Study on the Pathogen of the Fulminant Infectious Disease in the Fry ofEpinephelus lanceolatus in Southern Fujian
- 海洋环境－已发表论文 
应用RT PCR技术,检测了福建南部石斑鱼育苗场患病紫石斑鱼的病原,结果检出神经坏死病毒;对该病毒的RT PCR产物进行了核酸测序和序列分析,与基因库中马拉巴斑和紫石斑神经坏死病毒编码病毒核衣壳蛋白的基因片段序列的同源性大于97%.病原菌分离鉴定结果,有2菌株分别是溶藻弧菌和豚鼠气单胞菌,对实验动物有一定的毒力.药敏试验表明这些菌株对常用抗生素表现耐药.临床症状和实验结果都表明,神经坏死病毒感染是导致石斑鱼大批死亡的主要原因,而溶藻弧菌和豚鼠气单胞菌应为继发感染,加重了病情,使更多的石斑鱼死亡.In recent years, some cultured fry of grouperEpinephelus lanceolatus in southern Fujian Province, China had suffered an epidemical disease which caused heavy mortality. The average death rate was as high as 60 to 80 percent. The sick or died groupers did not show any patholgical signs other than neurological abnormalities in the early time of the disease, no significant external or intermal lesions or parasites were observed. An initial study was taken on the pathogen infected by the fishes. The reverse transcription polymerase chain reaction (RT-PCR) was used to detect nervous necrosis virus. It was found that the juvenile grouper had been infected with nervous necrosis virus. The fragment of 421bp of NNV was amplified and sequenced. It showed more than 97 percent homologue with the sequences of other NNV strains from grouper in Gene Bank. This result also indicated that the amplified sequence was the conservative area of the gene in NNV.Two strain of pathogen asVibrio alginolyticus andAeromonas caviae were separated from the sick grouper. These germs had virulence to the experimental animal and did not sensitive to most antibiotics. All of the clinic symptoms and examinations indicated that the NNV was the major cause of the disease and the second-infection ofV. alginolyticus andA. caviae had high morbidity and more mortality from the infection in these fries.