团头鲂细菌性败血症病原菌分离鉴定及致病力研究

Identification and Pathogenicity of Bacterial Pathogens Isolated in an Outbreak of Bacterial Disease of Bluntnose Black Bream,Megalobrama amblycephala

对江西省南昌县某水产养殖场出现的以"体表局部出血、溃疡,肠系膜充血、出血,腹腔内有大量积水"为主要症状的团头鲂细菌性败血症进行了研究。从病死及濒死团头鲂的病灶中分离到大量菌株,通过对其进行形态观察、生理生化特性鉴定、回归感染试验和药敏试验,结果将这些菌株鉴定为嗜水气单胞菌(Aeromonas hydrophila)和温和气单胞菌(Aeromonas sobria);2种致病菌均能导致团头鲂死亡,并出现与自然条件下相似的疾病症状;4个分离菌株对万古霉素、丁胺卡那、妥布霉素、卡那霉素、头孢拉定、头孢哌酮、先锋霉素V、氧哌嗪青霉素、氟哌酸等9种药物敏感;TTF-15菌株对先锋噻肟,TTF-004、TTF-013和TTF-015等3个菌株对头孢呋肟,TTF-013菌株对四环素处于中介敏感;而4个分离菌株对庆大霉素、头孢氨噻三嗪、复达欣和复方新诺明等4种药物显示耐药性。

This paper reported the fulminant haemorrhagic disease of bluntnose black bream（Megalobrama amblycephala）in Jiangxi,China.The typical symptoms of the disease included：decay in the end of dorsal and caudal fins;congestion and hemorrhage in skin;muscle and intestines with ascites.Two kinds of bacteria were isolated from the sick bluntnose black bream with typical syndrome and were proved to be its pathogen by artificial challenge.The pathogens were identified as Aeromonas hydrophila and Aeromonas sobria by morphological observation and biochemical test.The antibiotic sensitivity analysis showed that vancomycin,amikacin,tobramycin,kanamycin,cefradine,cefoperazone,cefazolin,piperacillin and norfloxacin were sensitive to Aeromonas hydrophila and Aeromonas sobria;A.hydrophila and A.sobria were resistant to gentamycin,ceftriaxone,ceftazidime and cotrimoxazole.