Quantification of viable bacteria in wastewater treatment plants by using propidium monoazide combined with quantitative PCR (PMA-qPCR)

J Environ Sci (China). 2014 Feb 1;26(2):299-306. doi: 10.1016/s1001-0742(13)60425-8.

Abstract

The detection of viable bacteria in wastewater treatment plants (WWTPs) is very important for public health, as WWTPs are a medium with a high potential for waterborne disease transmission. The aim of this study was to use propidium monoazide (PMA) combined with the quantitative polymerase chain reaction (PMA-qPCR) to selectively detect and quantify viable bacteria cells in full-scale WWTPs in China. PMA was added to the concentrated WWTP samples at a final concentration of 100 micromol/L and the samples were incubated in the dark for 5 min, and then lighted for 4 min prior to DNA extraction and qPCR with specific primers for Escherichia coli and Enterococci, respectively. The results showed that PMA treatment removed more than 99% of DNA from non-viable cells in all the WWTP samples, while matrices in sludge samples markedly reduced the effectiveness of PMA treatment. Compared to qPCR, PMA-qPCR results were similar and highly linearly correlated to those obtained by culture assay, indicating that DNA from non-viable cells present in WWTP samples can be eliminated by PMA treatment, and that PMA-qPCR is a reliable method for detection of viable bacteria in environmental samples. This study demonstrated that PMA-qPCR is a rapid and selective detection method for viable bacteria in WWTP samples, and that WWTPs have an obvious function in removing both viable and non-viable bacteria. The results proved that PMA-qPCR is a promising detection method that has a high potential for application as a complementary method to the standard culture-based method in the future.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Azides*
  • Enterococcus
  • Escherichia coli
  • Polymerase Chain Reaction
  • Propidium / analogs & derivatives*
  • Sewage / microbiology*
  • Wastewater / microbiology*
  • Water Microbiology*

Substances

  • Azides
  • Sewage
  • Waste Water
  • propidium monoazide
  • Propidium