Diurnal variability in concentrations and sources of Escherichia coli in three streams

2006 ◽  
Vol 52 (11) ◽  
pp. 1130-1135 ◽  
Author(s):  
Cindy L Meays ◽  
Klaas Broersma ◽  
Rick Nordin ◽  
Asit Mazumder ◽  
Mansour Samadpour

Microbial contamination is a major concern for drinking water worldwide. Many monitoring protocols that use one or very few samples are inadequate and introduce a very large margin of error. An intensive sampling program needs to be conducted to characterize the Escherichia coli concentrations of a source water stream prior to establishing a monitoring program so that the sample frequency can be determined statistically, based on an acceptable margin of error. Developing meaningful monitoring programs for managing bacterial water quality is dependant on scientific data that determine the bacterial sources. In this study, three streams from drinking water watersheds were sampled every 15 min over a 24 h period on three different days to determine the concentrations of E. coli and to identify their sources, using ribosomal RNA finger printing (ribotyping). The concentrations of E. coli varied throughout the day in each of the three streams. Ribotyping identified many different animal sources of E. coli in the samples. The sources of E. coli varied significantly with stream (P < 0.001, df = 16). The development of monitoring programs for watersheds needs to consider the watershed, and care needs to be taken in selecting appropriate sample sites, sampling regime, and number of samples taken during each sampling period. This note provides a prescription for the development of monitoring programs for watersheds.Key words: Escherichia coli, fecal bacteria, water quality, ribotyping, source tracking, microbial source tracking, bacterial source tracking.

2021 ◽  
Vol 99 (12) ◽  
pp. 1353-1359
Author(s):  
Angelika V. Zagainova ◽  
Galina M. Trukhina ◽  
Yury A. Rakhmanin ◽  
Tamara Z. Artemova ◽  
Marina A. Sukhina

Introduction. The increasing bacterial contamination of water bodies requires an increase in water quality control’s reliability to ensure epidemic safety against waterborne infections. Therefore, researchers in both Russia and Europe came to the conclusion that it is necessary to search for indicator microorganisms that can more accurately suggest the presence of pathogens. microorganisms in water than traditional indicators. The aim of the study was to justify the introduction of indicator indices of fecal contamination “generalized coliform bacteria” and Escherichia coli to assess the safety of drinking water Material and methods. The article provides an analysis of domestic and international regulatory documents and literary materials regulating the quality of drinking water in terms of sanitary and microbiological indicators and assessment criteria. The results of many years of experimental and field research carried out by research organizations and practical organizations of the Federal Service for Supervision of Consumer Rights Protection and Human Welfare are presented. Results. On the territory of Russia, “general coliform bacteria,” is one of the indicator indices chosen according to the fermentation of lactose, determine the safety of drinking water. The water does not take into account pathogenic bacteria (Salmonella, Shigella) and a number of lactose-negative opportunistic bacteria, causative agents of intestinal infections. The study of microorganisms isolated from the feces of patients confirms the frequency of occurrence of lactose-negative microorganisms to varying from 20 to 100% of strains. With an annual trend towards a decrease in the percentage of non-standard drinking water samples in terms of microbiological indices, general intestinal infections (GII) of unknown etiology increase, i.e. risk of GII. If the quality of drinking water does not correspond to thermotolerant coliform bacteria (TCB), 95% of samples contain E. coli. Therefore, the determination of E. coli more reliably indicates the intake of fresh fecal contamination and provides efficiency in taking measures to eliminate an unfavorable situation than TCB. Conclusion. Reasons are given for the introduction of more reliable microbiological indicators of water safety control, such as - “generalized coliform bacteria” with the preservation of the abbreviation GCB, combining both lactose-positive and lactose-negative bacteria, determined by the sign of glucose fermentation, negative oxidase test and negative stain according to Gram and E. coli as an indicator of recent faecal contamination, which will allow the assessment of water quality for a wide range of bacteria of the order Enterobacterials, corresponding to the modern taxonomy of Enterobacteriaceae NCBI, will ensure harmonization with international requirements and the safety of drinking water for the population.


