434023,Hubei,China;Engineering Research Center of Ecology and Agricultural Use of Wetland,Ministry of Education,Jingzhou 434023,Hubei,China;Key Laboratory of Waterlogging Disasters and Wetland Agriculture of Hubei Province,Jingzhou 434023,Hubei,China;College of Veterinary Medicine,Jilin University,Changchun 130062,China)
出处
《淡水渔业》
CSCD
北大核心
2023年第5期22-31,共10页
Freshwater Fisheries
基金
湖北省自然科学基金项目(2022CF314)
湖北省现代农业产业技术体系项目(HBHZD-ZB-2020-005)
湿地生态与农业利用教育部工程研究中心开放基金项目(KFT202003)。
