scholarly journals Effects of hydrological regime and land use on in-stream Escherichia coli concentration in the Mekong basin, Lao PDR

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paty Nakhle ◽  
Olivier Ribolzi ◽  
Laurie Boithias ◽  
Sayaphet Rattanavong ◽  
Yves Auda ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Land Use ◽  
Surface Water ◽  
Stream Water ◽  
Fecal Contamination ◽  
Lao Pdr ◽  
Fecal Matter ◽  
E Coli ◽  
Sampling Campaign ◽  
Tropical Conditions

AbstractIn the basin of Mekong, over 70 million people rely on unimproved surface water for their domestic requirements. Surface water is often contaminated with fecal matter and yet little information exists on the underlying mechanisms of fecal contamination in tropical conditions at large watershed scales. Our objectives were to (1) investigate the seasonality of fecal contamination using Escherichia coli as fecal indicator bacteria (FIB), and (2) establish links between the fecal contamination in stream water and its controlling factors (hydrology and land use). We present the results of (1) a sampling campaign at the outlet of 19 catchments across Lao PDR, in both the dry and the rainy seasons of 2016, and (2) a 10-day interval monitoring conducted in 2017 and 2018 at three point locations of three rivers (Nam Ou, Nam Suang, and Mekong) in northern Lao PDR. Our results show the presence of fecal contamination at most of the sampled sites, with a seasonality characterized by higher and extreme E. coli concentrations occurring during the rainy season. The highest E. coli concentrations, strongly correlated with total suspended sediment concentrations, were measured in catchments dominated by unstocked forest areas, especially in mountainous northern Lao PDR and in Vientiane province.

scholarly journals Escherichia coli (E. coli) as an Indicator of Fecal Contamination in Water: A Review

2019 ◽  
Author(s):  
Farhan Mohammad Khan ◽  
Rajiv Gupta
Keyword(s):  
Escherichia Coli ◽  
Water Quality ◽  
Drinking Water ◽  
Fecal Coliform ◽  
Fecal Contamination ◽  
Waterborne Diseases ◽  
Fecal Matter ◽  
E Coli ◽  
Detection Techniques ◽  
Pollution Indicator

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 – 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.```

Effects of seasonal hydrology and land use on in-stream Escherichia coli concentration in the lower Mekong basin, Laos

2020 ◽  
Author(s):  
Paty Nakhle ◽  
Olivier Ribolzi ◽  
Laurie Boithias ◽  
Sayaphet Rattanavong ◽  
Yves Auda ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Water Quality ◽  
Land Use ◽  
Suspended Sediment ◽  
Fecal Contamination ◽  
Field Monitoring ◽  
Partial Least Square ◽  
Water Levels ◽  
Mekong River ◽  
E Coli

<p>Despite being a basic human right, limited access to clean water is still a major concern in developing countries lacking adequate sanitary infrastructure. A significant proportion of the global population directly depends on surface water resources which are often contaminated with fecal matter. The presence of fecal contamination in waterbodies is often detected using fecal indicator bacteria like <em>Escherichia coli</em>. According to 2016 UNEP report, about one third to one half of Asian rivers are estimated to be severely polluted, with monthly in-stream concentrations of fecal coliform bacteria exceeding 1000 cfu.100 mL<sup>-1</sup>. Although various studies on small tropical catchments have improved our understanding of <em>E. coli</em> behavior in a tropical context, little information exists on the underlying mechanisms at large watershed scales during dry and wet seasons. Our study focuses on Mekong River and its main tributaries in Laos, an area that has witnessed rapid changes in land use and deterioration of water quality over the last three decades. We aim (1) to examine the seasonality of <em>E. coli</em> concentrations in stream waters, and (2) to identify the main factors controlling<em> E. coli</em> in-stream concentration, such as land use, hydrometeorology, and suspended sediment concentrations, through field monitoring of a range of catchments across Laos. To this end, we used two different sets of field data monitoring at multiple temporal and spatial scales. First, a total of 18 catchment outlets located between 15°N and 20°N, were sampled twice in 2016, during both dry and rainy seasons, covering a broad range of catchment sizes (240 - 25946 km²), as well as geographical and topographical features. Second, three northern rivers, Nam Ou, Nam Suang, and Mekong River, have been sampled every 10 days since July 2017. Our results shed the light on contamination over the year in all three catchments (100-100000 MPN.100 mL<sup>-1</sup>), with higher <em>E. coli</em> concentrations during the rainy season, associated with higher water levels, and higher concentrations of total suspended sediment (TSS) in streams. Partial Least Square (PLS) regression showed a strong positive correlation between <em>E. coli</em> concentrations and the percentage of unstocked forests area. Unstocked forests are exposed to erosion processes resulting in high concentrations of suspended sediment and particle-attached <em>E. coli</em> in-stream concentrations. In contrast, catchments with larger protected and naturally regenerated forest and grassland areas were associated with lower <em>E. coli</em> and TSS concentrations. These analyses highlight the importance of adequate land management in tropical context to reduce soil loss and water quality degradation. Furthermore, our results reveal the importance of improving our understanding of fate and transport of fecal contamination through field monitoring at various spatial and temporal scales, in order to assess the risk to public health, and the impact on ecosystem services, such as contaminant retention.</p>

