characterizing relationships among fecal indicator bacteria, microbial source tracking markers, and associated waterborne pathogen occurrence in stream water and sediments in a mixed land use watershed.
Characterizing relationships among fecal indicator bacteria, microbial source tracking markers, and associated waterborne pathogen occurrence in stream water and sediments in a mixed land use watershed.
机构信息
Oak Ridge Institute for Science and Education, P.O. Box 117, Oak Ridge, TN 37831, USA; Ecosystems Research Division, Office of Research and Development, National Exposure Research Laboratory, U.S. Environmental Protection Agency, 960 College Station RD, Athens, GA 30605, USA.
Ecosystems Research Division, Office of Research and Development, National Exposure Research Laboratory, U.S. Environmental Protection Agency, 960 College Station RD, Athens, GA 30605, USA.
出版信息
Water Res. 2016 Sep 15;101:498-509. doi: 10.1016/j.watres.2016.05.014. Epub 2016 May 13.
Bed sediments of streams and rivers may store high concentrations of fecal indicator bacteria (FIB) and pathogens. Due to resuspension events, these contaminants can be mobilized into the water column and affect overall water quality. Other bacterial indicators such as microbial source tracking (MST) markers, developed to determine potential sources of fecal contamination, can also be resuspended from bed sediments. The primary objective of this study was to predict occurrence of waterborne pathogens in water and streambed sediments using a simple statistical model that includes traditionally measured FIB, environmental parameters and source allocation, using MST markers as predictor variables. Synoptic sampling events were conducted during baseflow conditions downstream from agricultural (AG), forested (FORS), and wastewater pollution control plant (WPCP) land uses. Concentrations of FIB and MST markers were measured in water and sediments, along with occurrences of the enteric pathogens Campylobacter, Listeria and Salmonella, and the virulence gene that carries Shiga toxin, stx2. Pathogens were detected in water more often than in underlying sediments. Shiga toxin was significantly related to land use, with concentrations of the ruminant marker selected as an independent variable that could correctly classify 76% and 64% of observed Shiga toxin occurrences in water and sediment, respectively. FIB concentrations and water quality parameters were also selected as independent variables that correctly classified Shiga toxin occurrences in water and sediment (54%-87%), and Salmonella occurrences in water (96%). Relationships between pathogens and indicator variables were generally inconsistent and no single indicator adequately described occurrence of all pathogens. Because of inconsistent relationships between individual pathogens and FIB/MST markers, incorporating a combination of FIB, water quality measurements, and MST markers may be the best way to assess microbial water quality in mixed land use systems.
河流和溪流的底泥可能会储存高浓度的粪便指示菌（FIB）和病原体。由于再悬浮事件，这些污染物可能会被转移到水柱中，并影响整体水质。其他细菌指标，如微生物源追踪（MST）标记物，用于确定粪便污染的潜在来源，也可以从底泥中再悬浮。本研究的主要目的是使用简单的统计模型来预测饮用水和底泥中水源性病原体的发生情况，该模型包括传统测量的 FIB、环境参数和源分配，同时使用 MST 标记物作为预测变量。在农业（AG）、森林（FORS）和污水处理厂（WPCP）土地利用下游的基流条件下进行了同步采样。在水和沉积物中测量了 FIB 和 MST 标记物的浓度，以及肠道病原体弯曲杆菌、李斯特菌和沙门氏菌的出现情况，以及携带志贺毒素的毒力基因 stx2。病原体在水中的检出频率高于底泥。Shiga 毒素与土地利用显著相关，选择反刍动物标记物的浓度作为自变量，可以正确分类 76%和 64%的水中和底泥中观察到的 Shiga 毒素的出现。FIB 浓度和水质参数也被选为自变量，可以正确分类水中和底泥中的 Shiga 毒素（54%-87%），以及水中的沙门氏菌（96%）。病原体和指示变量之间的关系通常不一致，没有单一的指标可以充分描述所有病原体的出现情况。由于个体病原体与 FIB/MST 标记物之间的关系不一致，因此结合 FIB、水质测量和 MST 标记物可能是评估混合土地利用系统中微生物水质的最佳方法。
Zotero 插件