scholarly journals Microbial Source Tracking Markers for Detection of Faecal Contamination in Environmental Waters

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Asima Zehra
Keyword(s):  
Microbial Source Tracking ◽  
Source Tracking ◽  
Environmental Waters ◽  
Faecal Contamination

scholarly journals Assessment of source tracking methods for application in spring water

2014 ◽  
Vol 13 (2) ◽  
pp. 473-488 ◽  
Author(s):  
Melanie Wicki ◽  
Adrian Auckenthaler ◽  
Richard Felleisen ◽  
Fatma Karabulut ◽  
Isabel Niederhauser ◽  
...  
Keyword(s):  
Surface Water ◽  
Scientific Literature ◽  
Microbial Source Tracking ◽  
Spring Water ◽  
Source Tracking ◽  
Animal Waste ◽  
Faecal Contamination ◽  
Potential Source ◽  
Host Strains

For discriminating between human and animal faecal contamination in water, microbial source tracking (MST) approaches using different indicators have been employed. In the current study, a range of 10 such MST indicators described in the scientific literature were comparatively assessed. Bacteriophages infecting host strains of Bacteroides (GA-17, GB-124 and ARABA 84) as well as sorbitol-fermenting bifidobacteria proved useful for indicating human faecal contamination while Rhodococcus coprophilus was associated with animal-derived faecal contamination. These potential source indicators were present in samples of faecal origin, i.e. either in human wastewater or animal waste, from many different regions in Switzerland and therefore showed a geographic stability. In addition, the MST indicators were abundant in surface water and were even sensitive enough to detect faecal contamination in spring water from two study areas in Switzerland. This is the first study that has compared and successfully applied MST methods in spring water.

scholarly journals Performance of Two Quantitative PCR Methods for Microbial Source Tracking of Human Sewage and Implications for Microbial Risk Assessment in Recreational Waters

2012 ◽  
Vol 78 (20) ◽  
pp. 7317-7326 ◽  
Author(s):  
Christopher Staley ◽  
Katrina V. Gordon ◽  
Mary E. Schoen ◽  
Valerie J. Harwood
Keyword(s):  
Risk Assessment ◽  
Quantitative Pcr ◽  
Microbial Source Tracking ◽  
Human Polyomavirus ◽  
Source Tracking ◽  
Specific Marker ◽  
Environmental Waters ◽  
Potential Health ◽  
Microbial Risk Assessment ◽  
Microbial Risk

ABSTRACTBefore new, rapid quantitative PCR (qPCR) methods for assessment of recreational water quality and microbial source tracking (MST) can be useful in a regulatory context, an understanding of the ability of the method to detect a DNA target (marker) when the contaminant source has been diluted in environmental waters is needed. This study determined the limits of detection and quantification of the human-associatedBacteroidessp. (HF183) and human polyomavirus (HPyV) qPCR methods for sewage diluted in buffer and in five ambient, Florida water types (estuarine, marine, tannic, lake, and river). HF183 was quantifiable in sewage diluted up to 10−6in 500-ml ambient-water samples, but HPyVs were not quantifiable in dilutions of >10−4. Specificity, which was assessed using fecal composites from dogs, birds, and cattle, was 100% for HPyVs and 81% for HF183. Quantitative microbial risk assessment (QMRA) estimated the possible norovirus levels in sewage and the human health risk at various sewage dilutions. When juxtaposed with the MST marker detection limits, the QMRA analysis revealed that HF183 was detectable when the modeled risk of gastrointestinal (GI) illness was at or below the benchmark of 10 illnesses per 1,000 exposures, but the HPyV method was generally not sensitive enough to detect potential health risks at the 0.01 threshold for frequency of illness. The tradeoff between sensitivity and specificity in the MST methods indicates that HF183 data should be interpreted judiciously, preferably in conjunction with a more host-specific marker, and that better methods of concentrating HPyVs from environmental waters are needed if this method is to be useful in a watershed management or monitoring context.