Author(s):  
Farhan Mohammad Khan ◽  
Rajiv Gupta

Escherichia coli or E. coli is a member of the fecal coliform group and is a more specific indicator of fecal contamination than other fecal coliform species, its presence indicate possibly presence of harmful bacteria which will cause diseases and it also suggests the extent as well as the nature of the contaminants. E. coli bacteria able to survive in water for 4 &ndash; 12 weeks and at present, it appears as an indicator to provide the accurate bacterial contamination of fecal matter in drinking water, because of the availability of simple, affordable, fast, sensitive and exact detection techniques. According to the laboratory experiment based techniques, 24 - 48 hours are required for the bacterial concentration to be reported. So, there is a necessity for continuous monitoring. Techniques for detection of many pathogenic bacterial strains are not yet available, sometimes days to weeks are required to get the results. To overcome the difficulties, expensive and time-consuming techniques are required to detect, count and identify the presence of specific bacterial strain. Public health relies on online monitoring of water quality that depends majorly on examination of fecal indicator bacteria, thus protection of health requires fecal pollution indicator so that it is not required to analyze drinking water to overcome the problems associated with waterborne diseases. This paper will brief the classification, sources, survival of E. coli bacteria and its correlation with basic water quality parameters in water sources.```


2013 ◽  
Vol 79 (19) ◽  
pp. 5799-5813 ◽  
Author(s):  
T. A. Edge ◽  
I. U. H. Khan ◽  
R. Bouchard ◽  
J. Guo ◽  
S. Hill ◽  
...  

ABSTRACTThe occurrence of waterborne pathogens was investigated at three drinking water intakes located about 2 km offshore in Lake Ontario. Water sampling was conducted over 3 years forCampylobacterspp.,Cryptosporidiumspp.,Giardiaspp., cultivable enteric viruses, and water quality parameters. All pathogens were detected in the offshore source water for each water treatment plant (WTP1 to WTP3), although at relatively low frequencies and concentrations.Giardiawas the most common pathogen, occurring in 36% of water samples from the influent of WTP1 (n= 46), and with a maximum concentration of 0.70 cysts/liter in this influent.Cryptosporidiumoccurred as frequently as 15% in the WTP2 influent (n= 35), with a maximum concentration of 0.40 oocysts/liter in the WTP1 influent. The humanBacteroidalesHF183 DNA marker was most common in the WTP1 influent (19%), and this was the only WTP where theCryptosporidium hominisgenotype was detected. No water quality parameter was predictive of pathogen occurrence across all three WTP influents.Escherichia coliwas often below detection when pathogens were detected, and spikes inE. coliconcentrations often did not coincide with pathogen occurrence. After summer rain events, river plumes hadE. coliconcentrations as high as 222 CFU/100 ml in surface waters 2 km offshore, without impacting drinking water intakes below the thermocline on the lake bottom. At times, prechlorination to control mussels at offshore intake cribs compromised the use ofE. colifor “raw” water quality assessment, particularly for chlorine-resistantCryptosporidium. E. colimeasured by standard methods did not reliably predict pathogen occurrence at drinking water intakes in offshore ecosystems.


Author(s):  
Azwar Azwar ◽  
Safrida Safrida ◽  
Yarmaliza Yarmaliza ◽  
Fitrah Reynaldi ◽  
Arfah Husna

The quality of drinking water supply must be guaranteed. The WHO (World Health Organization) determines water quality by means of E. Coli bacteria. Based on the Minister of Health Regulation No. 492 / MENKES / PER / IV / 2010 The maximum permissible content of E. Coli in drinking water is 0 per 100 ml. The presence of E. coli in water is an indicator of human and animal fecal pollution that can cause diarrhea and even death. Selection of Refillable Drinking Water (AMIU) as an alternative to fulfill drinking water needs is a risk that can endanger health if the quality of AMIU is added if consumers do not pay attention to safety and hygiene. This study aims to see the content of E. coli in Refill Drinking Water (AMIU) in Samatiga District, West Aceh Regency. This research is experimental with cross sectional design using quantitative laboratory examination with the Most Probable Number (MPN) method. The population in this study were all refill drinking water depots that did not have a drinking certificate in Samatiga District, West Aceh Regency. The research sample used a total sampling method of 7 refill drinking water depots. The results of the analysis showed that from all samples as many as 6 samples (85.71%) tested positive for Escherichia coli bacteria and 1 sample (14.29%) tested negative for Escherichia coli bacteria. Based on the calculation of the number of colonies with the MPN / 100 ml table then comparing with the requirements of the Regulation of the Minister of Health of the Republic of Indonesia Number 492 / Menkes / Per / IV / 2010 concerning drinking water quality requirements that the 6 samples tested positive were not suitable for consumption.


