Evaluation of rapid qPCR method for quantification of E. coli at non-point source impacted Lake Michigan beaches

Evaluation of rapid qPCR method for quantification of E. coli at non-point source impacted Lake... Most Great Lakes communities rely on culture-based E. coli methods for monitoring fecal indicator bacteria (FIB) at recreational beaches. These cultivation methods require 18 or more hours to generate results. As a consequence, public notifications about beach action value (BAV) exceedance are based on prior-day water quality. Rapid qPCR monitoring of bacteria in beach water solves the 24-h delay problem, though the USEPA-approved qPCR method targets enterococci bacteria, while Great Lakes communities are familiar with E. coli monitoring. For an E. coli qPCR method to be useful for water quality management, it is important to systematically characterize method performance, and establish BAVs for public notification purposes. In this study, we 1) evaluated a draft USEPA E. coli qPCR method, 2) compared E. coli qPCR measurements with two established FIB (E. coli culture and enterococci qPCR) results, and explored potential strategies to establish E. coli qPCR BAV criteria in the absence of an epidemiological study. Based on analyses of 288 water samples collected from eight of Chicago's Lake Michigan beaches, the E. coli qPCR method demonstrates acceptable performance characteristics. The method is prone to low level DNA contamination, possibly originating from assay reagents derived from E. coli bacteria. Both E. coli and enterococci BAVs were exceeded in approximately 18% of the samples. E. coli qPCR values were correlated with both E. coli culture (r = 0.83; p < 0.0001) and enterococci qPCR (r = 0.67; p < 0.0001) values. The approach recommended by the USEPA in its Technical Support Material (TSM) was used to generate candidate E. coli qPCR BAVs, as was receiver operating characteristic (ROC) analysis. Potential BAV thresholds differed substantially, ranging from 200.9 calibrator cell equivalents (CCE)/100 mL (ROC analysis, enterococci qPCR BAV as the reference) to 1000 CCE/100 mL (TSM analysis, enterococci qPCR BAV as the reference). Because we found that different approaches to establishing potential BAVs generate quite different values, guidance from USEPA about approaches to defining comparable BAVs would be useful. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Water Research Elsevier

Evaluation of rapid qPCR method for quantification of E. coli at non-point source impacted Lake Michigan beaches

Loading next page...
 
/lp/elsevier/evaluation-of-rapid-qpcr-method-for-quantification-of-e-coli-at-non-ZneUdkB31f
Publisher
Elsevier
Copyright
Copyright © 2019 The Authors
ISSN
0043-1354
D.O.I.
10.1016/j.watres.2019.03.034
Publisher site
See Article on Publisher Site

Abstract

Most Great Lakes communities rely on culture-based E. coli methods for monitoring fecal indicator bacteria (FIB) at recreational beaches. These cultivation methods require 18 or more hours to generate results. As a consequence, public notifications about beach action value (BAV) exceedance are based on prior-day water quality. Rapid qPCR monitoring of bacteria in beach water solves the 24-h delay problem, though the USEPA-approved qPCR method targets enterococci bacteria, while Great Lakes communities are familiar with E. coli monitoring. For an E. coli qPCR method to be useful for water quality management, it is important to systematically characterize method performance, and establish BAVs for public notification purposes. In this study, we 1) evaluated a draft USEPA E. coli qPCR method, 2) compared E. coli qPCR measurements with two established FIB (E. coli culture and enterococci qPCR) results, and explored potential strategies to establish E. coli qPCR BAV criteria in the absence of an epidemiological study. Based on analyses of 288 water samples collected from eight of Chicago's Lake Michigan beaches, the E. coli qPCR method demonstrates acceptable performance characteristics. The method is prone to low level DNA contamination, possibly originating from assay reagents derived from E. coli bacteria. Both E. coli and enterococci BAVs were exceeded in approximately 18% of the samples. E. coli qPCR values were correlated with both E. coli culture (r = 0.83; p < 0.0001) and enterococci qPCR (r = 0.67; p < 0.0001) values. The approach recommended by the USEPA in its Technical Support Material (TSM) was used to generate candidate E. coli qPCR BAVs, as was receiver operating characteristic (ROC) analysis. Potential BAV thresholds differed substantially, ranging from 200.9 calibrator cell equivalents (CCE)/100 mL (ROC analysis, enterococci qPCR BAV as the reference) to 1000 CCE/100 mL (TSM analysis, enterococci qPCR BAV as the reference). Because we found that different approaches to establishing potential BAVs generate quite different values, guidance from USEPA about approaches to defining comparable BAVs would be useful.

Journal

Water ResearchElsevier

Published: Jun 1, 2019

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create folders to
organize your research

Export folders, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off