Department of Global Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, United States of America.
Department of Global Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, United States of America.
Sci Total Environ. 2019 Feb 1;649:1514-1521. doi: 10.1016/j.scitotenv.2018.08.322. Epub 2018 Aug 27.
Fecal indicator bacteria (FIB) have been used to assess fecal contamination in recreational water. However, enteric viruses have been shown to be more persistent in the environment and resistant to wastewater treatment than bacteria. Recently, U.S Environmental Protection Agency has proposed the use of coliphages as viral indicators to better protect against viral waterborne outbreaks. This study aimed to detect and determine correlation between coliphages (F-specific and somatic), fecal indicator bacteria (enterococci and fecal coliforms), and human enteric viruses (human adenovirus) in a subtropical brackish estuarine lake. Water samples were collected from 9 estuarine recreation sites on Lake Pontchartrain in southeast Louisiana. Water samples (n = 222, collected weekly) were analyzed for coliphages and fecal indicator bacteria using culture-based methods and large volume water samples (n = 54, collected monthly) were analyzed for human adenovirus using quantitative PCR. Somatic coliphage and F-specific coliphage were found in 93.7 and 65.2% of samples with geometric mean concentrations of 30 and 3 plaque forming units (PFU) per 100 mL, respectively. Enterococci, fecal coliforms, and adenovirus were found in all samples with geometric mean concentrations of 27 most probable number (MPN), 77 MPN, and 3.0 × 10 gene copies per 100 mL, respectively. Watersheds in suburban areas exhibited significantly higher concentrations of coliphages and fecal indicator bacteria, indicating potential fecal contamination from septic systems. There was no significant correlation (p > 0.05) observed between the presence of adenoviruses and fecal indicator bacteria and coliphages. The presence of human adenovirus in Lake Pontchartrain poses a significant public health problem for both recreational use and seafood harvesting as it increases exposure risks. This study demonstrated the lack of relationship between fecal indicators and human viral pathogen in Lake Pontchartrain supporting an alternative microbial surveillance system such as direct pathogen detection.
粪便指示菌(FIB)已被用于评估娱乐水中的粪便污染。然而,肠病毒在环境中的持久性以及对废水处理的抵抗力都优于细菌。最近,美国环境保护署提议使用噬菌体作为病毒指标,以更好地防止病毒水源暴发。本研究旨在检测和确定亚热带咸水河口湖中噬菌体(F 噬菌体和肠道噬菌体)、粪便指示菌(肠球菌和粪便大肠菌群)和人类肠道病毒(人腺病毒)之间的相关性。从路易斯安那州东南部庞恰特雷恩湖的 9 个河口娱乐区采集水样。使用基于培养的方法分析水样中的噬菌体和粪便指示菌(n=222,每周采集一次),并使用定量 PCR 分析大体积水样(n=54,每月采集一次)中的人腺病毒。93.7%和 65.2%的水样中检出肠道噬菌体和 F 噬菌体,几何平均浓度分别为 30 和 3 噬菌斑形成单位(PFU)/100ml。所有水样中均检出肠球菌、粪便大肠菌群和腺病毒,几何平均浓度分别为 27 最可能数(MPN)、77 MPN 和 3.0×10 基因拷贝/100ml。郊区流域的噬菌体和粪便指示菌浓度明显较高,表明可能存在来自化粪池系统的粪便污染。腺病毒的存在与粪便指示菌和噬菌体之间未观察到显著相关性(p>0.05)。人腺病毒在庞恰特雷恩湖的存在对娱乐用水和海鲜捕捞都构成了重大公共卫生问题,因为它增加了暴露风险。本研究表明,在庞恰特雷恩湖中,粪便指标与人类病毒病原体之间缺乏关系,支持使用直接病原体检测等替代微生物监测系统。