Institute: West Virginia
Year Established: 2020 Start Date: 2020-03-01 End Date: 2021-02-28
Total Federal Funds: $19,923 Total Non-Federal Funds: $39,921
Principal Investigators: Emily Garner
Abstract: Acid mine drainage (AMD) can impair water quality in surface water through elevated metals, high total dissolved solids, and low pH. Waterways impacted by AMD are often located in rural areas that lack service by municipal wastewater systems and receive inputs from a variety of fecal pollution sources, such as failing septic tanks and straight piping, direct access by livestock or runoff from manure treated fields, and wildlife. Fecal coliforms and Escherichia coli are often used as fecal indicator bacteria to approximate pathogen loading associated with fecal contamination to waterways, while eliminating the need to laboriously monitor multiple pathogens of interest. Monitoring of fecal coliforms is well-established as a low-cost and accessible method to monitor fecal contamination, and easy-to-use commercial enzymatic approaches (e.g. IDEXX Colilert-18) have made this approach widely utilized. Fecal coliforms are also widely monitored to measure progress of watershed restoration projects, and to enforce total maximum daily loading limits. Previous research has demonstrated that environmental stress associated with AMD waters can lead to sub-lethal injury in fecal coliforms, resulting in false negative monitoring results or sub-accurate enumeration using culture-based methods. Other characteristics of water quality associated with AMD (i.e. low pH, heavy metals, oxidative stress) have also been shown to induce a viable but non-culturable (VBNC) state in E. coli and other bacteria in other environments. Bacteria in a VBNC state are not detectable using traditional culture-based methods, but the efficacy of enzymatic methods is not well-established in the high environmental stress conditions typical of AMD. Yet, pathogenic coliforms, such as some strains of E. coli, are known to maintain virulence and the ability to infect human hosts, even in a VBNC state. Developing improved methods for accurate determination of fecal pollution source in waters likely to induce a VBNC state among monitoring targets is critical to allow watershed managers to accurately identify and remediate sources of contamination. The proposed research will include both a field survey of the Deckerâ€™s Creek watershed as well as controlled, laboratory-scale experimentation to address the following objectives:Objective 1: Determine the efficacy of standard culture and enzymatic methods to quantify total viable fecal coliforms and E. coli, including viable but non-culturable cells, in AMD-impacted waters. Objective 2: Develop and validate modifications to easy-to-use enzymatic methods for fecal coliform and E. coli enumeration that minimize false negative or sub-accurate quantification in AMD-impacted waters. Objective 3: Assess the suitability of fecal coliforms as an approximation of viable human pathogens in AMD-impacted waters. Objective 4: Evaluate antibiotic resistance phenotypes of E. coli isolated from AMD-impacted vs. non-impacted watersheds. Successful completion of the proposed research will result in improved understanding of the accuracy of culture and enzymatic methods for monitoring fecal coliforms in AMD-impacted watersheds and develop approaches to improve their accuracy. Additionally, the proposed work will highlight potential human health impacts associated with fecal pollution in AMD-impacted waters by investigating the suitability of monitoring fecal coliforms and E. coli as indicator bacteria as an approximation for human pathogens in AMD-impacted waters, and assessing impacts of AMD on E. coli antibiotic resistance phenotypes.