Characterisation of pathogenic bacteria in a UASB-polishing pond system using molecular techniques

Area of Science:

• Environmental Microbiology
• Molecular Biology
• Wastewater Treatment

Background:

• Molecular techniques are widely used for pathogen detection in various samples.
• Limited studies have applied these methods to wastewater treatment plants (WWT).
• Wastewater treatment requires effective monitoring for pathogenic bacteria removal.

Purpose of the Study:

• To investigate pathogenic bacteria in a wastewater treatment plant using PCR and FISH.
• To assess the removal efficiency of specific pathogens within the system.
• To evaluate the applicability of molecular methods for wastewater monitoring.

Main Methods:

• Polymerase Chain Reaction (PCR) with specific primers for pathogen detection.
• Fluorescence In Situ Hybridization (FISH) for quantifying Escherichia coli abundance.
• Analysis of samples from raw sewage, UASB reactor, and pond effluents.

Main Results:

• Escherichia coli and Salmonella enterica subsp. enterica were detected in raw sewage and effluents.
• Shigella dysenteriae and Enterococcus spp. were found in raw sewage and UASB effluent but not pond effluent.
• FISH quantified E. coli at 10(7) cells/100 mL in raw sewage and 10(6) cells/100 mL in pond effluent.

Conclusions:

• PCR is applicable for monitoring pathogenic bacteria in wastewater systems.
• The studied wastewater treatment plant did not completely remove all targeted pathogens.
• Further studies with more samples are needed to validate FISH for WWT effluent monitoring.