Inexpensive test detects E. coli in drinking water

Monitoring of bacteria concentrations is of great importance in drinking water management. Continuous real-time monitoring enables better microbiological control of the water and helps prevent contaminated water from reaching the households. We have developed a microfluidic sensor with the potential to accurately assess bacteria levels in drinking water in real-time. Multi frequency electrical impedance spectroscopy is used to monitor a liquid sample, while it is continuously passed through the sensor. We investigate three aspects of this sensor: First we show that the sensor is able to differentiate Escherichia coli (Gram-negative) bacteria from solid particles (polystyrene beads) based on an electrical response in the high frequency phase and individually enumerate the two samples. Next, we demonstrate the sensor’s ability to measure the bacteria concentration by comparing the results to those obtained by the traditional CFU counting method. Last, we show the sensor’s potential to distinguish between different bacteria types by detecting different signatures for S. aureus and E. coli mixed in the same sample. Our investigations show that the sensor has the potential to be extremely effective at detecting sudden bacterial contaminations found in drinking water, and eventually also identify them.

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Drinking water and diarrhoeal disease due to Escherichia coli

Journal of Water and Health ◽

10.2166/wh.2003.0008 ◽

2003 ◽

Vol 1 (2) ◽

pp. 65-72 ◽

Cited By ~ 49

Author(s):

Paul R. Hunter

Keyword(s):

Escherichia Coli ◽

Drinking Water ◽

Clinical Presentation ◽

Diarrhoeal Disease ◽

Central Place ◽

E Coli ◽

Related Disease ◽

Direct Damage ◽

Water Microbiology

Escherichia coli has had a central place in water microbiology for decades as an indicator of faecal pollution. It is only relatively recently that the role of E. coli as pathogen, rather than indicator, in drinking water has begun to be stressed. Interest in the role of E. coli as a cause of diarrhoeal disease has increased because of the emergence of E. coli O157:H7 and other enterohaemorrhagic E. coli, due to the severity of the related disease. There are enterotoxigenic, enteropathogenic, enterohaemorrhagic, enteroinvasive, enteroaggregative and diffusely adherent strains of E. coli. Each type of E. coli causes diarrhoeal disease through different mechanisms and each causes a different clinical presentation. Several of the types cause diarrhoea by the elaboration of one or more toxins, others by some other form of direct damage to epithelial cells. This paper discusses each of these types in turn and also describes their epidemiology, with particular reference to whether they are waterborne or not.

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Spread of Antibiotic Resistance in Aquatic Environments: E. coli as a Case Study

Proceedings ◽

10.3390/proceedings2110693 ◽

2018 ◽

Vol 2 (11) ◽

pp. 693 ◽

Cited By ~ 1

Author(s):

Maria Adamantia Efstratiou ◽

Marina Bountouni ◽

Efthimios Kefalas

Keyword(s):

Escherichia Coli ◽

Drinking Water ◽

Antibiotic Resistance ◽

Rural Communities ◽

Ground Water ◽

Aquatic Environments ◽

Multiple Resistance ◽

E Coli ◽

Of Greece

The aim of this study was to gather information on the spread of antibiotic resistance in Escherichia coli isolates from wells, boreholes and untreated drinking water in islands of Greece. We analyzed for antibiotic resistance 235 E. coli strains isolated from untreated drinking water of small rural communities, and ground water from 4 islands. Resistance was tested against Norfloxacin, Ciprofloxacin, Levofloxacin, Amoxicillin and Cefaclor. More than half (54.9%) were resistant to at least one of the antibiotics tested. Of these 26.3% showed multiple resistance (to two or more antibiotics). Strains from drinking water sources were overall more sensitive. Frequent resistance was observed for Amoxicillin (38.3%) and Levofloxacin (28.5%), low for Norfloxacin (5.5%).

