草鱼的一种急性细菌性传染病病原的分离鉴定及致病性研究  

IDENTIFICATION AND PATHOGENICITY OF BACTERIAL PATHOGENS ISOLATED IN AN OUTBREAK ON BACTERIAL DISEASE OF CTENOPHARYNGODON IDELLUS

作　　者：李楠[1] 郭慧芝[1] 焦冉[1] 张书环[1] 刘志新[1] 姚卫建[1] 聂品[1] 

机构地区：[1]中国科学院水生生物研究所,淡水生态与生物技术国家重点实验室,武汉430072

出　　处：《水生生物学报》2011年第6期980-987,共8页Acta Hydrobiologica Sinica

摘　　要：草鱼(Ctenopharyngodon idellus)的细菌性疾病是草鱼人工养殖过程中经常出现的疾病。文章对河南一草鱼养殖场2009年8月出现的暴发性细菌性传染病进行了研究。该渔场饲养的草鱼成鱼和鱼苗出现了体表溃烂、局部出血,肠系膜充血、出血,腹腔积水等症状,并大量死亡。从濒死草鱼的内脏中分离到3株细菌,经形态学、生理生化特性及16S rDNA序列分析,鉴定为霍乱弧菌(Vibrio cholerae)、嗜水气单胞菌(Aeromonas hydrophila)和柱状黄杆菌(Flavobacterium columnare)。其中,从患病鱼苗体内分离到霍乱弧菌;从成鱼分离到嗜水气单胞菌和柱状黄杆菌。回归试验证明3株细菌均能使草鱼致死,其中霍乱弧菌和嗜水气单胞菌对草鱼的半数致死量(LD50)分别是0.15×104 cfu/g和0.96×103 cfu/g。从草鱼中分离到致病性霍乱弧菌是首次报道。药敏试验表明,在所试的17种抗生素中,霍乱弧菌仅对利福平、左旋氧氟沙星、链霉素、奥复星、庆大霉素等5种抗生素敏感;嗜水气单胞菌仅对菌必治、奥复星、庆大霉素等3种抗生素敏感;而柱状黄杆菌则对其中的氨苄青霉素、利福平、左旋氧氟沙星等10种抗生素均敏感。The grass carp(Ctenopharyngodon idellus) is very important in aquaculture in China.However,the grass carp is often infected with bacterial diseases,resulting in huge economic losses in recent years.This paper reported an acute haemorrhagic disease of Ctenopharyngodon idellus in Henan Province,China.The typical symptoms of the dis-ease included decay of dorsal and caudal fins,congestion and hemorrhage in skin,muscle and intestine and ascites.The aim of this research was to isolate the pathogens of bacterial haemorrhagic disease in grass carp and to deter-mine their LD50 in grass carp,and also to identify the sensitivity to antibiotics.The pathogen were isolated from gill,liver,spleen,kidney and ascites of infected grass carps,respectively,and purified in Shieh medium and LB medium.The shape of bacteria was observed by either optical microscope or electronic microscopic.And the physiological and biochemical identification of the bacteria was performed on VITEK 2 automated microbiology system(Systems version: 0301,Mérieux).Besides,the sequences of 16S rRNA were amplified by PCR with universal primers and the sequences were analyzed by BLAST.Correspondingly,the phylogenetic trees were constructed by MEGA 4 based on the 16S rDNA sequences.To confirm the pathogenesis of the isolated strains,the artifial infection and half of lethal dose test were conducted in healthy grass carps.The result showed that three kinds of bacteria were isolated from the diseased grass carp with typical syndrome,and were named as F2,F4 and XF,respectively.The colonies of F2 and F4 were round,white and moist,while the colony of XF was rhizoid-like,yellow and dry.The result of optical microscopy showed that all the three strains were arc-rod and Gram-negative.There were flagellums on the polar of the F2 and F4 based on the result of electronic microscopy.The F2,F4 and XF pathogens were identified as Vibrio cholerae,Aeromonas hydrophila and Flavobacterium columnare,respectively,which based on the result of morphological observation,biochemical

关 键 词：草鱼 霍乱弧菌 嗜水气单胞菌 柱状黄杆菌 半数致死量 药敏试验 

分 类 号：S941.42[农业科学—水产养殖]