团头鲂病原嗜水气单胞菌的分离鉴定及药敏试验

Isolation,Identification and Drug Susceptibility of a Pathogenic Bacterial Strain from Bluntnose Black Bream Megalobrama amblycephala

从患病的团头鲂肝脏中分离到1株优势菌WJ-8。将菌株WJ-8进行人工回归感染试验,其患病症状同自然发病症状,证明其对团头鲂有致病性。该菌株的形态特征、主要理化特性、16SrRNA序列测定结果及系统发育树的构建表明该菌株为嗜水气单胞菌。药敏试验结果显示,该菌株对氟苯尼考、甲哌利福霉素、链霉素、卡那霉素等22种药物敏感,对青霉素、氨苄西林、羧苄青霉素、苯唑西林等12种药物表现出耐药性。

A dominant bacterium WJ-8 was isolated from hepatopancreas of diseased bluntnose black bream Megalobrama amblycephala.The challenge test by WJ-8 revealed that the prevalence of symptoms and spontaneous onset symptoms were as the same as the naturally infected bluntnose black bream,proving that WJ-8 was pathogenic to the bluntnose black bream.The morphological,physiological,and biochemical characteristics,and the construction of phylogenetic tree supported that the isolated strain was referred as Aeromonas hydrophila.The drug sensitive test by paper extension methods showed that florfenicol,Mepiquat,Rifamycin,streptomycin,kanamycin and other 22 kinds of drugs had the most inhibitive effects on the strain which showed resistance to penicillin,ampicillin,carbenicillin,oxacillin,and other 12 kinds of drugs.