Early warning of faecal contamination of water: a dual mode, automated system for high- (&amp;lt;1 hour) and low-levels (6-11 hours)

Tryland, Ingun; Samset, I. D.; Hermansen, Leonila F.; Berg, J. D.; Rydberg, Henrik

doi:10.2166/wst.2001.0742

Cited by 10 publications

(8 citation statements)

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“…They are simple to perform and do not require expensive instrumentation. Such assays are in demand for risk assessment of water supply systems for early warning of high FC concentrations, for example by monitoring of raw water quality (Tryland et al 2001), assessment of treatment efficiency, monitoring of finished water quality as well as recreational waters. They also have been recently exploited for daily monitoring of beach water quality .…”

Section: Application Of Rapid Enzymatic Assays For Bacterial Detectionmentioning

confidence: 99%

A biosensor platform for rapid detection of E. coli in drinking water

Hesari

Alum

El-Zein

et al. 2016

Enzyme and Microbial Technology

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The need for rapid, specific and sensitive assays that provide a detection of bacterial indicators are important for monitoring water quality. Rapid detection using biosensor is a novel approach for microbiological testing applications. Besides, validation of rapid methods is an obstacle in adoption of such new bio-sensing technologies. In this study, the strategy developed is based on using the compound 4-methylumbelliferyl glucuronide (MUG), which is hydrolyzed rapidly by the action of E. coli β-D-glucuronidase (GUD) enzyme to yield a fluorogenic product that can be quantified and directly related to the number of E. coli cells present in water samples.The detection time required for the biosensor response ranged from 30 to 120 minutes, depending on the number of bacteria. The specificity of the MUG based biosensor platform assay for the detection of E. coli was examined by pure cultures of non-target bacterial genera and also non-target substrates. GUD activity was found to be specific for E. coli and no such enzymatic activity was detected in other species. Moreover, the sensitivity of rapid enzymatic assays was investigated and repeatedly determined to be less than 10 E. coli cells per reaction vial concentrated from 100 mL of water samples.The applicability of the method was tested by performing fluorescence assays under pure and mixed bacterial flora in environmental samples. In addition, the procedural QA/QC for routine monitoring of drinking water samples have been validated by comparing the performance of the biosensor platform for the detection of E. coli and culture-based standard techniques such as Membrane Filtration (MF). The results of this study ii indicated that the fluorescence signals generated in samples using specific substrate molecules can be utilized to develop a bio-sensing platform for the detection of E. coli in drinking water. The procedural QA/QC of the biosensor will provide both industry and regulatory authorities a useful tool for near real-time monitoring of E. coli in drinking water samples. Furthermore, this system can be applied independently or in conjunction with other methods as a part of an array of biochemical assays in order to reliably detect E. coli in water.

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Section: Application Of Rapid Enzymatic Assays For Bacterial Detectionmentioning

confidence: 99%

A biosensor platform for rapid detection of E. coli in drinking water

Hesari

Alum

El-Zein

et al. 2016

Enzyme and Microbial Technology

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“…In the present study, we evaluated a rapid and simple enzyme based bioluminescence procedure for detection of coliform bacteria in drinking water (ColiLight). The enzyme b-D-galactosidase has been targeted in a range of colorimetric and fluorometric assays focusing on coliform bacteria in water and food (Apte et al 1995;Van Poucke and Nelis 1995;Geisler et al 2000;George et al 2001;Tryland et al 2001;Van Poucke and Nelis 2000). However, enzyme assays based on luminescence have the potential to be more sensitive than detection methods based on chromogenic of fluorogenic substrates (Bronstein et al 1989;Van Poucke and Nelis 1995;Masuda-Nishimura et al 2000).…”

Section: Discussionmentioning

confidence: 99%

“…Theoretically, one E. coli cell can easily divide and reach the detection limit for bioluminescence detection of b-D-galactosidase activity within 4 h. Hence, an enrichment time of 6-8 h should be sufficient to allow detection of E. coli and other coliforms with comparable b-D-galactosidase activity. An incubation time of 6 h or more has also been used in other assays for ''rapid detection'' of low-level concentrations of coliforms in environmental samples (Masuda-Nishimura et al 2000;Tryland et al 2001;Van Poucke and Nelis 2000;Serra et al 2005). Van Poucke and Nelis (2000) evaluated a range of enzymatic methods for detection of E. coli and other coliforms, and concluded that most methods requires at least 5.5-6.5 h for detection of indicator bacteria on membrane filters.…”

