青石斑幼鱼致病病原哈维氏弧菌的分离鉴定及致病性分析  

Identification and Pathogenicity Analysis of Vibrio harveyi from Juvenile Yellow Grouper(Epinephelus awoara)

作　　者：郭美玲 庞月 刘芯睿 刘玉茹 薛淑霞 孙金生[1,2] GUO Mei-ling;PANG Yue;LIU Xin-rui(College of Life Science,Tianjin Normal University,Tianjin 300387)

机构地区：[1]天津师范大学生命科学学院,天津300387 [2]天津师范大学/天津市动植物抗性重点实验室,天津300387

出　　处：《安徽农业科学》2023年第12期89-93,97,共6页Journal of Anhui Agricultural Sciences

基　　金：天津市海水养殖现代农业产业技术体系创新团队项目(ITTMR-S2022006);天津市劳模创新团队项目。

摘　　要：为阐明哈维氏弧菌对青石斑幼鱼的致病特性,开展了人工感染试验,注射感染健康青石斑幼鱼14 d,其半致死剂量(LD_(50))为6×10^(5) CFU/mL。毒力基因分析表明,该菌株携带鞭毛结构基因flaB、flaC,溶血素基因vhhA、vhhB,群体效应调节基因luxR和几丁质酶基因chiA 6个毒力基因。耐药性分析表明,菌株TJYG-42对甲硝唑(MTZ)、链霉素(S)、阿莫西林(AMX)和氨苄西林(AM)4种药物具有抗性。组织病理学分析表明,菌株TJYG-420感染引起了鱼体组织明显的病理变化,包括皮肤组织中囊状细胞数量明显增加,鳃细胞增生、肿胀、毛细血管扩张,肠黏膜断裂破损,部分绒毛脱落,肝脏细胞空泡化等。这些研究结果将为养殖青石斑鱼细菌性疾病的防治提供理论基础。In order to elucidate the pathogenic characteristics of the V.harveyi isolate on juvenile yellow grouper,we conducted artificial infection experiments using intraperitoneal injection and the LD_(50) was determined as 6×10^(5) CFU/mL in 14 days.The virulence gene analysis showed that the V.harveyi isolate carried 6 virulence genes,including flagellin(flaB、flaC),protease(chiA),hemolysin(vhhA、vhhB),population sensing system(luxR).Antibiotic susceptibility analysis showed that the V.harveyi isolate was susceptible to most antibiotics and resistant to only four drugs,including metronidazole(MTZ),streptomycin(S),amoxicillin(AMX)and ampicillin(AM).Histopathological analysis showed that the infection of the V.harveyi isolate caused obvious pathological changes in fish tissues,including more sacciform cells which cytoplasmic content formed an eosinophilic clump in the centre presented in skin tissues;cellular swelling vacuolation inflammatory infiltrating and angiotelectasis in gill lamellae;blunted,fused or shed intestinal villi and loosened mucous layer and connective tissues in intestine;cellular vacuolation in liver.The results suggest that the V.harveyi isolate is the causative pathogen causing massive mortalities in juvenile yellow grouper,carries a high number of virulence genes,is susceptible to most antibiotics,and its infection caused severe histopathological changes in the fish.These results of these studies will provide technical supports for the control of bacterial diseases in cultured yellow grouper.

关 键 词：青石斑鱼 哈维氏弧菌 耐药性 毒力基因 组织病理学评估 

分 类 号：S941[农业科学—水产养殖]