Bacterial strain JXHS was isolated from cultured yellow catfish Pelteobagrus fulvidraco infected with“cracked head disease” in Nanchang,Jiangxi Province.The strain was proved to be the pathogen of the disease in the challenging experiments by intraperitoneal injection .The isolated strain was identified as Ed-wardsiella ictaluri in morphology,physiology and biochemistry ,as well as 16S rRNA sequence.In addition,the bacterial strain JXHS was found to be highly sensitive to co-trimoxazole,norfloxacin,ciprofloxacin,butyl amine kanamycin and gentamicin ,but resistant to penicillin and cephalothin .%从江西南昌患“裂头病”黄颡鱼脑组织内分离到1株致病菌株，人工回归感染试验显示分离的菌株可使黄颡鱼发病死亡，证实分离菌株为养殖黄颡鱼“裂头病”的病原菌。对分离菌株（命名为JXHS）进行形态学、理化特性分析，初步判定所分离的菌株为爱德华氏菌，进一步对分离菌株的16S rRNA基因序列分析发现，JXHS的16S rRNA与GenBank中鮰爱德华氏菌（ Edwardsiella ictaluri）的相似性为99％。根据该分离菌株的16S rRNA基因序列采用MEGA 4．0软件构建分子系统发育树，发现分离菌株与鮰爱德华氏菌自然聚为一支，进一步证实该菌为鮰爱德华氏菌。药敏试验表明，该菌株对复方新诺明、诺氟沙星、环丙氟哌酸等5种药物高度敏感，而对青霉素、先锋霉素等不敏感。
展开▼
