My name is Kanghee Ryu, and I am a PhD candidate at the School of Public Health at the University of Alberta. I have the privilege of working under the guidance of Dr. Norman Neumann, an exceptional researcher and supervisor. Our research group is to studying microorganisms isolated from water resources, including wastewater and stormwater.
Water treatment is a cornerstone of public health and has significantly reduced diseases like cholera and typhoid fever since the early 20th century. The advent of modern water treatment technologies, including chlorination and UV irradiation, has had a profound impact on public health worldwide. Despite this advancement, new challenges arise. Extraintestinal Pathogenic Escherichia coli (ExPEC) has become a significant threat in water environments. ExPEC is known for causing severe infections outside the intestines, such as urinary tract infections, bloodstream infections, and neonatal meningitis. These bacteria demonstrate remarkable survival in various water sources, including surface water, drinking water, and wastewater. Recent findings highlight their multidrug-resistant nature and virulence genes, presenting a formidable challenge to public health globally. In Sweden, 74% of antibiotic-resistant E. coli detected in surface water samples were resistant to three or more antibiotics. In Lebanon, 21% of ESBL-producing E. coli isolates from water sources carried ExPEC virulence factors. ESBLs (Extended-Spectrum Beta-Lactamases) are enzymes that confer resistance to a wide range of beta-lactam antibiotics, making these infections difficult to treat.
Our research group recently discovered that chlorine-resistant ExPEC isolates from wastewater plants in Alberta were found to have identical virulence gene combinations as genetically related clinical ExPEC strains, with 96-98% genome similarity. Additionally, some of wastewater-borne ExPEC isolates were identified as multi-drug resistant strains. The persistence of ExPEC in treated wastewater poses several risks. Contaminated wastewater can lead to infections through recreational activities, drinking water supplies, and irrigation. Furthermore, ExPEC can persist in the environment for extended periods, increasing the risk of exposure. The presence of antibiotic-resistant ExPEC in water also contributes to the broader issue of antibiotic resistance. We are currently investigating how these pathogenic E. coli survive under harsh conditions, such as chlorine exposure, unfavorable temperatures (i.g., heat and cold), hypo-osmosis, and nutrient deficiency. Understanding these survival mechanisms is crucial for developing more effective water treatment methods and public health interventions. This knowledge helps in developing effective strategies to combat bacterial infections, prevent the spread of resistant strains, and ensure the safety and sustainability of water resources.
The emergence of ExPEC as a concern in water environments underscores the need for ongoing research, innovation, and vigilance in wastewater management. Addressing these challenges helps protect public health and ensures the safety of our water resources. The World Health Organization (WHO) states that contaminated water can transmit diseases such as diarrhea, cholera, dysentery, typhoid, and polio, causing millions of deaths each year. Clean water is essential for everyone, and understanding these hidden threats helps us all stay safer.
Thanks for reading, and stay curious!
References:
Shuai Zhi, Paul Stothard, Graham Banting, Candis Scott, Kristin Huntley, Kanghee Ryu, Simon Otto et al. “Characterization of water treatment-resistant and multidrug-resistant urinary pathogenic Escherichia coli in treated wastewater.” Water research 182 (2020): 115827.
Daniel Yu, Kanghee Ryu, Simon JG Otto, Paul Stothard, Graham Banting, Norma Ruecker, Norman F. Neumann, and Shuai Zhi. “Differential survival of potentially pathogenic, septicemia-and meningitis-causing E. coli across the wastewater treatment train.” npj Clean Water 5, no. 1 (2022): 33.
World Health Organization: WHO. “Water, Sanitation and Hygiene (WASH),” November 7, 2019. https://www.who.int/health-topics/water-sanitation-and-hygiene-wash.
Written by: Kanghee Ryu
Kanghee is pursuing his PhD in the School of Public Health at the University of Alberta, under the supervision of Dr. Norman Neumann. He earned his MSc and BSc in Biomaterials Engineering in Korea, where his master’s research focused on bacteriophage treatment to combat pathogens as an alternative to traditional antibiotics. His doctoral research investigates the survival mechanisms of ExPEC bacteria in the harsh environments often found in wastewater treatment processes. Beyond academia, Ryu is deeply committed to community engagement and leadership. He established the Korean Football Club (KFC) in Edmonton and served as the YGP National President of the Association of Korean Canadian Scientists and Engineers (AKCSE).
IWA YWP Canada 