title: Application of Reverse Transcriptase -PCR (RT-PCR) for rapid detection of viable Escherichia coli in drinking water samples.
abstract: BACKGROUND
  Polymerase chain reaction (PCR) is preferred to other methods for detecting Escherichia coli (E. coli) in water in terms of speed, accuracy and efficiency. False positive result is considered as the major disadvantages of PCR. For this reason, reverse transcriptase-polymerase chain reaction (RT-PCR) can be used to solve this problem. The aim of present study was to determine the efficiency of RT-PCR for rapid detection of viable Escherichia coli in drinking water samples and enhance its sensitivity through application of different filter membranes.
  
  
  METHODS
  Specific primers were designed for 16S rRNA and elongation Factor II genes. Different concentrations of bacteria were passed through FHLP and HAWP filters. Then, RT-PCR was performed using 16srRNA and EF -Tu primers. Contamination of 10 wells was determined by RT-PCR in Arak city. To evaluate RT-PCR efficiency, the results were compared with most probable number (MPN) method.
  
  
  RESULTS
  RT-PCR is able to detect bacteria in different concentrations. Application of EF II primers reduced false positive results compared to 16S rRNA primers. The FHLP hydrophobic filters have higher ability to absorb bacteria compared with HAWB hydrophilic filters. So the use of hydrophobic filters will increase the sensitivity of RT-PCR.
  
  
  CONCLUSIONS
  RT-PCR shows a higher sensitivity compared to conventional water contamination detection method. Unlike PCR, RT-PCR does not lead to false positive results. The use of EF-Tu primers can reduce the incidence of false positive results. Furthermore, hydrophobic filters have a higher ability to absorb bacteria compared to hydrophilic filters.
authors: Department of Microbiology and Immunology, Arak University of Medical sciences, Arak, Iran.
authors: Neda
authors: N
authors: Molaee
authors: Molecular and Medicine Research Center, Arak University of Medical Sciences, Arak, Iran.
authors: Hamid
authors: H
authors: Abtahi
authors: Department of Environmental Health, Faculty of Health, Arak University of Medical Sciences, Arak, Iran.
authors: Mohammad Javad
authors: MJ
authors: Ghannadzadeh
authors: Department of Medical Microbiology and Immunology, Arak University of Medical sciences, Arak, Iran.
authors: Masoude
authors: M
authors: Karimi
authors: Molecular and Medicine Research Center, Arak University of Medical Sciences, Arak, Iran ; Department of Medical Microbiology and Immunology, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran.
authors: Ehsanollah
authors: E
authors: Ghaznavi-Rad
keywords: Coliforms; Drinking water; Reverse transcriptase