斑点叉尾鮰套肠症的病原鉴定及其药敏特性  

Identification and antibiotic sensitivity of pathogen of intussusception disease found in channel catfish Ictalurus punctatus

作　　者：童桂香[1] 黎小正[1] 韦信贤[1] 吴祥庆[1] 卢小花[1] 

机构地区：[1]广西水产研究所,广西南宁530021

出　　处：《大连水产学院学报》2009年第6期475-481,共7页Journal of Dalian Fisheries University

基　　金：2009年广西壮族自治区直属公益性科研院所基本科研业务费专项资金资助项目(2060302GXIF-2009-05)

摘　　要：从患败血症并出现肠套叠的斑点叉尾鮰Ictalurus punctatus肝脏、肾脏及脑组织中分离到一株细菌(TE090214),经人工感染试验证实,该菌为斑点叉尾鮰病鱼的病原且具有高度致死性。对分离菌进行了形态特征、理化特性等较系统的表观分类学特征鉴定。结果表明:该菌经革兰氏染色为阴性,形状为两端钝圆的短杆菌,无荚膜及芽孢,氧化酶阳性,鸟氨酸脱羧酶阴性;能发酵葡萄糖产气,能利用甘露醇、蔗糖、阿拉伯糖和水杨苷产酸,能水解七叶苷等。对该菌的16S rDNA进行PCR扩增、克隆测序,得到1条长度为1 537 bp的核苷酸序列(GenBank登录号GQ184148);在以该菌16S rDNA序列和GenBank数据库内同源性较高的细菌16S rDNA序列构建的系统发育树中,菌株TE090214与嗜水气单胞菌Aeromonas hydrophi-la聚在一簇,结合形态及生理生化特点,可将该菌株鉴定为嗜水气单胞菌。药敏试验结果显示:在供试的15种抗菌药物中,菌株TE090214对头孢哌酮、卡那霉素、氧氟沙星、恩诺沙星、诺氟沙星敏感,对链霉素、阿米卡星、复方新诺明中度敏感,对氨苄青霉素等7种药物存在不同程度的耐药性。A strain bacterium （TE090214） isolated from the liver and brain of the diseased channel catfish lctalurus punctatus with haemorrhage symptom and ＂intussusception＂, was characteristically studied by morphological, physiological and biochemical and was proved to be the pathogen of the disease by artificial infection. The patho- genic bacterium was gram negative, rods in shape, non -capsule and gemma, oxidase -positive, orinithine decar- boxylase - negative, utilized mannitol, sucrose, arabinose and saliein with production of acid, and fermented glu- cose with production of gas and hydrolysis esculin. The 16S rDNA of strain TE090214 was amplified, cloned and sequenced, and a sequence of 1537 base pair （bp） was obtained from the bacteria （GenBank accession number GQ184148）. The phylogenetic tree constructed by comparing the 16S rDNA sequence of the isolated strain with other relative bacterial species from GenBank databases revealed that the strain TE090214, Aeromonas CCM 7232 and Aeromonas hydrophila ayu -Ah0201 constituted a branch. The isolated strain （TE090214） was i- dentified as Aeromonas hydrophila by morphological, physiological, biochemical characteristics and phylogenetic a- nalysis. The strain TE090214 was found to be sensitive to 5 agents including cefoperazone, intermediately sensitive to 3 agents including streptomycin, and resistant to 7 agents including ampicillin during antibiotic sensitivity to 15 antimicrobial agents.

关 键 词：斑点叉尾鮰 嗜水气单胞菌 套肠症 鉴定 药敏特性 

分 类 号：S941.42[农业科学—水产养殖]