Category Archives: Current Lab Members

Alyssa Grube

Alyssa is a first year MS/PhD student in the department of Environmental Science & Engineering. She graduated from Juniata College in Pennsylvania in May 2014 with a degree in Biology and Spanish. Prior to beginning graduate school, she spent a year in Chile as part of a Fulbright research fellowship. Alyssa’s research will focus on the application of metagenomic tools to track the distribution and abundance of class I integrons and associated resistance genes in the Galapagos Islands. Outside of lab, Alyssa enjoys hiking, making empanadas, and quilting.

Sharon Jiang

Sharon is a first year Master’s student in the Department of Environmental Sciences and Engineering at the University of North Carolina at Chapel Hill. She obtained her Bachelor of Science in Public Health at UNC in May 2016 and is part of the Dual Bachelor’s-to-Master of Science Program. She is a current recipient of the UNC Graduate School Masters Merit Assistantship for study in Environmental Sciences and Engineering. Sharon is studying the potential contribution of lysogenic phages in coliphage enumeration methods. She has also participated in environmental microbiological studies involving disk diffusion antibiotic sensitivity testing and beach water quality monitoring.

Claire Tipton

Claire Tipton_ UNC Head ShotClaire is a second year Masters student in the Environmental Sciences & Engineering Department. She is interested in pursuing a career in environmental consulting and water resource management upon completion of her degree (May 2017). For her Master’s Thesis project, Claire is working with the water quality test company Aquagenx. LLC to field and lab verify a new line of drinking water safety products. Before graduate school, Claire attained stormwater regulatory experience as a Water Quality Technician with The City of Durham Stormwater & GIS Services Division. She obtained her Bachelor of Science degree from Elon University in Environmental & Ecological Sciences, with minors in Biology and Spanish. In her free time, Claire enjoys playing rugby, running, and honing her archery skills at the local range.

Elizabeth Christenson

Elizabeth finished her master’s at UNC with Dr. Marc Serre improving access to industrial hog farm data by mapping sprayfields and their annual nutrient application patterns in North Carolina using GIS and remote sensing. Data available here.  Her current work as a PhD student is implementing a longitudinal water quality study to understand how land use characteristics affect the prevalence of antibiotic resistant, virulent E. coli and host-specific markers in watersheds with and without swine CAFOs.  Laboratory work includes culture-based work and ddPCR.  Spatial analysis will include wetland and riparian buffer variables. Areas of interest include microbial source tracking, potentially metagenomics in the future, worker/community member access to safe drinking water, and sustainable agriculture. After work, Elizabeth is learning Arabic (صحيح ), grows sunflowers, and plays ultimate frisbee.

Elizabeth’s CV

Jianyong Wu

Wu_Jianyong_headshot2Jianyong is a postdoctoral fellow. He received his Ph.D. from the University of North Carolina at Chapel Hill. With a background in both environmental health microbiology and medical geography, he has broad interests in water-related public health issues, including detection of microbial indicators and pathogens, risk factors for waterborne diseases, health effects of land cover and climate change. He has been trained in both experiment-based skills, such as molecular biology, and computing-based skills, such as remote sensing, GIS, Bayesian statistics and mathematical modeling. In addition, he is proficient in data collection, management and analysis. To date, he has over 20 peer-reviewed journal publications.

Billy Gerhard

Billy-Turtle-copyBilly graduated in August 2015 with his MSPH. His master’s research focused on the use of molecular methods to identify the source of drinking water contamination in the Galapagos Islands. He still works with the lab as a visiting scholar and with the Center for Galapagos Studies as a graduate affiliate. Billy is currently a Ph.D. student in Environmental Process Engineering at Duke University where his research investigates the role of ballast water as a mode of pathogen transport and offers insight to effective remediation strategies..

David Holcomb

David is researching strategies to assess exposure to microbes in the environment. He is using molecular techniques to characterize fecal contamination in the household environment in urban Maputo, Mozambique. This research will be used to evaluate a large-scale sanitation intervention and its effects on child health. He is also working on a geostatistical tool to predict microbial contamination at the watershed level, and is developing a statistical framework for estimating the contribution of different fecal pollution sources in a set of environmental samples.

Visit David’s website for a current CV and publications.

Sarah Rhodes

Sarah is a Ph.D. candidate and laboratory manager for the Stewart Lab. Her interests include infectious disease microbiology, waste management justice, environmental justice, sustainable agriculture, and community climate resilience. Sarah is conducting her research in partnership with the Rural Empowerment Association for Community Help (REACH), a community-based organization located in Duplin County, North Carolina (NC), the epicenter of hog and poultry production in the world. Sarah’s work with REACH aims to characterize the disparate impact of industrial animal production processes on the health of underrepresented rural communities and the environment in NC. More specifically, her doctoral research evaluates the impact of antibiotic use in food animal production on the evolution and dissemination of antibiotic resistant bacteria among vulnerable populations, such as industrial hog operation workers and community members living near hog operations, in addition to key environmental reservoirs. Sarah hopes to complete her doctoral degree in May 2018.

Sarah Hatcher

Sarah is a postdoctoral trainee investigating the association between occupational and environmental exposure to industrial livestock operations and antibiotic-resistant Staphylococcus aureus nasal carriage and infection. She is also working on pilot research to validate microbial source tracking (MST) markers in air samples. Sarah was a NSF GRFP Fellow and received her Ph.D. from the Department of Environmental Sciences and Engineering at UNC-Chapel Hill. Under the direction of Dr. Stewart, her doctoral research investigated exposure to antibiotic-resistant Staphylococcus aureus among industrial hog operation workers and their <7 year old household members, compared to a group of community referent participants. As a graduate student, she also mentored undergraduate students investigating beach water quality in the Galapagos Islands, Ecuador. Her interests include microbial source tracking, emerging infectious disease viewed through a One Health lens, and applied epidemiology. Sarah is also interested in science communication and the use of citizen science and community-driven research to investigate environmental health disparities and empower communities.

Sarahs CV