Elizabeth Wolyniak has been leading the charge to uncover critical dynamics of Cryptosporidium accumulation and transport in biofilms.
by Karen Kegel
Cryptosporidium is an ongoing source of concern within the drinking water industry. A contaminant of more than 15% of drinking water in the United States, the human pathogen is associated with symptoms such as diarrhea, nausea, and low-grade fevers. Alarmingly, infections can be fatal among those who are immunocompromised, including HIV and cancer patients. It stands to reason that improving environmental control of this protozoan parasite is now a key focus of the field.
Elizabeth Wolyniak at Pocono Creek
Recently, Lehigh University graduate student Elizabeth Wolyniak has been leading the charge to uncover critical dynamics of Cryptosporidium accumulation and transport in biofilms, or microbial communities that thrive on surfaces exposed to water. Her groundbreaking research investigated seasonal changes in oocyst attachment to biofilms and has resulted in several important findings.
First presented at the American Society for Microbiology’s annual General Meeting and soon to be reported in Applied and Environmental Microbiology (full article available), a consistent pattern of oocyst attachment and detachment was found over 8-day intervals. Some of the oocysts that attached to biofilms during the first 3 days detached from them in the days that followed, once oocyst-free water was introduced into the system. The process left a new steady state portion of oocysts, suggesting Cryptosporidium reservoirs may persist in biofilms and contaminate water previously deemed safe. Elizabeth also detected seasonal differences in oocyst attachment, with spring biofilms containing the greatest counts and fall the least.
Beyond highly promising results, the methodology developed for this project has the potential to transform future research with biofilms. Typically, researchers are reluctant to analyze biofilms outside their natural environment because of changes brought on by collection and transit and the complicated nature of environmental biofilms. Elizabeth developed a method to recreate environmental biofilms in the lab by scraping biofilms from rocks at her 3 sample locations—Monocacy Creek, Pocono Creek, and Cranberry Creek—and then concentrating the material in the lab at Lehigh. Biofilms were subsequently grown in flow chambers and examined using the Biological Science department’s scanning confocal laser microscope.
The knowledge and resources of two Lehigh departments helped bring this fifth year graduate student’s research interests into successful fruition. Advised by Dr. Bruce Hargreaves in Earth and Environmental Science and Dr. Kristen Jellison in Civil and Environmental Engineering, Elizabeth notes she has “really enjoyed working between departments and gaining new perspectives on [her] work.” The project was funded in part by a National Science Foundation CAREER grant awarded to Dr. Jellison in 2006.
Winter biofilm collection
Of course, the research doesn’t stop with publication. Several other laboratories are tracking Elizabeth et al.’s planned next steps, including work on the role of water quality parameters and biofilm composition in oocyst attachment. Passionate about environmental education and water quality protection, Elizabeth is also looking forward to applying her knowledge of biofilms to watershed monitoring. Hopefully, public water supplies will see less Cryptosporidium contamination and fewer outbreaks of infection as the science continues to unfold.