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Epidemiological studies on the mechanism for persistence of Vibrio parahaemolyticus in some estuarine gastropods

部分河口腹足动物副溶血性弧菌持续存在机制的流行病学研究

基本信息

批准号：
59480088
负责人：
KATO Eiichi
金额：
$ 4.61万
依托单位：
Tottori University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1984
资助国家：
日本
起止时间：
1984 至 1986
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-59480088/
关键词：
Vibrio parahaemolyticus gastropod mollusc Clithon retropictus イシマキガイ定着

项目摘要

Vibrio parahaemolyticus was observed to overwinter in sediments and to be present in considerable number in sediments and a gastropod mollusc, Clithon retropictus, during summer months at Hashizu estuary in Tottori Prefecture. The highest level of the organism was 9.3 x <10^4> and 2.3 x <10^5> cfu/g in sediments and C. retropictus respectively. Production of Kanagawa hemolysin was detected in about 12 and 20% of strains isolated from sediments and C. retropictus respectively at 2 stations in the estuary but not detected at the other 3 stations. Levels of the organism in 20 molluscs varied between <10^3> to zero cfu per mollusc at the estuary even in summer. The organism was also detected from microalgal populations at the estuary in summer, in which the highest was 1.4 x <10^5> cfu/g.C. retropictus ingested V. parahaemolyticus strain D-3(Kanagawa positive; nal-r) or R-13(Kanagawa negative; rif-r) of Escherichia coli strain YS-2(nal-r) was held in aquariums with 28 liters of artificial seawater with salinities of 8.8 to 25 permil at 25゜C for 21 days. Every 5 molluscs were sacrificed at appropriate intervals to obtain homogenates of soft tissues for viable counts of the organisms. V. parahaemolyticus strain D-3 was detected for 21 days in levels of <10^3> to <10^5> cfu/g from the mollusc held in the artificial seawater with salinity of 15 or 20 permil. When the mollusc ingested strains D-3 and R-13 was held in 15 permil water, these strains were detected in similar levels to those ingested each strain, in which any conversion on their productivity of Kanagawa hemolysin as well as pathological changes were not observed. E. coli strain YS-2, though it was ingested in level of <10^6> cfu/g, decreased to <10^3> cfu/g within 4 days and preserved the level afterward in those held in any salinity.

在鸟取县桥州河口，夏季观察到副溶血性弧菌在沉积物中越冬，并在沉积物和腹足类软体动物中大量存在。在沉积物和C. retropictus中的最高水平分别为9.3 x <10^4>和2.3 x <10^5> cfu/g。在河口2个站点的沉积物分离菌和C. retropictus分离菌中分别检测到12%和20%的神奈川溶血素，而在其他3个站点未检测到神奈川溶血素。即使在夏季，20种软体动物体内的微生物水平也在每只软体动物<10^3 cfu至0 cfu之间变化。夏季在河口微藻种群中也检测到该生物，最高为1.4 x <10^5> cfu/g.C。将食入副溶血性弧菌菌株D-3（神奈川阳性；nal-r）或大肠杆菌菌株s -2（nal-r）的R-13（神奈川阴性；rif-r）饲养于水族箱中，水族箱中有28升盐度为8.8 - 25 peril、25ºC的人工海水，饲养21天。每5只软体动物在适当的时间间隔被处死，以获得软组织匀浆进行生物活菌计数。在盐度为15或20 peril的人工海水中，从软体动物中检测到副溶血性弧菌D-3，持续21天，浓度<10^3> ~ <10^5> cfu/g。将摄入菌株D-3和R-13的软体动物置于15 permil的水中，检测到这些菌株的水平与摄入菌株的水平相似，其中神奈川溶血素的生产力没有任何转化，也没有观察到病理变化。大肠杆菌菌株YS-2的摄食水平虽然低于10^6> cfu/g，但在4天内下降到<10^3> cfu/g，并在任何盐度下保持该水平。