scholarly journals Quantitative real-time PCR does not reliably detect single fecal indicator bacteria in drinking water

2016 ◽  
Vol 16 (6) ◽  
pp. 1674-1682 ◽  
Author(s):  
Tamara Krapf ◽  
Roger Michael Kuhn ◽  
Peter Kauf ◽  
Corinne Helene Gantenbein-Demarchi ◽  
Lars Fieseler
Keyword(s):  
Drinking Water ◽  
Membrane Filtration ◽  
Limit Of Detection ◽  
Fecal Indicator Bacteria ◽  
Quantitative Polymerase Chain Reaction ◽  
Indicator Bacteria ◽  
Microbial Quality ◽  
Fecal Indicator ◽  
Cell Counts

The microbial quality of drinking and environmental water is usually determined by culture-based detection of fecal indicator bacteria according to ISO reference methods 16649-1 and 7899-2, respectively. Because of an increasing demand for rapid, culture-independent methods, we tested three quantitative polymerase chain reaction (qPCR) approaches for the simultaneous detection of both, Escherichia coli and Enterococcus spp., using either 16S rRNA or 16S rDNA as a target molecule. Filter sterilized drinking water was artificially contaminated with bacteria from either high or low nutrient culture conditions and directly analyzed after membrane filtration without any other enrichment. Depending on the culture condition used, qPCR analyses revealed a lower limit of detection of 1–10 E. coli/100 ml and 10–100 E. faecalis/100 ml, respectively. In addition, the microbial quality of different surface water samples was monitored. The analyses revealed a clear correlation between viable cell counts and qPCR data. However, the safe and reliable detection of 1 CFU/100 ml failed.

scholarly journals Fecal Indicator Bacteria Data to Characterize Drinking Water Quality in Low-Resource Settings: Summary of Current Practices and Recommendations for Improving Validity

2021 ◽  
Vol 18 (5) ◽  
pp. 2353
Author(s):  
Mustafa Sikder ◽  
Elena N. Naumova ◽  
Anthonia O. Ogudipe ◽  
Mateo Gomez ◽  
Daniele Lantagne
Keyword(s):  
Drinking Water ◽  
Statistical Methods ◽  
Membrane Filtration ◽  
Statistical Tests ◽  
Fecal Indicator Bacteria ◽  
Indicator Bacteria ◽  
Fecal Indicator ◽  
Middle Income ◽  
Evidence Quality ◽  
Disease Risks

Fecal indicator bacteria (FIB) values are widely used to assess microbial contamination in drinking water and to advance the modeling of infectious disease risks. The membrane filtration (MF) testing technique for FIB is widely adapted for use in low- and middle-income countries (LMICs). We conducted a systematic literature review on the use of MF-based FIB data in LMICs and summarized statistical methods from 172 articles. We then applied the commonly used statistical methods from the review on publicly available datasets to illustrate how data analysis methods affect FIB results and interpretation. Our findings indicate that standard methods for processing samples are not widely reported, the selection of statistical tests is rarely justified, and, depending on the application, statistical methods can change risk perception and present misleading results. These results raise concerns about the validity of FIB data collection, analysis, and presentation in LMICs. To improve evidence quality, we propose a FIB data reporting checklist to use as a reminder for researchers and practitioners.

MColiPAT kit for early detection of coliforms in water

2020 ◽  
Vol 20 (3) ◽  
pp. 871-877
Author(s):  
Ashish Tambi ◽  
Urmila Brighu ◽  
A. B. Gupta
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Low Cost ◽  
Water Quality Assessment ◽  
Indicator Bacteria ◽  
Microbial Quality ◽  
Trained Personnel ◽  
Microbiological Water Quality ◽  
Rapid Tests

Abstract Determining the microbial quality of drinking water by assessing the presence/absence (P/A) or enumeration of indicator bacteria continues to be widely practiced worldwide. However, rapid tests are required for microbiological water quality assessment so that the information is available in the shortest possible time for initiating a timely intervention. Traditional methods for the enumeration of indicator bacteria are not only expensive but also need trained personnel. We have developed a low-cost kit, MColiPAT, and have validated its application for detection of coliforms in drinking water using the IDEXX Colilert-18 Quanti tray method. MColiPAT kit medium was able to detect coliforms down to a level of 3.1 MPN/100 ml within 10.5 hours. The sensitivity and specificity of the kit were 95.45% and 100% respectively. MColiPAT is found to be reliable and accurate for the detection of coliforms in drinking water.

