黄颡鱼源迟缓爱德华氏菌的分离鉴定及其药物敏感性研究  

Isolation,identification and drug sensitivity of Edwardsiella tarda from Pelteobagrus fulvidraco

作　　者：高宣 阳龙江 李小甜 刘丹[1] 何语奇 吕光俊[1] 王相煊 何钊林 朱成科[1] GAO Xuan;YANG Longjiang;LI Xiaotian;LIU Dan;HE Yuqi;LYU Guangjun;WANG Xiangxuan;HE Zhaolin;ZHU Chengke(College of Fisheries,Southwest University/Key Laboratory of Freshwater Fish Resources and Reproductive Development,Ministry of Education,Chongqing 402460,China;Sichuan Datang International Ganzi Hydropower Development Co.,Ltd.,Kangding 626001,China)

机构地区：[1]西南大学水产学院/淡水鱼类资源与生殖发育教育部重点实验室,重庆402460 [2]四川大唐国际甘孜水电开发有限公司,四川康定626001

出　　处：《南方水产科学》2024年第6期155-168,共14页South China Fisheries Science

基　　金：重庆市水产科技创新重点攻关项目(4322200160);重庆市技术创新与应用发展项目(cstc2020jscx-lyjsAX0011)。

摘　　要：为确定重庆市荣昌区某养殖场黄颡鱼(Pelteobagrus fulvidraco)疾病爆发的原因,从患病黄颡鱼肝脏中分离到一株优势菌,命名为ET230818。通过形态学观察、生理生化鉴定和16S rRNA、gyrB、rpoB、cpn60基因序列分析确定ET230818为迟缓爱德华氏菌(Edwardsiella tarda)。通过人工感染试验计算出菌株ET230818对黄颡鱼[平均体质量(17.5±2.5)g、平均体长(15.0±1.2)cm]的半数致死量(LD50)为2.51×10^(6)CFU·mL^(-1)。毒力基因检测结果显示,该菌株携带sodB、katB、esrB、gadB、fimA、citC和mukF毒力基因。组织病理学观察发现,患病黄颡鱼肝细胞排列杂乱、肿胀,脾组织中含血铁黄素聚集,肾小管收缩变窄且结构松散、萎缩;肠道黏膜细胞排列杂乱、坏死脱落,肠绒毛崩解,鳃小片明显变性弯折。抗菌药物敏感性试验与中草药抑菌试验发现,菌株ET230818对多西环素、恩诺沙星等11种抗菌药物高度敏感,丁香、五倍子等中草药对其具有较强的抑菌效果,研究可为黄颡鱼源迟缓爱德华氏菌的诊断和药物防治提供参考依据。To determine the cause of Pelteobagrus fulvidraco's disease outbreak on a breeding farm in Rongchang,Chongqing,we isolated a dominant bacterium from the liver of diseased fish and named it as ET230818.Based on morphological observation,physiological and biochemical identification and through the analysis of 16S rRNA,gyrB,rpoB and cpn60 gene sequences,we confirmed ET230818 as Edwardsiella tarda.The artificial infection experiment finds out the median lethal dose(LD50)of strain ET230818 to P.fulvidraco[Average body mass of(17.5±2.5)g,average body length of(15.0±1.2)cm]was 2.51×10^(6)CFU·mL^(-1).Virulence gene test results show that the strain carried sodB,katB,esrB,gadB,fimA,citC and mukF virulence genes.Histopathological observation reveals that the infected P.fulvidraco had disordered and swollen hepatocytes,with hemosiderin concentration in spleen tissue;the renal tubules contracted and narrowed,and the structure of the renal tubules became loose and atrophied;the arrangement of intestinal mucosal cells was disorderly,necrotic and shedding;the intestinal villi disintegrated;and the branchial lamella was obviously deformed and bent.The antimicrobial susceptibility test and Chinese herbal antibacterial experi-ment show that strain ET230818 was highly sensitive to 11 western medicines such as Doxycycline and Enrofloxacin,and Chinese herbs like Syzygium aromaticum and Galla chinensis had strong bacteriostatic effects on E.tarda.This study can provide references for the diagnosis and drug control of E.tarda from P.fulvidraco.

关 键 词：黄颡鱼 迟缓爱德华氏菌 鉴定 毒力基因 药物敏感 

分 类 号：S941.42[农业科学—水产养殖]