Viable and Dead Bacterial Cells in Water: Development of a Novel Way to Accurately Assess Water Quality and Human Health Risk

Overview

Topic status: We're looking for students to study this topic.

Microbial contamination of water represents the most significant risk to human health on a global scale. An important challenge in water monitoring is the rapid, specific and sensitive detection of microbial indicators and waterborne pathogens. Given that the provision of safe drinking water is a fundamental driver of public health, addressing
drinking water quality issues in rural and regional parts of Australia is increasingly important.

Advances in molecular techniques such as Real-Time PCR technology enable rapid, specific and sensitive detection and identification of potential pathogenic microorganisms in environmental waters which are difficult and/or laborious to culture using traditional microbiological methods. Viable strains can enter an environment and then shift to a dormant state where they are viable but not culturable (VBNC). This can lead to a failure to detect potentially harmful pathogens that are present. VBNC is a survival strategy due to environmental stresses, for example, lack of nutrients, allowing the organism to survive for potentially long periods of time in rainwater tanks. VBNC may account for the seasonal nature of cholera outbreaks as a consequence of the survival for long periods of Vibrio cholerae in river sediments.

The presence of one or more pathogenic microorganisms along with fecal indicators could represent a significant health risk to users. The stain ethidium monoazide is a dye that can differentiate between live and dead cells in complex samples. The viable/dead stain used in combination with Real-Time PCR will be applied to assess water quality.

Hypothesis

That ethidium monoazide used in combination with Real-Time PCR will differentiate between live and dead pathogens in water sources.

  • Aim 1: Apply Real-Time PCR, incoporating ethidium monoazide, to determine the concentration of faecal indicator organisms in water sources
  • Aim 2: Measure the concentration of human pathogenic bacteria in water sources using the combined Real-Time PCR + ethidium monoazide method
  • Aim 3: Determine the dynamic range of Real-Time PCR + ethidium monoazide to reliably measure faecal and pathogenic bacteria in water sources

Methods and techniques that will be developed in the course of this project:

  • Extraction of bacterial DNA directly from water sources
  • Real-Time PCR
  • Fluorescence microscopy
Study level
Honours
Supervisors
QUT
Organisational unit

Science and Engineering Faculty

Research area

Cell and Molecular Biosciences

Contact
Please contact the supervisor.