大口黑鲈致死性结节病病原的分离、鉴定及组织病理学观察  

Isolation, identification and histopathological study on lethal sarcoidosis of Micropterus salmoides

作　　者：何晟毓 魏文燕[3] 刘韬[1] 杨倩[1] 谢恒 何琦瑶 汪开毓[1,2] HE Shengyu;WEI Wenyan;LIU Tao;YANG Qian;XIE Heng;HE Qiyao;WANG Kaiyu(Fisheries Department of Sichuan Agricultural University,Chengdu 611130,China;Key Laboratory of Animal Disease and Human Health of Sichuan Province,Sichuan Agricultural University,Chengdu 611130,China;Institute of Fisheries,Chengdu Academy of Agricultural and Forestry Sciences,Chengdu 610000,China)

机构地区：[1]四川农业大学鱼病研究中心,四川成都611130 [2]四川农业大学动物疫病与人类健康四川省重点实验室,四川成都611130 [3]成都市农林科学院水产研究所,四川成都610000

出　　处：《水产学报》2020年第2期253-265,共13页Journal of Fisheries of China

基　　金：教育部“长江学者和创新团队发展计划”创新团队项目(IRT0848);成都市农林科学院科研创新项目(2017-Y2500W-16)~~

摘　　要：2018年4月四川邛崃地区某养殖场大口黑鲈感染致死性结节病,死亡率高达80%。为明确病因,通过常规微生物分离、鉴定,从患病鱼皮肤溃疡灶、鱼鳔腔积液和肝脏组织中分离到同一株优势菌,命名为HSY-NS02。经菌体形态观察、革兰氏染色和抗酸染色镜检、生理生化实验、16S rDNA序列扩增及系统发育分析和特异性PCR扩增,确定该菌为诺卡氏菌。进一步对健康大口黑鲈进行分离菌的人工感染实验以确定其致病性,结果显示,人工感染鱼出现与自然发病相似症状,且从人工感染鱼体中再次分离到相同菌。组织病理学观察显示,皮肤溃疡灶、心脏、肝脏、脾脏、肾脏和鳃发生不同程度的慢性炎性肉芽肿病变,其中脾脏病变最为严重。对菌株HSY-NS02进行药物敏感性实验,结果显示,该菌对庆大霉素、新霉素和制霉菌素3种药物敏感,对其他18种药物耐受,呈多重耐药性。In April 2018,a large number of largemouth bass(Micropterus salmoides)were infected with lethal sarcoidosis in a farm in Qionglai,Sichuan Province.In order to define the potential pathogens,a bacterial strain named HSY-NS02 was isolated from skin ulcers,effusions from fish swimming bladder’s cavity and liver of the diseased M.salmoides by traditional pathogen isolation methods.The strain HSY-NS02 was identified as Nocardia seriolea by means of morphologic structure and staining observation,PCR amplification and sequence analysis of 16S rRNA gene and specific primer,constructing phylogenetic tree,physiological and biochemical test.Furthermore,the pathogenicity of the strain HSY-NS02 was confirmed by the infection experiment in healthy M.salmoides.The results showed that the strain HSY-NS02 was cofirmed to be pathogenic to healthy M.salmoides and the same bacterium could be recovered from these infected M.salmoides.Histopathological observation and analysis of diseased M.salmoides showed that there were different degrees of chronic granulomatous lesions in skin ulcers,heart,liver,spleen,kidney and gill,of which spleen lesions were the most serious.The antibiotic susceptibility of the strain HSY-NS02 was carried out to guide clinically choosing medicine,and the results showed that the strain was sensitive to gentamicin,neomycin and nystatin,but resistant to other 18 kinds of antibiotics,which implied the strain HSY-NS02 was resistant to multiple antibiotics.

关 键 词：大口黑鲈 诺卡氏菌 分离 鉴定 组织病理学 

分 类 号：S941.42[农业科学—水产养殖]