2006 ◽  
Vol 72 (11) ◽  
pp. 6914-6922 ◽  
Author(s):  
Matthew A. Anderson ◽  
John E. Whitlock ◽  
Valerie J. Harwood

ABSTRACT Escherichia coli is the most completely characterized prokaryotic model organism and one of the dominant indicator organisms for food and water quality testing, yet comparatively little is known about the structure of E. coli populations in their various hosts. The diversities of E. coli populations isolated from the feces of three host species (human, cow, and horse) were compared by two subtyping methods: ribotyping (using HindIII) and antibiotic resistance analysis (ARA). The sampling effort required to obtain a representative sample differed by host species, as E. coli diversity was consistently greatest in horses, followed by cattle, and was lowest in humans. The diversity of antibiotic resistance patterns isolated from individuals was consistently greater than the diversity of ribotypes. E. coli populations in individuals sampled monthly, over a 7- to 8-month period, were highly variable in terms of both ribotypes and ARA phenotypes. In contrast, E. coli populations in cattle and humans were stable over an 8-h period. Following the cessation of antibiotic therapy, the E. coli population in the feces of one human experienced a rapid and substantial shift, from a multiply antibiotic-resistant phenotype associated with a particular ribotype to a relatively antibiotic-susceptible phenotype associated with a different ribotype. The high genetic diversity of E. coli populations, differences in diversity among hosts, and temporal variability all indicate complex population dynamics that influence the usefulness of E. coli as a water quality indicator and its use in microbial source tracking studies.


2011 ◽  
Vol 9 (4) ◽  
pp. 734-737 ◽  
Author(s):  
Richard S. Quilliam ◽  
Katie Clements ◽  
Caroline Duce ◽  
Simon B. Cottrill ◽  
Shelagh K. Malham ◽  
...  

Escherichia coli are often used as faecal indicator bacteria (FIB) to provide a measure of microbial pollution in recreational and shellfish harvesting waters. However, although model forecasts for predicting the concentrations of FIB in surface waters are becoming more robust, they suffer from an inconsistency in quantification methods and an understanding of the spatial variation of FIB within a water course. The aim of this study was to investigate the transverse spatial variation in E. coli numbers (as an indicator of faecal pollution) across the estuary of the River Conwy, UK. Water samples were collected from four transverse transects across the estuary. Spatial variation of E. coli was significantly different from one side of the river to the other, although was not correlated with depth or the physiochemical properties of the water. Subsequently, microbial water quality classifications on the two opposite banks suggested very different levels of pollution coming down the river. This work has shown that the side of the river that routine water monitoring samples are taken from can make a significant difference to the classification of microbial water quality. This has important implications for sampling strategies and the use of microbial source tracking (MST) techniques.


2010 ◽  
Vol 76 (10) ◽  
pp. 3255-3262 ◽  
Author(s):  
Linda K. Dick ◽  
Erin A. Stelzer ◽  
Erin E. Bertke ◽  
Denise L. Fong ◽  
Donald M. Stoeckel

ABSTRACT Fecal indicator bacteria (FIB), commonly used to regulate sanitary water quality, cannot discriminate among sources of contamination. The use of alternative quantitative PCR (qPCR) methods for monitoring fecal contamination or microbial source tracking requires an understanding of relationships with cultivated FIB, as contamination ages under various conditions in the environment. In this study, the decay rates of three Bacteroidales 16S rRNA gene markers (AllBac for general contamination and qHF183 and BacHum for human-associated contamination) were compared with the decay rate of cultivated Escherichia coli in river water microcosms spiked with human wastewater. The following five sets of microcosms were monitored over 11 days: control, artificial sunlight, sediment exposure, reduced temperature, and no autochthonous predation. Decay was characterized by estimation of the time needed to produce a 2-log reduction (t 99). No treatment-associated differences in the decay of the 4 targets were evident except with reduced predation, where E. coli, qHF183, and BacHum markers had lower levels of decay by day 3. However, there were substantial target-associated differences. Decay curves for the AllBac marker indicated a larger persistent population than those of the other targets. Exposure to sunlight, sediment, and reduced predation resulted in more rapid decay of the human-associated markers relative to cultivable E. coli, but there were no differences in t 99 values among the 4 targets under control conditions or at reduced temperatures. Further evaluation of epidemiological relationships will be needed in order to relate the markers directly to health risk. These findings suggest that the tested human-associated markers can complement E. coli as indicators of the human impact on sanitary water quality under the constrained conditions described in this paper.


Author(s):  
Yu.A. Novikova ◽  
I.O. Myasnikov ◽  
A.A. Kovshov ◽  
N.A. Tikhonova ◽  
N.S. Bashketova

