BioTechnology Institute, University of Minnesota, 1479 Gortner Ave, St. Paul, MN 55108, USA.
Department of Integrative Biology, SCA 110, University of South Florida, 4202 East Fowler Ave, Tampa, FL 33620, USA.
Environ Int. 2019 Sep;130:104703. doi: 10.1016/j.envint.2019.03.051. Epub 2019 Jul 8.
The use of microbial source tracking (MST) marker genes has grown in recent years due to the need to attribute point and non-point fecal contamination to specific sources. Quantitative microbial risk assessment (QMRA) is a modeling approach used to estimate health risks from exposure to feces-contaminated water and associated pathogens. A combination of these approaches [quantitative MST (qMST) and QMRA] can provide additional pathogen-related information for prioritizing and addressing health risks, compared to reliance on conventional fecal indicator bacteria (FIB). To inform expansion of this approach, a review of published qMST-QMRA studies was conducted to summarize the state of the science and to identify research needs. The reviewed studies primarily aimed to identify what levels of MST marker genes in hypothetical recreational waterbodies would exceed the United States Environmental Protection Agency (USEPA) risk benchmarks for primary contact recreators. The QMRA models calculated relationships between MST marker gene(s) and reference pathogens based on published data in the literature. The development of a robust, accurate relationship was identified as an urgent research gap for qMST-QMRA. This metric requires additional knowledge to quantify the relationship between MST marker genes and the degree of variability in decay of pathogens as a dynamic function of environmental conditions and combinations of fecal sources at multiple spatial and temporal scales. Improved characterization of host shedding rates of host-associated microorganisms (i.e., MST marker genes), as well as fate and transport of these microorganisms and their nucleic acids, would facilitate expansion of this approach to other exposure pathways. Incorporation of information regarding the recovery efficiency, and host-specificity of MST marker genes into QMRA model parameters, and the sensitivity analysis, would greatly improve risk management and site-specific water monitoring criteria.
近年来，由于需要将点源和非点源粪便污染归因于特定来源，微生物源追踪（MST）标记基因的使用有所增加。定量微生物风险评估（QMRA）是一种建模方法，用于估计接触粪便污染水和相关病原体的健康风险。与依赖传统粪便指示细菌（FIB）相比，这些方法的结合（定量 MST（qMST）和 QMRA）可以为优先处理和解决健康风险提供额外的与病原体相关的信息。为了提供这种方法的扩展信息，对已发表的 qMST-QMRA 研究进行了综述，以总结该领域的科学现状并确定研究需求。审查的研究主要旨在确定在假设的娱乐性水体中，MST 标记基因的水平将超过美国环境保护署（USEPA）针对主要接触娱乐者的风险基准。QMRA 模型根据文献中的已发表数据计算 MST 标记基因与参考病原体之间的关系。建立稳健、准确的关系被确定为 qMST-QMRA 的紧迫研究空白。该指标需要更多的知识来量化 MST 标记基因与病原体衰减的变异性之间的关系，作为环境条件和多个时空尺度上多种粪便源的动态函数。宿主相关微生物（即 MST 标记基因）的宿主脱落率的更好描述，以及这些微生物及其核酸的命运和迁移，将有助于将这种方法扩展到其他暴露途径。将 MST 标记基因的回收率和宿主特异性信息纳入 QMRA 模型参数，并进行敏感性分析，将极大地改善风险管理和特定地点的水监测标准。
