Studies on infection cycles of newly emerging and re-emerging diseases of fishes

鱼类新发和再发疾病感染周期的研究

基本信息

批准号：
14206024
负责人：
OGAWA Kazuo
金额：
$ 28.2万
依托单位：
THE UNIVERSITY OF TOKYO
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14206024/
关键词：
emerging disease Neoheterobothrium birnavirus cold water disease white spot disease microsporidium wild fish cultured fish

项目摘要

1.Field investigation of the flounder birnavirus and VHSV among wild marine fishes showed that aquabirnavirus was isolated from horse mackerel, Japanese flounder and dark banded rockfish, and that VHSV was detected from Japanese flounder and sand lance. All isolates of VHSV except one belonged to Genogroup 3 (American genogroup). VHSV was easily transmitted by water-borne route from infected to uninfected fish, suggesting that the infection cycle completed between wild and cultured flounder.2.Occurrences of Neoheterobothrium hirame in 0-and 1-year-old Japanese flounder in Miyako Bay, Iwate Prefecture and Obama Bay, Fukui Prefecture were surveyed. In both areas, infection levels in both wild and released flounders were high in winter and low in summer and were several fold higher in Obama than in Miyako.3.Twenty three isolates of Flavobacterium psychrophilum, the causative bacterium of cold-water disease, were found in wild freshwater fishes (crucian carp, dace and ayu). We tried to apply the 5 isolates of bacteriolytic phages from ayu farms as biological control of cold-water disease.4.Sedimentation velocity and time required for the cyst formation of the protomont of Cryptocaryon irritans was determined. The determined values indicate that the parasite cyst is formed on the sea bed and the infection cycle of the parasite occurs between the sea bottom and the net-cage. Furthermore, it is suggested that the outbreak of the parasite is related to tide.5.Development of Kabatana takedai was suppressed by low temperature, but recurred by increase of temperature, suggesting that a release of latently infected fish results in spread of the disease. The unknown infective stage, ca. 40μm in size, was shown to originate in the dam located in an upper stream of the Chitose hatchery and invade fish perorally.

1.对野生鱼类中伯纳维病毒和VHSV地板的调查表明，从马鲭鱼，日本地板和深色带子鱼中隔离了Aquabirnavirus，并从日本地板和沙兰斯发现了VHSV。 VHSV的所有分离株都属于Genogroup 3（American Genogroup）。 VHSV很容易通过水传播路线从感染到未感染的鱼类传播，这表明在野生和培养地板之间完成了感染周期。2。Neoheterobothrium hirame在0和1岁的日本地板上在Miyyako Bay，Iwate Preftocation，Iwate Preftocation和Obama Bay，Fukui，Fukui，Fukui Preftucted进行了调查。在这两个地区，冬季的野外和释放地板的感染水平都很高，夏季的感染水平均高，在奥巴马中，在宫颈中的感染水平高。3.三十三个分离株在野生淡水鱼类（克里克斯carp，dace，dace，dace和ayyu）中发现了冷毛的灾难性细菌，即冷毛的灾难性细菌。我们试图将5种来自Ayu农场的细菌水解噬菌体应用于冷水疾病的生物控制。4。确定cryptocaryon Irritans原始囊肿的囊肿形成所需的水位速度和时间。确定的值表明寄生虫囊肿是在海床上形成的，寄生虫的感染周期发生在海底和净木板之间。此外，据建议，寄生虫的爆发与潮汐有关。5。Kabatana takedai的开发被低温抑制，但温度升高反映，这表明释放了潜在感染的鱼会导致疾病的传播。未知的感染阶段，大约。 40μm的尺寸显示出源自位于壳聚糖孵化场上流流的大坝，并对鱼类的侵袭。