嗜水气单胞菌在浸泡感染团头鲂的组织动态分布  

Infection kinetics of Aeromonas hydrophila in the blunt-snout bream, Megalobrama amblycephala

作　　者：陆春云[1,2] 谢骏[1,2] 习丙文[2] 梁利国[2] 夏飞[2] 潘良坤[2] 

机构地区：[1]南京农业大学无锡渔业学院,江苏无锡214081 [2]中国水产科学研究院淡水渔业研究中心、农业部淡水渔业和种质资源利用重点实验室,江苏无锡214081

出　　处：《中国水产科学》2015年第5期1068-1074,共7页Journal of Fishery Sciences of China

基　　金：现代农业产业技术体系建设专项资金项目(CARS-46-10)

摘　　要：利用具有绿色荧光蛋白基因标记的嗜水气单胞菌(WJ-8G FP)对团头鲂(Megalobrama amblycephala)进行浸泡攻毒试验,探究温度对浸泡感染后嗜水气单胞菌在团头鲂各组织分布的影响。实验设立A组(水温25℃),B组(水温32℃),C组(水温25℃),其中C组为对照组。用菌株WJ-8G FP对实验组A、B进行浸泡攻毒,试验组C不进行攻毒处理,攻毒后分别于2 h、4 h、8 h、12 h、24 h采集各组鱼血液、脾、肾、鳃、肠道、肌肉,培养法统计分析各组织器官上的荧光细菌数量。实验结果显示,在各取样时间段实验组A(25℃)和实验组B(32℃)团头鲂各组织在均能检测到荧光嗜水气单胞菌,对照组未检测到嗜水气单胞菌;最高菌量出现在鳃,且鳃上嗜水气单胞菌数量显著大于其他组织(P<0.05),其次是脾、肾;组织内的菌量随时间大体呈现先上升后下降的趋势;B实验组中各组织菌量显著大于A实验组(P<0.05)。研究结果表明,鳃是嗜水气单胞菌浸泡感染团头鲂的主要组织器官,与25℃相比较,在水温32℃时团头鲂被嗜水气单胞菌感染的风险更高。Fish disease has become an increasingly prominent problem in aquaculture development and causes severe economic damage to fisheries. Aeromonas hydrophila is an important fish pathogen that causes hemor-rhaging and septicemia in many cultured fishes. The infection kinetics of A. hydrophila in blunt-snout bream Megalobrama amblycephala were investigated with a strain, A. hydrophila WJ-8, that was transformed with a plasmid encoding green fluorescent protein （pEGFPuv-Kar）. The purpose of this investigation was to fully eluci-date the pathogenesis of septicemia in blunt-snout bream and provide basic data on pathogenic factors of A. hy-drophila. Fish were divided into three experimental groups： group A, water temperature 25℃; group B, water temperature 32℃;and group C （control group）, water temperature 25℃. Fish were allowed to acclimatize for two weeks before experiment proceeded. Aeromonas hydrophila WJ-8GFP was cultured in LB medium that contained kamamycin （60μg/mL） at 27℃for 24 h, and bacteria was counted and then transferred to a fish culture tank at a final concentration of 105 CFU/mL. The bacteria bath challenge was maintained for 30 min for groups A and B but not for group C. Then, fish were transferred to tanks with clean water and the original water temperature was maintained. The bacterial counts from the blood, spleen, kidney, gills, intestine, and muscle were detected at 2 h, 4 h, 8 h, 12 h, and 24 h after challenge. Bacteria were detected in both infected groups （A and B） but not in the un-infected control group （C） at all times during the experiment. An increased number of bacteria was observed in the gills of fish in groups A and B （P〈0.05）, whereas large numbers of bacteria were also noted in the spleen, kidney, and intestine. There were more bacteria that attached to and proliferated on the fish gills at 32℃ than 25℃. The bacterial counts for group B were significantly higher than those of groups A and C （P〈0.05）. These results indi-cate that the gill s

关 键 词：嗜水气单胞菌 浸泡感染 绿色荧光蛋白 团头鲂 组织分布 

分 类 号：S941[农业科学—水产养殖]