Evaluation of Techniques for Measuring Microbial Hazards in Bathing Waters: A Comparative Study.

Area of Science:

• Environmental microbiology
• Water quality assessment
• Analytical chemistry

Background:

• Culture-based faecal indicator organism (FIOs) assays are standard for recreational water quality monitoring.
• These traditional methods are time-consuming, costly, non-specific, and prone to user bias.

Purpose of the Study:

• To compare the performance of industry-standard IDEXX methods with three alternative water quality monitoring approaches.
• To evaluate the TECTA™ system, US EPA Method 1611 (qPCR), and Next Generation Sequencing (NGS) against established assays.

Main Methods:

• 233 water samples from diverse environments were analyzed using IDEXX (Colilert, Enterolert), TECTA™ system, US EPA Method 1611, and NGS.
• Comparative analysis focused on accuracy, speed, cost, and user-dependency.

Main Results:

• TECTA™ system demonstrated strong correlation with IDEXX for E. coli and enterococci, offering faster results (~12 hrs vs 24 hrs) and reduced user bias.
• US EPA Method 1611 (qPCR) correlated with IDEXX for enterococci but incurred higher costs and technical demands.
• NGS showed significant correlations with FIOs, Enterobacteriaceae, and Enterococcaceae, despite high initial costs and analysis time.

Conclusions:

• The TECTA™ system presents a viable, efficient alternative to traditional methods for recreational water quality monitoring.
• While qPCR and NGS show promise, their current implementation faces economic and technical barriers.
• Technological advancements in NGS suggest its future widespread adoption in water quality analysis.