鲫CyHV-2病毒病的诊断及组织病理损伤研究

Diagnosis and Histopathological Damage of CyHV-2 Virus Disease: A Case Study in Carassius auratus

【目的】为了确定一例鲫(Carassius auratus)鳃出血症的病原。【方法】无菌操作条件下从患病鱼的肝脏、脾脏等病原灶处分离病原菌;利用压片法取鳃丝、体表粘液进行观察,检查是否有寄生虫感染;取鳃、肝脏、脾脏、肾脏用聚合酶链式反应(PCR)技术检测鲤疱疹病毒Ⅱ型病毒(Cyprinid herpesvirus 2,CyHV-2),并构建系统发育树,结合组织病理学技术以分析鳃出血症的病因。【结果】结果发现,病鱼尾鳍末端发白,鳃丝出血、末端轻微溃烂,有少量红色腹水;寄生虫学检测未发现鳃丝和体表黏液有寄生虫寄生;通过微生物学诊断,未见病原菌生长;PCR检测结果显示患病鲫体内CyHV-2呈阳性;组织病理学检测表明,患病鲫的主要损伤靶器官为脾脏、鳃、肾脏、肠道、心脏和肝脏,主要引起重度鳃出血和坏死性鳃炎,重度坏死性脾炎、中度至重度肠炎、中度至重度坏死性肾炎、中度坏死性心肌炎和中度心内膜炎和轻度坏死性肝炎。【结论】推断本次鲫鳃出血症为CyHV-2感染导致。

【Objective】The aim of this study was to determine the pathogen of gills hemorrhagic disease of crucian carp.【Method】The pathogenic bacteria were isolated fromthe liver,spleen and other pathogenic sites of the diseased fish under the condition of sterile operation. The gill filaments and mucus on the body surface were taken by means of pressure film method for observation to check whether there was parasitic infection. Gill,liver,spleen,kidney with polymerase chain reaction (PCR) technology to detect Cyprinid herpesvirus2(CyHV-2),and construct phylogenetic tree analysis,combined with histopatho-logical techniques to the analysis of the gill disease causes.【Result】The results showed that the diseased fish tail fin turns white. The gill filament was bleeding and ulcerated,there was red ascites. Parasitological examination showed no parasitism in branchial filaments and mucus on the body surface. The growth of pathogenic bacteria was not detected by microbiological diagnosis. PCR results showed that CyHV-2 was positive in diseased fish. The results of the phylogenetic tree showed that the virus isolated in this experiment and CyHV-2 was the same. Histopathological results showed that the main target organs of crucian carp were gills,spleen,kidney,intestinal tract,heart and liver,resulting in different degrees of damage.【Conclusion】It could be inferred that the gills hemorrhage of crucian carp is a viral disease, which caused by CyHV-2.