scholarly journals Influence of wastewater disinfection on densities of culturable fecal indicator bacteria and genetic markers

2013 ◽  
Vol 12 (3) ◽  
pp. 410-417 ◽  
Author(s):  
Eunice C. Chern ◽  
Kristen Brenner ◽  
Larry Wymer ◽  
Richard A. Haugland
Keyword(s):  
Genetic Marker ◽  
Genetic Markers ◽  
Environmental Protection Agency ◽  
Fecal Indicator Bacteria ◽  
Quantitative Polymerase Chain Reaction ◽  
Indicator Bacteria ◽  
Fecal Indicator ◽  
The Us ◽  
Wastewater Disinfection ◽  
Different Seasons

The US Environmental Protection Agency has proposed the use of quantitative polymerase chain reaction (qPCR) as a rapid alternative analytical method for monitoring recreational water quality at beaches. For qPCR to be considered for other Clean Water Act purposes, such as inclusion in discharge permits and use in Total Maximum Daily Load calculations, it is necessary to understand how qPCR detectable genetic markers are influenced by wastewater disinfection. This study investigated genetic markers for Escherichia coli, Enterococcus, Clostridium spp., Bacteroides, total Bacteroidales, as well as the human-associated Bacteroides markers, HF183 and HumM2, to determine which, if any, were influenced by disinfection (chlorination or ultraviolet light) of effluents from secondary wastewater treatment in different seasons. The effects of disinfection on culturable enterococci, E. coli, Bacteroides, and C. perfringens were also compared to their associated genetic markers. Disinfection of secondary treatment effluents significantly reduced culturable fecal indicator bacteria (FIB) but not genetic marker densities. No significant differences were observed in the responses of FIB culture and genetic marker densities to type of disinfection (chlorination vs UV) or season. Results of this study provide evidence that qPCR may not be suitable for monitoring efficacy of wastewater disinfection on the inactivation of bacterial pathogens.

scholarly journals Springing for Safe Water: Drinking Water Quality and Source Selection in Central Appalachian Communities

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 888 ◽  
Author(s):  
Hannah Patton ◽  
Leigh-Anne Krometis ◽  
Emily Sarver
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Tap Water ◽  
Fecal Indicator Bacteria ◽  
The United States ◽  
Spring Water ◽  
Indicator Bacteria ◽  
Drinking Water Source ◽  
Fecal Indicator ◽  
Source Selection

Issues surrounding water infrastructure, access, and quality are well documented in the Central Appalachian region of the United States. Even in cases where residents have in-home piped point-of-use (POU) water, some rely on alternative drinking water sources for daily needs—including water collection from roadside springs. This effort aims to better understand and document spring usage in this region by identifying the factors that influence drinking water source selection and comparing household and spring water quality to Safe Drinking Water Act (SDWA) health-based and aesthetic contaminant recommendations. Households were recruited from communities surrounding known springs in three states (Kentucky, Virginia, and West Virginia). First- and second-draw, in-home POU tap water samples were collected from participating households and compared to samples collected from local springs on the same day. Samples were analyzed for fecal indicator bacteria and inorganic ions. Study participants completed surveys to document perceptions of household drinking water and typical usage. The majority of survey participants (82.6%) did not trust their home tap water due to aesthetic issues. Water quality results suggested that fecal indicator bacteria were more common in spring water, while several metallic ions were recovered in higher concentrations from household samples. These observations highlight that health risks and perceptions may be different between sources.

scholarly journals Microbiological Assessment of Tap Water Following the 2016 Louisiana Flooding

2020 ◽  
Vol 17 (4) ◽  
pp. 1273 ◽  
Author(s):  
Nati K. Phan ◽  
Samendra P. Sherchan
Keyword(s):  
Baton Rouge ◽  
Tap Water ◽  
Fecal Indicator Bacteria ◽  
Quantitative Polymerase Chain Reaction ◽  
Indicator Bacteria ◽  
Physical Parameters ◽  
Fecal Indicator ◽  
E Coli ◽  
Adverse Health Outcomes ◽  
Oxidation Reduction

