[Detection of enteric pathogenic bacteria from surface waters by quantitative polymerase chain reaction (QPCR)]

Huan Jing Ke Xue. 2008 May;29(5):1175-80.
[Article in Chinese]

Abstract

A rapid quantitative polymerase chain reaction (QPCR) analysis method with universal primers was developed to detect cell densities of the enteric pathogenic bacteria from 5 surface water of Xi'an City for 4 months continuously. And the detection results by QPCR method were compared with counts of coliforms colony-forming units (CFU) determined by membrane filter (MF) analysis. The results showed that QPCR method had an estimated 94% confidence, and detection limit was 2.7 Escherichia coli cells per sample in undiluted DNA extracts. For five surface waters (N = 60), the geometric mean of pathogenic bacteria concentration determined by QPCR was 2.2-5 times of corresponding coliform CFU determined by MF analysis. Using QPCR analysis, these geometric means of pathogenic bacteria concentration ranged from 25 CCE/100 mL to 67 000 CCE/100 mL. Using MF culture analysis, coliforms ranged from 3 CFU/100 mL to 45 000 CFU/100 mL. Regression analysis showed that there was a significant positive correlation between pathogenic bacteria determined by QPCR method and coliforms determined by MF method, the correlation coefficient (r) was 0.983.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Enterobacteriaceae / genetics
  • Enterobacteriaceae / isolation & purification*
  • Escherichia coli / genetics
  • Escherichia coli / isolation & purification
  • Polymerase Chain Reaction / methods*
  • RNA, Ribosomal, 16S / genetics
  • Salmonella typhi / genetics
  • Salmonella typhi / isolation & purification
  • Sequence Analysis, DNA
  • Shigella dysenteriae / genetics
  • Shigella dysenteriae / isolation & purification
  • Water Microbiology*
  • Water Pollution / analysis*

Substances

  • RNA, Ribosomal, 16S