Research
The WHAM laboratory's research seeks to improve water quality and decrease the risk of waterborne disease. We employ techniques from microbiology, engineering, and microbial ecology to characterize aquatic microbial communities and quantify waterborne pathogens. Our research is highly interdisciplinary, including water utilities, microbiologists, clinicians, and building managers. We specialize in both traditional microbiology methods, such as plate culture, and advanced molecular and imaging techniques, including DNA sequencing, quantitative and digital polymerase chain reaction (qPCR & dPCR), flow cytometry, and fluorescence microscopy.
Selected Past Research
Characterizing Opportunistic Pathogens in Drinking Water Distribution Systems Across the United States
As a part of UT Austin's CO-DOWN project, which is funded by the US EPA and led by Prof. Mary Jo Kirisits, Katherine is working with colleagues at UT, the University of Michigan, and George Washington University to quantify opportunistic pathogens, including Legionella pneumophila, Pseudomonas aeruginosa, and species of nontuberculous mycobacteria in 44 drinking water distribution systems across the US.
Interactions between Free-Living Amoebae and Bacterial Opportunistic Pathogens
As part of her National Science Foundation Postdoctoral Research Fellowship in Biology, Katherine is studying how free-living amoebae contribute to the persistence and proliferation of bacterial opportunistic pathogens in drinking water, including how novel endosymbionts influence the interactions between amoebae and bacterial opportunistic pathogens. For additional information see the project information on the NSF Awards website.
Antimicrobial Resistance in Pseudomonas aeruginosa with Exposure to Sublethal Concentrations of Silver Nanomaterials
This work, which is led by Prof. Mary Jo Kirisits at UT Austin and funded by the National Science Foundation, seeks to characterize how antimicrobial resistance in the bacterial opportunistic pathogen Pseudomonas aeruginosa is impacted by exposure to sublethal concentrations of silver nanomaterials, which are increasingly being used in consumer and medical products and, as a result, are being released into the environment.
A Source-to-Tap Characterization of Nontuberculous Mycobacteria in a Full-Scale Drinking Water System
In this study, Katherine led a team of colleagues from the University of Michigan and the City of Ann Arbor Water Treatment Plant in quantifying nontuberculous mycobacteria (NTM) from source to tap. The open-access article was published in the American Society for Microbiology's Journal of Applied and Environmental Microbiology in August 2024.
Legionella pneumophila occurrence in reduced-occupancy buildings in 11 cities during the COVID-19 pandemic
In this study, Katherine and her co-lead Dr. Hannah Healy led a team of colleagues from ten research institutions in three countries in a rapid response study to investigate whether building shutdowns as a result of the onset of the COVID-19 pandemic caused increased concentrations of Legionella pneumophila in stagnant building plumbing water. The results of this study were published in Environmental Science: Water Research & Technology in August 2023.
Evaluating Online Flow Cytometry for Monitoring of Drinking Water Ozone Disinfection Systems
In this study, Katherine led a team of colleagues from the University of Michigan, City of Ann Arbor Water Treatment Plant, and Great Lakes Water Authority in evaluating the use of online flow cytometry for continuous monitoring of a full-scale drinking water ozone system. This article was published in Water Research in June 2024.
Methods for Detecting and Differentiating Opportunistic Premise Plumbing Pathogens (OPPPs) to Determine Efficacy of Control and Treatment Technologies
Katherine was the lead Ph.D. student on this Water Research Foundation Project (#4721), which sought to evaluate and standardize methods for the quantification of opportunistic pathogens in drinking water, including culture-based methods and qPCR. Microorganisms selected for method development included nontuberculous mycobacteria, Legionella pneumophila, Pseudomonas aeruginosa, and Acanthamoeba spp. The report and a fact sheet summarizing findings is available on the Water Research Foundation Website.