Floods are a prominent risk factor in the world of public health, as there is a risk of dispersal of harmful biological and chemical contaminants in floodwater. As climate change increases, the occurrence of natural disasters and risk of adverse health outcomes due to flash flooding also increases. Fecal indicator bacteria, such as Escherichia coli and Enterococci, are often encountered in contaminated floodwater and can cause gastrointestinal illnesses as well as a variety of infections. In August 2016, East Baton Rouge and surrounding parishes in Louisiana suffered heavy floods due to intense rainfall. No study of water quality during flooding has been conducted previously in Baton Rouge, Louisiana. Twenty-three pre-flush and post-flush water samples were collected immediately from accessible homes that had been affected by the floods in order to quantify concentrations of fecal indicator bacteria. These samples were analyzed for the presence of E. coli and Enterococci through both quantitative polymerase chain reaction (qPCR) and the IDEXX enzyme substrate method. The qPCR results indicated that 30% of the samples contained Enterococci and 61% of the samples contained E. coli, with the highest concentrations found in the pre-flush outdoor hose and the pre-flush kitchen tap. The IDEXX method yielded total coliforms in 65% of the samples, E. coli in 4%, and Enterococci in 35%, with the highest concentrations in the pre-flush outdoor faucet and the pre-flush post-filtration kitchen tap. Physical parameters including temperature, barometer pressure, dissolved oxygen, oxidation reduction potential, pH, conductivity, and salinity of these samples were also recorded. Of these parameters, conductivity and salinity were significant, suggesting they may positively influence E. coli and Enterococci growth.

scholarly journals Correlation among fecal indicator bacteria and physicochemical parameters with the presence ofHelicobacter pyloriDNA in raw and drinking water from Bogotá, Colombia

Helicobacter ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. e12582 ◽  
Author(s):  
Fidson‐Juarismy Vesga ◽  
Yolanda Moreno ◽  
María Antonia Ferrús ◽  
Lina María Ledesma‐Gaitan ◽  
Claudia Campos ◽  
...  
Keyword(s):  
Drinking Water ◽  
Physicochemical Parameters ◽  
Fecal Indicator Bacteria ◽  
Indicator Bacteria ◽  
Fecal Indicator

scholarly journals Monitoring Waterborne Pathogens in Surface and Drinking Waters. Are Water Treatment Plants (WTPs) Simultaneously Efficient in the Elimination of Enteric Viruses and Fecal Indicator Bacteria (FIB)?

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2824
Author(s):  
Daniel Salvador ◽  
Maria Filomena Caeiro ◽  
Fátima Serejo ◽  
Paulo Nogueira ◽  
Rui Neves Carneiro ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Surface Water ◽  
Hepatitis A Virus ◽  
Fecal Indicator Bacteria ◽  
Enteric Viruses ◽  
Viral Rna ◽  
Indicator Bacteria ◽  
Fecal Indicator ◽  
Water Treatment Plants

Monitoring the quality of water is a requisite to prevent outbreaks related to waterborne diseases, predominantly caused by pathogens like enteric viruses, usually transmitted via the fecal-oral route. This study aimed to survey a group of enteric viruses (Enterovirus, Norovirus genogroups I and II, and hepatitis A virus) in two surface water sources of drinking water, also intending to evaluate the extent of their elimination in the two water treatment plants (WTPs) involved in drinking water production. Correlations between these viruses and fecal indicator bacteria (FIB) were also evaluated. Positive samples for viral RNA were recurrently found by reverse transcription quantitative PCR (RT-qPCR) and quantified, in genomic copies per liter (gc/L) of sampled water. Viral RNAs were detected in 14 out of 27 samples of surface water, and 21 out of 36 samples of drinking water, NoV II having been the most frequently detected in both (0–78.6 gc/L and 0–12.5 gc/L, respectively). Both WTPs showed variable efficacies in the elimination of viral RNA. Only one correlation was found with FIB, between NoV II and intestinal enterococci. These results recommend the monitoring of enteric viruses over time and their inclusion in the mandatory analysis of water quality.

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