An optimized enumeration method for sorbitol-fermenting Bifidobacteria in water samples

2005 ◽  
Vol 51 (5) ◽  
pp. 413-422 ◽  
Author(s):  
Sharon C Long ◽  
Catalina Arango P. ◽  
Jeanine D Plummer
Keyword(s):  
Membrane Filtration ◽  
Fecal Contamination ◽  
Domestic Wastewater ◽  
Microbial Source Tracking ◽  
Quantitative Information ◽  
Source Tracking ◽  
Human Consumption ◽  
Bromocresol Purple ◽  
Environmental Waters ◽  
Biochemical Tests

With increased focus on watershed protection under the Surface Water Treatment Rule, indicators that discriminate among sources of microbial inputs (microbial source tracking) are needed to supplement the quantitative information provided by total and fecal coliform measurements for drinking water monitoring. Bifidobacteria are found in the digestive tract and feces of humans and other animals, and also in sewage. Sorbitol is a food additive used exclusively in food intended for human consumption. Therefore, the presence of sorbitol-fermenting Bifidobacteria in environmental waters can be indicative of sources of human fecal contamination. A series of media were evaluated using ATCC cultures of B. breve and B. adolescentis, feces from different animals, and domestic wastewater samples. The media evaluated were Human Bifid Sorbitol agar (HBSA), modified Human Bifid Sorbitol agar, Beerens Medium, modified Beerens Medium, Reinforced Clostridial agar, BIM-25 Medium, and modified BIM-25 Medium. Variables such as sample preservation, incubation time, different pH indicators, plating technique, and discontinuous exposure to sorbitol were also evaluated. A series of biochemical tests were used to confirm positive colonies enumerated on the various media. Membrane filtration and enumeration of sodium sulfite preserved samples on HBSA containing bromocresol purple using loose lidded plates for 48 h provided the best recoveries for presumptive positive colonies. A number of sorbitol-fermenters that were not Bifidobacteria were able to grow on all media tested, resulting in false-positives. Therefore, plating on HBSA should be followed by a confirmation step when monitoring for sorbitol-fermenting Bifidobacteria in environmental waters. A year-long sampling survey of a managed reservoir in Massachusetts provided field validation of the proposed methodology for sorbitol-fermenting Bifidobacteria as a human-related source tracking indicator tool.Key words: sorbitol-fermenting Bifidobacteria, microbial source tracking, watershed management, fecal contamination.

Experience with the antibiotic resistance analysis and DNA fingerprinting in tracking faecal pollution at two lake beaches

2007 ◽  
Vol 56 (11) ◽  
pp. 51-58 ◽  
Author(s):  
T.A. Edge ◽  
S. Hill ◽  
G. Stinson ◽  
P. Seto ◽  
J. Marsalek
Keyword(s):  
Antibiotic Resistance ◽  
Dna Fingerprinting ◽  
Microbial Source Tracking ◽  
Source Tracking ◽  
Faecal Contamination ◽  
E Coli ◽  
Resistance Analysis ◽  
Antibiotic Resistance Analysis ◽  
Environmental Challenge ◽  
Made In

Posting or closing of swimming beaches because of faecal contamination is a widespread problem reported in many locations. In a risk-based approach to this problem, the risk to swimmers' health is assessed by field monitoring of indicator bacteria and the associated risks are managed by source controls and other remedial measures. In risk assessment, great advances have been made in recent years with the introduction of microbial source tracking (MST) techniques. Two such techniques, antibiotic resistance analysis and DNA fingerprinting, were applied in a study of causes of faecal contamination at two lake beaches in Toronto, Ontario. Both methods identified bird faeces as the dominant sources of E. coli. Coping with this type of pollution presents a major environmental challenge.

scholarly journals Estimation of pathogen concentrations in a drinking water source using hydrodynamic modelling and microbial source tracking

2012 ◽  
Vol 10 (3) ◽  
pp. 358-370 ◽  
Author(s):  
Ekaterina Sokolova ◽  
Johan Åström ◽  
Thomas J. R. Pettersson ◽  
Olof Bergstedt ◽  
Malte Hermansson
Keyword(s):  
Drinking Water ◽  
Fate And Transport ◽  
Water Source ◽  
Microbial Source Tracking ◽  
Water Sources ◽  
Source Tracking ◽  
Drinking Water Source ◽  
Faecal Contamination ◽  
Contamination Sources ◽  
Drinking Water Sources