Summary. Introduction: Drinking water is one of the most important environmental factors sustaining life and determining human health. The goal of the Russian Federal Clean Water Project is to improve drinking water quality through upgrading of water treatment and supply systems using advanced technologies, including those developed by the military-industrial complex. The most informative and reliable sources of information for assessing drinking water quality are the results of systematic laboratory testing obtained within the framework of socio-hygienic monitoring (SGM) and production control carried out by water supply organizations. The objective of our study was to formulate approaches to organizing quality monitoring programs for centralized cold water supply systems. Materials and methods: We reviewed programs and results of drinking water quality laboratory tests performed by Rospotrebnadzor bodies and institutions within the framework of SGM in 2017–2018. Results: We established that drinking water quality monitoring in the constituent entities of the Russian Federation differs significantly in the number of monitoring points (566 in the Krasnoyarsk Krai vs 10 in Sevastopol) and measured indicators, especially sanitary and chemical ones (53 inorganic and organic substances in the Kemerovo Region vs one indicator in the Amur Region). Discussion: For a more complete and objective assessment of drinking water quality in centralized cold water supply systems, monitoring points should be organized at all stages of water supply with account for the coverage of the maximum number of people supplied with water from a particular network. Thus, the number of points in the distribution network should depend, inter alia, on the size of population served. In urban settlements with up to 10,000 inhabitants, for example, at least 4 points should be organized while in the cities with more than 3,000,000 inhabitants at least 80 points are necessary. We developed minimum mandatory lists of indicators and approaches to selecting priority indices to be monitored at all stages of drinking water supply.


2021 ◽  
Vol 193 (8) ◽  
Author(s):  
Desmond Tichaona Mugadza ◽  
Sibusisiwe Isabel Nduku ◽  
Edlyn Gweme ◽  
Sherpherd Manhokwe ◽  
Patience Marume ◽  
...  

2021 ◽  
Author(s):  
Megan Devane ◽  
Brent Gilpin ◽  
Jennifer Webster-Brown ◽  
Louise Weaver ◽  
Pierre Dupont ◽  
...  

&lt;p&gt;The intensification of dairy farming on the agricultural landscape in New Zealand has raised concerns about pollution sources from dairy faecal runoff into waterways. The transport of faecal pollution from farms into waterways is facilitated by overland flow, which can result from rain and flood events, poorly designed irrigation practices and the washing down of milking sheds.&lt;/p&gt;&lt;p&gt;An important step for mitigation of pollution is the identification of the source(s) of faecal contamination. When elevated levels of faecal indicator bacteria (FIB) such as &lt;em&gt;Escherichia coli &lt;/em&gt;are identified in a waterway, faecal source tracking (FST) tools such as microbial source tracking (MST) using quantitative polymerase chain reaction (qPCR), and faecal steroids (for example, cholesterol) provide information about the sources of faecal contamination. The understanding of the fate (degradation/persistence) and transport of these FST markers in the environment is recognised as an important requirement for the interpretation of water quality monitoring in aquatic environments.&lt;/p&gt;&lt;p&gt;This study investigated the effects of faecal decomposition on bovine faecal indicators (&lt;em&gt;E. coli &lt;/em&gt;and FST markers: bovine-associated qPCR markers and ten faecal steroids) by monitoring the effect of flood and rainfall events on simulated cowpats over a five and a half month period under field conditions. Two separate spring/summer trials were conducted to evaluate: Trial 1) the mobilisation under simulated flood conditions of the faecal indicators from irrigated versus non-irrigated cowpats, Trial 2) the mobilisation of faecal indicators from non-irrigated cowpat flood runoff versus runoff after simulated rainfall onto non-irrigated cowpats.&lt;/p&gt;&lt;p&gt;The microbial community changes within the decomposing cowpat (as illustrated by amplicon-based metagenomic analysis) were expected to impact on the survival/persistence of the bacterial targets of the MST markers, and also alter the ratio between faecal sterols and their biodegradation products, the stanols. It was hypothesised, therefore, that there would be:&lt;/p&gt;&lt;ul&gt;&lt;li&gt;Changes over time in the concentration of&lt;em&gt; E. coli &lt;/em&gt;and the bovine-associated MST markers mobilised into the cowpat runoff&lt;/li&gt; &lt;li&gt;Alterations in the FST ratio signature of the ten measured faecal steroids, resulting in a change from a bovine faecal steroid signature in fresh cowpat runoff to other animal faecal signatures in the runoff from decomposing cowpats&lt;/li&gt; &lt;li&gt;A difference in the mobilisation decline rates of all FST and microbial markers within a treatment regime and between treatments.&lt;/li&gt; &lt;/ul&gt;&lt;p&gt;Linear regression analysis was undertaken to establish mobilisation decline rates for each of the analytes in the mobilisable phase from the cowpat runoff treatments, with calculation of the time taken in days for reduction in 90% of the concentration (T&lt;sub&gt;90&lt;/sub&gt;), and statistical comparison of the regression coefficients (slopes) of all analytes. The results will include a discussion of the impacts of the study&amp;#8217;s observations on the interpretation of faecal indicator assessments for water quality monitoring in waterways influenced by sources of faecal contamination.&lt;/p&gt;


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