Effect of intertidal exposure on Vibrio parahaemolyticus levels in Pacific Northwest oysters
Effect of intertidal exposure on Vibrio parahaemolyticus levels in Pacific Northwest oysters
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DOI：
10.4315/0362-028x-67.10.2178
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发表时间：
2004-10-01
影响因子：
2
通讯作者：
DePaola, A
中科院分区：
文献类型：
--
作者：
Nordstrom, JL;Kaysner, CA;DePaola, A
在1997年和1998年美国西海岸和其他地区爆发副溶血性弧菌相关肠胃炎后，人们对副溶血性弧菌（Vp）的兴趣增加了。本研究评估了太平洋西北地区Vp生态学的多个方面，有三个目标：(i)确定低潮暴露对牡蛎Vp水平的影响，（ii）确定总Vp和致病性Vp之间的关系，（iii）检查沉积物和水生动物作为致病性Vp的储存库。样本是从华盛顿州胡德运河沿岸的潮间带珊瑚礁收集的。， 2001年8月。测试了海洋哺乳动物和水鸟的粪便以及底栖鱼类的肠道内容物。采用针对热稳定型直接溶血素（tlh）和热稳定型直接溶血素（tdh）基因的DNA探针集落杂交方法，对所有样品的总Vp和致病性Vp水平进行了计数。牡蛎中最大暴露时的平均Vp密度是相应首次暴露时的4至8倍。第一次暴露时，h- Vp阳性计数通常小于或等于10 CFU/g，而最大暴露时则高达160 CFU/g。在最大暴露条件下，沉积物中的Vp浓度与牡蛎中的Vp浓度无显著差异。42份最大暴露牡蛎样本中有9份（21%）检测到致病性（tdh阳性）Vp， 19份沉积物样本中有5份（26%）检测到致病性Vp，但9份排泄物样本中没有检测到致病性Vp。这些结果表明，夏季条件允许Vp在退潮暴露的牡蛎中繁殖。
Interest in Vibrio parahaemolyticus (Vp) increased in the United States following Vp-associated gastroenteritis outbreaks in 1997 and 1998 involving the West Coast and other areas. The present study evaluated multiple aspects of Vp ecology in the Pacific Northwest with three objectives: (i) to determine the effect of low-tide exposure on Vp levels in oysters, (ii) to determine the relationship between total and pathogenic Vp, and (iii) to examine sediments and aquatic fauna as reservoirs for pathogenic Vp. Samples were collected from intertidal reefs along Hood Canal, Wash., in August 2001. Fecal matter from marine mammals and aquatic birds as well as intestinal contents from bottom-dwelling fish were tested. Total and pathogenic Vp levels in all the samples were enumerated with colony hybridization procedures using DNA probes that targeted the thermolabile direct hemolysin (tlh) and thermostable direct hemolysin (tdh) genes, respectively. The mean Vp densities in oysters were four to eight times greater at maximum exposure than at the corresponding first exposure. While tdh-positive Vp counts were generally less than or equal to10 CFU/g at first exposure, counts as high as 160 CFU/g were found at maximum exposure. Vp concentrations in sediments were not significantly different from those in oysters at maximum exposure. Pathogenic (tdh positive) Vp was detected in 9 of 42 (21%) oyster samples at maximum exposure, in 5 of 19 (26%) sediment samples, but in 0 of 9 excreta samples. These results demonstrate that summer conditions permit the multiplication of Vp in oysters exposed by a receding tide.