大菱鲆3种病原性红体病的流行性调查研究

The Epidemic Investigation of Turbot Reddish Body Disease Caused by Three Kinds of Pathogens

为分析大菱鲆红体病暴发的病原及红体病和养殖环境温度的相关性，于2011年3月-2012年1月的不同季节，在胶东半岛沿海多个养殖场收集大菱鲆红体病病鱼，采用光镜观察、弧菌选择性培养、电镜观察（负染和切片）、鱼类细胞病变效应（Cytopathic effect，CPE）检测以及PCR特异性扩增方法，观察其病理症状，分析、鉴定其致病病原。研究发现，所检各批次大菱鲆红体病鱼都不是寄生虫感染；环境温度较高时，一般为细菌性红体病（弧菌感染）；环境温度较低时，可检测到病毒性红体病，并发现有弧菌和病毒混合感染的病例；鳃丝是否灰暗贫血是区分细菌性红体病和病毒性红体病的最直接有效的鉴别病症。研究结果对于有效监控大菱鲆红体病的暴发，快速鉴别致病病原，实现对症治疗有重要意义。

Turbot reddish body disease refers to the occurrence of reddish skin along fin base and vertebra on the blind side of farmed turbot （Scophthalmus maximus）. It was reported that the causative pathogens of turbot reddish body syndrome （RBS） are diverse, which include bacteria, viruses and parasites, leading to a great challenge to the treatment of turbot RBS. In the present study, methods including light micro-scopic examination, selective cultivation of vibrio, electron microscopy observation （both negative staining and microtome section）, cytopathic effect （CPE） examination and the specific PCR were used to detect and analyze the pathogens responsible for turbot RBS. The diseased fish were collected from different farms along Jiaodong coastal area in different seasons between March 2011 and January 2012. The pathological symptoms were observed and the correlation among the outbreak of turbot reddish body disease, patho-gens and aquaculture ambient temperature were analyzed. We found that （1） all the turbot RBS were not caused by pathogenic parasites; （2） bacteria （i. e. vibrio） caused turbot RBS when the ambient tempera- ture was relatively high; and （3） either viruses or viruses and bacteria in combination caused turbot RBS when the ambient temperature was relatively low. Anemia of turbots and their grey gill filaments were the most obvious symptoms of bacterial turbot RBS, which was easily distinguishable from viruses turbot RBS. Our findings may aid to the effective monitoring of the outbreak of turbot reddish body disease, its rapid diagnosis and treatment and the healthy culture of turbot.