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Assessment of the Risk Associated with E. coli Bacterial Intrusion in Drinking Water Distribution Networks

Arabian Journal for Science and Engineering ◽

10.1007/s13369-018-3344-6 ◽

2018 ◽

Vol 44 (5) ◽

pp. 4161-4168

Author(s):

Ashraf Farahat ◽

Mohammed T. Mahmoud ◽

Amjad Khalil

Keyword(s):

Drinking Water ◽

Water Distribution ◽

Distribution Networks ◽

Water Distribution Networks ◽

E Coli ◽

Drinking Water Distribution

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Identification and management of microbial contaminations in a surface drinking water source

Journal of Water and Health ◽

10.2166/wh.2007.137 ◽

2007 ◽

Vol 5 (S1) ◽

pp. 67-79 ◽

Cited By ~ 12

Author(s):

J. Åström ◽

T. J. R. Pettersson ◽

T. A. Stenström

Keyword(s):

Drinking Water ◽

Water Intake ◽

Surface Waters ◽

Microbial Contamination ◽

Water Source ◽

Drinking Water Source ◽

Raw Water ◽

Indicator Organisms ◽

E Coli ◽

The City

Microbial contamination of surface waters constitutes a health risk for drinking water consumers which may be lowered by closing the raw water intake. We have evaluated microbial discharge events reported in the river Göta älv, which is used for raw water supply to the city of Göteborg. Elevated levels of faecal indicator bacteria were observed during periods of closed raw water intake. High bacteria levels were, however, also occasionally detected during periods of open intake, probably as a result of microbial discharge far upstream in the river which may be difficult to predict and manage by closing the intake. Accumulated upstream precipitations, resulting in surface runoff and wastewater contaminations in the catchment, correlated positively with the levels of total coliforms, E. coli, intestinal enterococci and sulfite-reducing clostridia. Levels of faecal indicator organisms were negatively correlated to the water temperature due to enhanced survival at lower temperatures. Wastewater discharges from a municipality located just upstream of the water intake resulted in elevated E. coli concentrations downstream at the raw water intake for Göteborg. To improve the prediction of microbial contaminations within the river Göta älv, monitoring data on turbidity and upstream precipitation are of particular importance.

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Development of an Internal Control for Evaluation and Standardization of a Quantitative PCR Assay for Detection of Helicobacter pylori in Drinking Water

Applied and Environmental Microbiology ◽

10.1128/aem.00687-07 ◽

2007 ◽

Vol 73 (22) ◽

pp. 7380-7387 ◽

Cited By ~ 20

Author(s):

Keya Sen ◽

Nancy A. Schable ◽

Dennis J. Lye

Keyword(s):

Helicobacter Pylori ◽

Drinking Water ◽

Quantitative Pcr ◽

Water Samples ◽

Sodium Thiosulfate ◽

Qpcr Assay ◽

E Coli ◽

H Pylori ◽

Labeled Probe ◽

Treated Drinking Water

ABSTRACT Due to metabolic and morphological changes that can prevent Helicobacter pylori cells in water from growing on conventional media, an H. pylori-specific TaqMan quantitative PCR (qPCR) assay was developed that uses a 6-carboxyfluorescein-labeled probe (A. E. McDaniels, L. Wymer, C. Rankin, and R. Haugland, Water Res. 39:4808-4816, 2005). However, proper internal controls are needed to provide an accurate estimate of low numbers of H. pylori in drinking water. In this study, the 135-bp amplicon described by McDaniels et al. was modified at the probe binding region, using PCR mutagenesis. The fragment was incorporated into a single-copy plasmid to serve as a PCR-positive control and cloned into Escherichia coli to serve as a matrix spike. It was shown to have a detection limit of five copies, using a VIC dye-labeled probe. A DNA extraction kit was optimized that allowed sampling of an entire liter of water. Water samples spiked with the recombinant E. coli cells were shown to behave like H. pylori cells in the qPCR assay. The recombinant E. coli cells were optimized to be used at 10 cells/liter of water, where they were shown not to compete with 5 to 3,000 cells of H. pylori in a duplex qPCR assay. Four treated drinking water samples spiked with H. pylori (100 cells) demonstrated similar cycle threshold values if the chlorine disinfectant was first neutralized by sodium thiosulfate.

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