鱼源溶藻弧菌生物学特性和病理组织学观察

Biological characteristics and histopathological observation of Vibrio alginolyticus from diseased fish

摘要:

摘要:【目的】溃烂病是我国海水养殖及南方养殖斜带石斑鱼的常见严重病害之一。通过对患病的斜带石斑鱼病原菌的分离与鉴定，为检测其耐药性和控制石斑鱼在海水养殖中溃烂病的爆发和流行奠定基础。本文目的是研究斜带石斑鱼相关的病原菌的特性。【方法】从患病斜带石斑鱼肾脏、肝脏病灶组织，分离纯化得到病原菌，进行纯化培养、人工感染和回归感染、ATB细菌自动鉴定及药敏试验，并进行菌体常规形态特征、培养特性和生理生化反应指标测定。【结果】确定为溶藻弧菌(Vibrio alginolyticus)。两株典型菌株经人工感染和回归感染均显示自然发病症状。药敏试验表明，该菌具有较强的耐药性，在所检测的抗菌药物中，对青霉素等3类抗菌药物高度耐药，而对氯霉素等5类抗菌药物敏感。器官主要组织病理学变化为:肝细胞、肾小管细胞等变性、坏死，病变组织有炎性细胞浸润且呈变质性炎症。溶藻弧菌对机体的主要器官造成严重病理损伤。【结论】生理生化等结果均证实分离菌株是溶藻弧菌，而且产生多重耐药情况较为普遍，未来应加强对养殖海水中病原耐药性和斜带石斑鱼病原感染的监测。

Abstract:

Abstract:［Objective］Ulcer disease is one of the most serious diseases and a common problem in various stages marine culture including Epinephelus coioides culture of southern China．The isolation and identification of pathogenic bacteria from E.coioides will be useful for monitoring of drug resistance and controlling the outbreak and spread of ulcer disease in E.coioides．The purpose of this study was to characterize the pathogen of E.coioides．［Methods］ The pathogenic bacteria separated from the liver and kidney of diseased fish were identified through pure culture，artificial infection，automatic tests in bacteriology automatic identification，drug sensitive tests，morphometry，and physiological and biochemical determination.［Results］ The strains were characterized and identified as Vibrio alginolyticus． Two strain were selected for virulence tests and all the moribund/dead fish exhibited ulcer disease as that observed in natural outbreak．Drug sensitive tests show that V．alginolyticus was highly resistant to 3 agents including penicillin，whereas sensitive to 5 agents including chloromycetin．Histopathological changes were mainly shown as cell degeneration and necrosis of gill，liver and kidney，and alterative inflammation as a result of inflammatory cell infiltration in the diseased tissue．［Conclusion］ The biochemical，physiological tests confirm that V．alginolyticus is the pathogen causing E．coioides vibriosis．The multi-drug resistance among V．alginolyticus suggests strengthened monitoring of outbreaks of V．alginolyticus caused disease in E．coioides culture.