A new, automated rapid fluorometric method for the detection of Escherichia coli in recreational waters

Abstract

Membrane filtration/culture techniques have been demonstrated to be reliable and broadly applicable for determination of fecal contamination in recreational waters. The time-consuming nature of culture techniques, however, is viewed as the major disadvantage of this type of analysis, and many authors have asserted the need for improved rapid-detection methods. In this study, we evaluated the performance of the ENDETEC™ TECTA™ B16, an automated fluorometry-based microbial detection system, by comparing its detection time and accuracy to those of two common culture-based methods, which are widely-used for recreational water quality monitoring in Canada. Our results demonstrated that Escherichia coli densities inferred by the TECTA™ method were generally in agreement with those generated by standard culture methods (y=1.19x+0.002, R2=0.89) and under the current calibration regime, TECTA™ tended to slightly overestimate E. coli densities. In addition, TECTA™ was able to detect E. coli densities in exceedance of the Ontario Provincial Water Quality Objective for recreational waters in as little as 4h (mean detection time=7.03h), representing a substantial improvement over traditional culture techniques. Our findings suggest that with improved calibration, TECTA™ may provide a viable, cost-effective, rapid alternative to culture approaches for the detection of fecal contamination in recreational waters.