SGER: Identifying Sources of Fecal Contamination and the Prevalence of Human Pathogens in Water, Sediments, and Shellfish of Lake Pontchartrain in Response to Floodwater Pumping

本项目是几个协调的海洋环境研究项目之一，该项目由探索性研究小额拨款（SGER）资助，用于快速响应自然灾害：卡特里娜飓风造成的新奥尔良洪水。夏威夷大学NSF-NIEHS海洋与人类健康中心（COHH）的科学家们的这项努力是与巴吞鲁日路易斯安那州立大学、迈阿密大学NSF-NIEHS海洋与人类健康中心和伍兹霍尔海洋研究所进行的一项更大规模合作研究的一部分。卡特里娜飓风在墨西哥湾沿岸地区登陆后不久，新奥尔良地区发生大范围洪水，导致污水溢出和洪水污染。此后不久，这些洪水未经处理就不断被泵入庞恰特雷恩湖，导致污染物扩散到湖中，最终排放到墨西哥湾。通过合作，这个多机构研究小组将调查庞恰特莱恩湖及附近水域被化学污染物、致病微生物和有害藻华（HAB）生物污染的程度。该研究将记录生物和非生物污染物以及有害藻华生物的水平和传播，这些信息将对后续的建模工作有用。在SGER的资助下，夏威夷大学的研究人员将在洪水抽取后的几周和几个月内，记录庞查特莱恩湖的水、沉积物和贝类中选定的人类病原体（弧菌、金黄色葡萄球菌、病毒）和污水指标（拟杆菌、FRNA噬菌体）的存在、丰度和命运。关于微生物病原体的数据将放在总体微生物群落丰度和多样性变化的背景下。这些数据将有助于区分来自污水和非污水传播的病原体的污染，并概述对湖泊微型浮游生物的生态影响。水和沉积物中的细菌病原体将在选择性培养基上作为菌落形成单位进行检测。利用磁珠技术从组织匀浆中进行物理富集后，对牡蛎中的病原体进行检测。获得的培养菌株的身份将通过生化试验进行验证，并通过选定的毒力相关基因的分子检测评估其相对致病性。荧光显微镜和分子指纹图谱将用于确定总微生物群落的丰度和组成。这项快速反应研究的主要广泛影响是，它将在自然灾害发生后提供急需的信息。污水释放的微生物可能会影响包括庞恰特雷恩湖在内的大片地区，随后会影响墨西哥湾。这两个地区的大量人口和渔业现在和将来都可能因接触这些化学物质、微生物和有害藻华菌而患上急性和慢性疾病。从基础科学和公共卫生的角度来看，重要的是调查这些污染物迁移的机制和程度。

ABSTRACTOCE-0554768This project is one of several coordinated marine environmental studies funded through a Small Grant for Exploratory Research (SGER) for rapid response to a natural disaster: the flooding of New Orleans by Hurricane Katrina. This effort by scientists at the NSF-NIEHS Center for Ocean and Human Health (COHH) at the University of Hawaii is part of a larger collaborative study with Louisiana State University at Baton Rouge, and with the NSF-NIEHS Centers for Oceans and Human Health at the University of Miami and the Woods Hole Oceanographic Institution. Shortly after Hurricane Katrina made landfall in the Gulf Coast Region, widespread flooding in the New Orleans area resulted in sewage overflows and contamination of floodwaters. Shortly thereafter, these floodwaters were pumped continuously into Lake Pontchartrain without treatment, resulting in the spread of contaminants into the Lake, which ultimately discharges towards the Gulf of Mexico. Working collaboratively, the multi-institutional research team will investigate the extent to which the waters in Lake Pontchartrain and vicinity have been contaminated with chemical contaminants, pathogenic microbes, and harmful algal bloom (HAB) organisms. The study will document the levels and spread of biotic and abiotic contaminants along with HAB organisms, information which will be useful for subsequent modeling efforts.With SGER funding through this award, investigators at the University of Hawaii will document the presence, abundance, and fate of selected human pathogens (Vibrio spp, Staphylococcus aureus, viruses) and sewage indicators (Bacteroides, FRNA coliphages) in water, sediments, and shellfish in Lake Pontchartrain in the weeks and months following floodwater pumping. Data on microbial pathogens will be placed in the context of changes in abundance and diversity of the total microbial community. The data will allow discrimination of contamination from sewage- vs. non-sewage-borne pathogens and an overview of the ecological impacts on the lake microplankton.Bacterial pathogens in water and sediments will be assayed as colony-forming units on selective media. Pathogens in oysters will be assayed following physical enrichment from tissue homogenates using magnetic bead technology. Identity of the cultivated strains obtained will be verified by biochemical tests and their relative pathogenicity assessed by molecular detection of selected virulence-associated genes. Epifluorescence microscopy and molecular fingerprinting will be used to determine the abundance and composition of the total microbial community.The primary broader impact of this rapid-response study is that it will provide much needed information in the aftermath of a natural disaster. The microbes released by the sewage can potentially impact a large area including Lake Pontchartrain, and subsequently the Gulf of Mexico. There are significant human populations and fisheries in both these areas that can experience acute and chronic disease from these chemical, microbial, and HAB organism exposures now and in the future. From a basic science and public health perspective, it is important to investigate the mechanisms by which and the extent to which these contaminants have migrated.