Assessment of Antibiotic-Resistant Bacteria in Wastewater Effluent and Surface Waters in the Spokane Region
Faculty Mentor
Krisztian Magori
Presentation Type
Oral Presentation
Start Date
5-7-2025 9:20 AM
End Date
5-7-2025 9:40 AM
Location
PUB 317
Primary Discipline of Presentation
Biology
Abstract
Wastewater treatment plants (WWTPs) remove contaminants and pathogens using processes like sedimentation, filtration, and disinfection, significantly reducing microbial loads before discharging treated water into the environment. Previous research has found that some bacteria (including pathogenic and antibiotic-resistant) can survive treatments. The rising prevalence of antibiotic resistance poses a serious public health threat, as resistant bacteria entering aquatic ecosystems can harm water quality and affect wildlife. We aim to assess the presence of antibiotic-resistant bacteria in treated and natural water sources in the Spokane region. We hypothesize that measurable levels of bacteria, including resistant strains, may persist after wastewater treatment, varying by site and proximity to discharge points. Three vials of water samples will be collected from six sites each: three WWTP effluents (Cheney, Spokane, and North Spokane), the Upper Spokane Falls Dam, Latah Creek, and the Spokane River. Municipal tap water sources from Spokane and Cheney will also be tested. 200 mL samples will be collected in sterile vials, transported on ice, and stored at 4°C in the lab. We will plate 100 µL aliquots from each sample on Tryptic Soy Agar (TSA) with and without antibiotics. Plates will be incubated at 37°C for a maximum 48 hours to evaluate bacterial growth. We anticipate detecting bacterial presence across multiple sites, with the potential to identify emerging patterns of antibiotic resistance. These results will help determine if WWTPs contribute to the environmental spread of antibiotic-resistant bacteria and will provide insight into the effectiveness of current treatment methods in mitigating this risk.
Recommended Citation
Merritt, Sayla M.; Hendry, Hailey K.; and Sonoiki, Oluwapelumi Hannah, "Assessment of Antibiotic-Resistant Bacteria in Wastewater Effluent and Surface Waters in the Spokane Region" (2025). 2025 Symposium. 3.
https://dc.ewu.edu/srcw_2025/op_2025/o1_2025/3
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Assessment of Antibiotic-Resistant Bacteria in Wastewater Effluent and Surface Waters in the Spokane Region
PUB 317
Wastewater treatment plants (WWTPs) remove contaminants and pathogens using processes like sedimentation, filtration, and disinfection, significantly reducing microbial loads before discharging treated water into the environment. Previous research has found that some bacteria (including pathogenic and antibiotic-resistant) can survive treatments. The rising prevalence of antibiotic resistance poses a serious public health threat, as resistant bacteria entering aquatic ecosystems can harm water quality and affect wildlife. We aim to assess the presence of antibiotic-resistant bacteria in treated and natural water sources in the Spokane region. We hypothesize that measurable levels of bacteria, including resistant strains, may persist after wastewater treatment, varying by site and proximity to discharge points. Three vials of water samples will be collected from six sites each: three WWTP effluents (Cheney, Spokane, and North Spokane), the Upper Spokane Falls Dam, Latah Creek, and the Spokane River. Municipal tap water sources from Spokane and Cheney will also be tested. 200 mL samples will be collected in sterile vials, transported on ice, and stored at 4°C in the lab. We will plate 100 µL aliquots from each sample on Tryptic Soy Agar (TSA) with and without antibiotics. Plates will be incubated at 37°C for a maximum 48 hours to evaluate bacterial growth. We anticipate detecting bacterial presence across multiple sites, with the potential to identify emerging patterns of antibiotic resistance. These results will help determine if WWTPs contribute to the environmental spread of antibiotic-resistant bacteria and will provide insight into the effectiveness of current treatment methods in mitigating this risk.
