微翅目
生物
鲈鱼(鱼)
诺卡菌病
微生物学
维罗尼气单胞菌
病理
诺卡迪亚
气单胞菌
渔业
细菌
遗传学
医学
作者
Xun Lei,Rui Zhao,Yun Geng,Kai Wang,Ping Yang,Dongwei Chen,Xiao Huang,Zhicai Zuo,Quan‐Bin Han,Zhen Chen,Chao Huang,Hongbo Guo,Lai Wen
出处
期刊:Diseases of Aquatic Organisms
[Inter-Research Science Center]
日期:2020-08-04
卷期号:142: 13-21
被引量:34
摘要
Nocardia seriolae is the causative agent of nocardiosis in both marine and freshwater fish. Here, we report on multiple outbreaks of nocardiosis associated with elevated mortality (23-35%) in farmed largemouth bass in Sichuan, China, from 2017 to 2018. A total of 9 strains isolated from diseased largemouth bass were identified as N. seriolae by phenotypic characterization, 16S rRNA and hsp65 gene sequence analysis. The clinical signs of infected largemouth bass included hemorrhage, skin ulcers and prominent tubercles varying in size in the gill, liver, spleen and kidney. Experimental infection indicated that these isolates were the pathogens responsible for the mortalities. In vitro antibacterial activities of 12 antibiotics against N. seriolae isolates were determined as minimum inhibitory concentrations. Histopathological observation of diseased fish infected with N. seriolae showed necrotizing granulomatous hepatitis, nephritis, splenitis, epithelial hypertrophy and hyperplasia with degenerative changes of the epithelium in the gill. Large quantities of bacterial aggregates were found in the necrotic area of the granuloma by Lillie-Twort Gram stain and immunocytochemistry. Our findings indicated that N. seriolae is a serious threat to the largemouth bass Micropterus salmoides industry in Southwest China.
科研通智能强力驱动
Strongly Powered by AbleSci AI