Section: Discussionmentioning

confidence: 99%

A simple bioluminescence procedure for early warning detection of coliform bacteria in drinking water

Bastholm

Wahlstrøm

Bjergbæk

et al. 2008

World J Microbiol Biotechnol

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Traditional cultivation-dependent tests for coliform bacteria in food and drinking water take 18-24 h to complete. Bioluminescence-based enzyme assays can potentially reduce analysis time for indicator bacteria such as coliforms. In the present study, we developed a simple presence/absence (P/A) bioluminescence procedure for rapid detection of coliform bacteria in groundwater-based drinking water. The bioluminescence procedure targeting b-D-galactosidase activity in coliform bacteria was based on hydrolysis of 6-O-b-galactopyranosyl-luciferin. Bacteria immobilized on membrane filters were enriched for 6-8 h in selective media containing isopropyl-b-D-thiogalactopyranoside (IPTG) to induce b-D-galactosidase activity in coliform bacteria. The equivalent of approximately 300 E. coli cells was required for bioluminescence detection of b-D-galactosidase activity. In comparison, PCR based detection of E. coli in drinking water required approximately 30 target cells. Analysis of contaminated drinking water samples showed comparable results for coliform bacteria using traditional multiple-tube fermentation, Colilert-18, and the bioluminescence procedure. Aeromonas hydrophila or indigenous groundwater bacteria did not interfere with the procedure. The bioluminescence procedure can be combined with commercial substrates such as Fluorocult or Colilert-18, and will allow the detection of one coliform in 100 ml drinking water within one working day. The results suggest the bioluminescence assays targeting b-D-galactosidase activity may be used for or for early warning screening of drinking water and/or rapid identification of contaminated drinking water wells.

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“…The sum of selective growth and GAL activity ensure the specificity of such methods [14]. By using sensitive instruments for detection of the end product, GAL activity can also often be measured directly in contaminated environmental water samples without pre-cultivation [15]. Such direct measurement of GAL activity in a water sample is not a measurement of culturable coliform bacteria, but of all enzymes (compounds that may hydrolyze the actual substrate) initially present in the water samples [12,16].…”

Section: Introductionmentioning

confidence: 99%

Monitoring of β-d-Galactosidase Activity as a Surrogate Parameter for Rapid Detection of Sewage Contamination in Urban Recreational Water

Tryland

Braathen

Wennberg

et al. 2016

Water

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Simple, automated methods are required for rapid detection of wastewater contamination in urban recreational water. The activity of the enzyme β-D-galactosidase (GAL) can rapidly (<2 h) be measured by field instruments, or a fully automated instrument, and was evaluated as a potential surrogate parameter for estimating the level of fecal contamination in urban waters. The GAL-activity in rivers, affected by combined sewer overflows, increased significantly during heavy rainfall, and the increase in GAL-activity correlated well with the increase in fecal indicator bacteria. The GAL activity in human feces (n = 14) was high (mean activity 7ˆ10 7 ppb MU/hour) and stable (1 LOG 10 variation), while the numbers of Escherichia coli and intestinal enterococci varied by >5 LOG 10 . Furthermore, the GAL-activity per gram feces from birds, sheep and cattle was 2-3 LOG 10 lower than the activity from human feces, indicating that high GAL-activity in water may reflect human fecal pollution more than the total fecal pollution. The rapid method can only be used to quantify high levels of human fecal pollution, corresponding to about 0.1 mg human feces/liter (or 10 3 E. coli/100 mL), since below this limit GAL-activity from non-fecal environmental sources may interfere.

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Early warning of faecal contamination of water: a dual mode, automated system for high- (<1 hour) and low-levels (6-11 hours)

Cited by 10 publications

References 0 publications

A biosensor platform for rapid detection of E. coli in drinking water

A biosensor platform for rapid detection of E. coli in drinking water

A simple bioluminescence procedure for early warning detection of coliform bacteria in drinking water

Monitoring of β-d-Galactosidase Activity as a Surrogate Parameter for Rapid Detection of Sewage Contamination in Urban Recreational Water

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