Version 1
: Received: 21 October 2024 / Approved: 21 October 2024 / Online: 21 October 2024 (17:23:25 CEST)
How to cite:
McNair, J. N.; Rediske, R. R.; Hart, J. J.; Briggs, S. Performance of Colilert-18 and qPCR for Monitoring E. coli Contamination at Freshwater Beaches in Michigan. Preprints2024, 2024101649. https://doi.org/10.20944/preprints202410.1649.v1
McNair, J. N.; Rediske, R. R.; Hart, J. J.; Briggs, S. Performance of Colilert-18 and qPCR for Monitoring E. coli Contamination at Freshwater Beaches in Michigan. Preprints 2024, 2024101649. https://doi.org/10.20944/preprints202410.1649.v1
McNair, J. N.; Rediske, R. R.; Hart, J. J.; Briggs, S. Performance of Colilert-18 and qPCR for Monitoring E. coli Contamination at Freshwater Beaches in Michigan. Preprints2024, 2024101649. https://doi.org/10.20944/preprints202410.1649.v1
APA Style
McNair, J. N., Rediske, R. R., Hart, J. J., & Briggs, S. (2024). Performance of Colilert-18 and qPCR for Monitoring E. coli Contamination at Freshwater Beaches in Michigan. Preprints. https://doi.org/10.20944/preprints202410.1649.v1
Chicago/Turabian Style
McNair, J. N., John J. Hart and Shannon Briggs. 2024 "Performance of Colilert-18 and qPCR for Monitoring E. coli Contamination at Freshwater Beaches in Michigan" Preprints. https://doi.org/10.20944/preprints202410.1649.v1
Abstract
Fecal contamination is a common cause of impairment of surface waters. In monitoring studies, it usually is assessed by measuring concentrations of fecal indicator bacteria such as Escherichia coli (E. coli), a common monitoring target in freshwater systems. In this study, we assess the advantages and disadvantages of two common methods for monitoring E. coli concentrations at freshwater beaches: Colilert-18®, with a turnaround time of ca. 18 h, and real-time quantitative PCR (qPCR), with a turnaround time of ca. 3–4 h. Based on data comprising 3081 pairs of Colilert-18 and qPCR estimates of E. coli concentrations in split samples from Michigan’s annual beach monitoring program in 2019 and 2020, we found that qPCR monitoring detected a high percentage of exceedances of the state’s water quality standard for E. coli contamination that went undetected on the day of sampling with Colilert-18 monitoring, because qPCR concentration estimates were available on the day of sampling but Colilert-18 estimates were not. However, Colilert-18 data were more useful than qPCR data for statistical comparison of contamination levels at different beaches, probably in part because Colilert-18 data showed a much lower percentage of censored concentration estimates (estimates outside the range of quantification).
Keywords
Beach monitoring; Recreational water quality; Fecal indicator bacteria (FIB); Escherichia coli (E. coli); Real-time quantitative polymerase chain reaction (qPCR); Colilert-18; EPA draft method C; censored data
Subject
Environmental and Earth Sciences, Water Science and Technology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
