Halliday Elizabeth, McLellan Sandra L, Amaral-Zettler Linda A, Sogin Mitchell L, Gast Rebecca J
Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America.
School of Freshwater Sciences, Great Lakes Water Institute, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, United States of America.
PLoS One. 2014 Mar 5;9(3):e90815. doi: 10.1371/journal.pone.0090815. eCollection 2014.
Recreational water quality, as measured by culturable fecal indicator bacteria (FIB), may be influenced by persistent populations of these bacteria in local sands or wrack, in addition to varied fecal inputs from human and/or animal sources. In this study, pyrosequencing was used to generate short sequence tags of the 16S hypervariable region ribosomal DNA from shallow water samples and from sand samples collected at the high tide line and at the intertidal water line at sites with and without FIB exceedance events. These data were used to examine the sand and water bacterial communities to assess the similarity between samples, and to determine the impact of water quality exceedance events on the community composition. Sequences belonging to a group of bacteria previously identified as alternative fecal indicators were also analyzed in relationship to water quality violation events. We found that sand and water samples hosted distinctly different overall bacterial communities, and there was greater similarity in the community composition between coastal water samples from two distant sites. The dissimilarity between high tide and intertidal sand bacterial communities, although more similar to each other than to water, corresponded to greater tidal range between the samples. Within the group of alternative fecal indicators greater similarity was observed within sand and water from the same site, likely reflecting the anthropogenic contribution at each beach. This study supports the growing evidence that community-based molecular tools can be leveraged to identify the sources and potential impact of fecal pollution in the environment, and furthermore suggests that a more diverse bacterial community in beach sand and water may reflect a less contaminated site and better water quality.
通过可培养的粪便指示菌（FIB）来衡量的娱乐用水水质，除了受到来自人类和/或动物源的不同粪便输入的影响外，还可能受到当地沙子或海草中这些细菌的持续存在的影响。在本研究中，利用焦磷酸测序技术从浅水样本以及在有和没有FIB超标事件的地点的高潮线和潮间水线采集的沙子样本中生成16S高变区核糖体DNA的短序列标签。这些数据用于检查沙子和水的细菌群落，以评估样本之间的相似性，并确定水质超标事件对群落组成的影响。还分析了与先前被确定为替代粪便指示菌的一组细菌相关的序列与水质违规事件的关系。我们发现沙子和水样本拥有截然不同的总体细菌群落，并且来自两个遥远地点的沿海水样本之间的群落组成具有更大的相似性。高潮和潮间带沙子细菌群落之间的差异，尽管彼此之间比与水更相似，但与样本之间更大的潮差相对应。在替代粪便指示菌组中，在同一地点的沙子和水中观察到更大的相似性，这可能反映了每个海滩的人为贡献。这项研究支持了越来越多的证据，即基于群落的分子工具可用于识别环境中粪便污染的来源和潜在影响，此外还表明海滩沙子和水中更多样化的细菌群落可能反映污染程度较低的地点和更好的水质。