The faecal contamination of drinking water sources can lead to waterborne disease outbreaks. To estimate a potential risk for waterborne infections caused by faecal contamination of drinking water sources, knowledge of the pathogen concentrations in raw water is required. We suggest a novel approach to estimate pathogen concentrations in a drinking water source by using microbial source tracking data and fate and transport modelling. First, the pathogen (norovirus, Cryptosporidium, Escherichia coli O157/H7) concentrations in faecal contamination sources around the drinking water source Lake Rådasjön in Sweden were estimated for endemic and epidemic conditions using measured concentrations of faecal indicators (E. coli and Bacteroidales genetic markers). Afterwards, the fate and transport of pathogens within the lake were simulated using a three-dimensional coupled hydrodynamic and microbiological model. This approach provided information on the contribution from different contamination sources to the pathogen concentrations at the water intake of a drinking water treatment plant. This approach addresses the limitations of monitoring and provides data for quantitative microbial risk assessment (QMRA) and risk management in the context of faecal contamination of surface drinking water sources.

scholarly journals Application of library-independent microbial source tracking methods for identifying the sources of faecal contamination in coastal areas

2010 ◽  
Vol 61 (6) ◽  
pp. 1401-1409 ◽  
Author(s):  
M. Gourmelon ◽  
M. P. Caprais ◽  
C. Le Mennec ◽  
S. Mieszkin ◽  
C. Ponthoreau ◽  
...  
Keyword(s):  
Water Samples ◽  
Microbial Source Tracking ◽  
Coastal Areas ◽  
Source Tracking ◽  
Rrna Gene ◽  
Multiple Sources ◽  
Gene Markers ◽  
Faecal Contamination ◽  
Water Courses ◽  
Specific Bacteriophage

Faecal contamination sources were identified in coastal areas around the Guerande-Atlantique peninsula using two microbial source tracking (MST) methods: (i) Bacteroidales host-specific 16S rRNA gene markers measured by real-time PCR and (ii) F-specific bacteriophage (FRNAPH) genotyping. Both methods were used on 63 water samples from 7 water courses. HF183 marker and bacteriophage genogroup II (FRNAPH II) were detected in all water samples and in the majority of water samples, respectively, from La Torre stream (W5), Piriac (W2), R2000 (W3) and Mazy (W7) rain water drains, and also detected, less frequently, in Le Nau drain (W4), suggesting contamination by human faecal sources at these sites. These human markers were weakly detected in Pouliguen channel (W6). Furthermore, BacR and bacteriophage genogroup I (FRNAPH I) were also detected, but at lower concentration and frequency. So, site W6 seems to be contaminated by multiple sources, though mainly human. Finally, BacR was detected twice in Pont d'Armes channel (W1), whereas HF183 was not detected. FRNAPH I and II were detected in only 3 out of 12 water samples. Site W1 seems mainly contaminated by animal sources. As a result of our findings, actions were taken to remediate water and shellfish quality.

Library-dependent and library-independent microbial source tracking to identify spatial variation in faecal contamination sources along a Lake Ontario beach (Ontario, Canada)

2010 ◽  
Vol 62 (3) ◽  
pp. 719-727 ◽  
Author(s):  
T. A. Edge ◽  
S. Hill ◽  
P. Seto ◽  
J. Marsalek
Keyword(s):  
Spatial Variation ◽  
Municipal Wastewater ◽  
Lake Ontario ◽  
Microbial Source Tracking ◽  
Pollution Sources ◽  
Source Tracking ◽  
Faecal Contamination ◽  
E Coli ◽  
Faecal Pollution ◽  
Humber River

Multiple microbial source tracking methods were applied to investigate spatial variation in faecal pollution sources impacting a 1.7 km freshwater beach on Lake Ontario (Canada). The highest E. coli concentrations measured in the study area were from interstitial sand pore water at Sunnyside Beach, reaching 2.6 × 106 CFU/100 ml. These E. coli concentrations exceeded those in the nearby Humber River and Black Creek, which are impacted by combined sewer overflows containing municipal wastewater and by stormwater conveying washoff from the urban area. Library-independent Bacteroidales HF183 analyses identified the more frequent occurrence of municipal wastewater contamination in the Humber River and at a Sunnyside Beach location closest to the mouth of the river. Library-dependent E. coli antibiotic resistance and rep-PCR DNA fingerprinting analyses identified the more frequent occurrence of bird faecal contamination at Sunnyside Beach locations away from the river mouth. These microbial source tracking results raise caution about managing beaches with multiple sources of contamination as a single entity without considering spatial variability in faecal pollution sources and the need for more localized beach management practices.

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