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Detection of Live Escherichia coli O157:H7 Cells by PMA-qPCR
Published on: February 1, 2014
A filter-based propidium monoazide technique to distinguish live from membrane-compromised microorganisms using
Kristen N Hellein1, Elizabeth M Kennedy, Valerie J Harwood
1Center for Environmental Diagnostics and Bioremediation, University of West Florida, 11000 University Parkway, Pensacola, FL 32514, USA.
Journal of Microbiological Methods
|February 9, 2012
Summary
Propidium monoazide (PMA) effectively distinguishes live from dead bacteria in water samples using qPCR. This validated method ensures accurate microbial detection in environmental samples.
Area of Science:
- Microbiology
- Molecular Biology
- Environmental Science
Background:
- Accurate differentiation of viable bacteria is crucial for water quality assessment.
- Traditional methods may not reliably distinguish between live and membrane-compromised cells.
- Propidium monoazide (PMA) is a DNA-intercalating dye used to exclude DNA from dead cells in PCR.
Purpose of the Study:
- To adapt and validate the use of PMA for differentiating live from membrane-compromised bacteria in membrane-filtered water samples.
- To assess the efficacy of PMA in conjunction with quantitative PCR (qPCR).
Main Methods:
- Adaptation of PMA staining technique for membrane-filtered water samples.
- Application of quantitative PCR (qPCR) to analyze bacterial viability.
- Independent laboratory replication to ensure reproducibility.
Main Results:
- PMA successfully differentiated live from membrane-compromised bacteria in water samples.
- The adapted technique demonstrated high efficacy when combined with qPCR.
- Results were consistently replicated across three independent institutions.
Conclusions:
- The PMA-qPCR method is a reliable and reproducible technique for assessing bacterial viability in water samples.
- This method enhances the accuracy of microbial monitoring in environmental water sources.
- The findings support the widespread adoption of this technique in water quality testing.
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