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This paper discusses two methods for the rapid assessment of microorganisms in public recreational waters. Twodifferent approaches have been selected: the first method was a fluorimetric measure ofthe -D- glucuronidase activity based on the hydrolysis of the substrate 4 methylumbelliferyl--D-glucuronide; and, the second approach was a molecular test based on real-time ReverseTranscription - Polymerase Chain Reaction (quantitative RT-PCR) for specific quantificationof E. coli 16S rRNA molecules. Special effort was made to standardize and automate thequantitative RT-PCR analysis, especially for the RNA extraction and purification steps.The objective of this study was to evaluate the capacity of both methods used forthe rapid assessment of bathing water samples. A total of 549 samples and 252 samplescollected from two different coastal sites (French Atlantic coast) and freshwater wererespectively analyzed by the fluorimetric and RT-PCR assays. Results show that both methodsare rapid: 1 hour for 6 samples analyzed by one fluorescence spectrophotometer; or, 3 hoursfor the simultaneous analysis of up to 15 samples by using a KingFisher mL (Thermo Fisher)robotic processor and real-time PCR apparatus (R.A.P.I.D. LT, Idaho Technology Inc.). Withregard to the microbiological criteria of the current regulation, the results obtained with thefluorimetric and RT-PCR analysis compared with the standard method (ISO 9308-3) arecongruent in more than 81% of analyzed samples.Because these methods provide a faster assessment of water quality, they have thepotential to significantly reduce health risk resulting from exposure to recreational waters andalso reduce errors in beach closings. The potential ability of these alternative methods to bemore protective than the reference method is also discussed. Includes 17 references, tables, figures.

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Edition: Vol. - No. Published: 11/01/2007 Number of Pages: 8File Size: 1 file , 320 KB