scholarly journals Genetic diversity of Escherichia coli isolates from surface water and groundwater in a rural environment

2017 ◽  
Vol 15 (5) ◽  
pp. 757-765 ◽  
Author(s):  
Maria Laura Gambero ◽  
Monica Blarasin ◽  
Susana Bettera ◽  
Jesica Giuliano Albo
Keyword(s):  
Escherichia Coli ◽  
Genetic Diversity ◽  
Surface Water ◽  
Water Contamination ◽  
Fecal Contamination ◽  
Genotypic Diversity ◽  
Human Consumption ◽  
Genetic Characteristics ◽  
E Coli ◽  
Surface Water And Groundwater

The genetic characteristics among Escherichia coli strains can be grouped by origin of isolation. Then, it is possible to use the genotypes as a tool to determine the source of water contamination. The aim of this study was to define water aptitude for human consumption in a rural basin and to assess the diversity of E. coli water populations. Thus, it was possible to identify the main sources of fecal contamination and to explore linkages with the hydrogeological environment and land uses. The bacteriological analysis showed that more than 50% of samples were unfit for human consumption. DNA fingerprinting analysis by BOX-PCR indicated low genotypic diversity of E. coli isolates taken from surface water and groundwater. The results suggested the presence of a dominant source of fecal contamination. The relationship between low genotypic diversity and land use would prove that water contamination comes from livestock. The genetic diversity of E. coli isolated from surface water was less than that identified in groundwater because of the different hydraulic features of both environments. Furthermore, each one of the two big strain groups identified in this basin is located in different sub-basins, showing that hydrological dynamics exerts selective pressure on bacteria DNA.

scholarly journals Using GFP-Tagged Escherichia coli to Investigate the Persistence of Fecal Bacteria in Vegetated Wetlands: An Experimental Approach

Antibiotics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 335
Author(s):  
Emilia Chiapponi ◽  
Charles P. Henriot ◽  
Xavier Bertrand ◽  
Didier Hocquet ◽  
Gudrun Bornette
Keyword(s):  
Escherichia Coli ◽  
Surface Water ◽  
Water Column ◽  
Pathogenic Bacteria ◽  
Fluorescent Protein ◽  
Fecal Contamination ◽  
Public Health Issue ◽  
Fecal Bacteria ◽  
Bacterial Survival ◽  
E Coli

The contamination of surface water by pathogenic bacteria of human origin is an important public health issue. Wetlands can be contaminated with fecal bacteria by water originating from different sources, such as wastewater treatment plants and agriculture. Escherichia coli is a commensal of the human gut flora and the major indication of fecal contamination in surface water. Little is known about the association between fecal bacteria and submerged macrophytes and how this may influence the water quality. We questioned whether macrophytes enhance or inhibit the bacterial growth in wetlands. For this purpose, we grew four different species of macrophytes (Mentha aquatica, Baldellia ranunculoides, Sparganium emersum and Elodea canadensis, in mono- or multispecies cultures) in aquatic rhizotrons and inoculated the devices with a fluorescent strain of Escherichia coli (producing a green fluorescent protein) to simulate the fecal contamination of wetlands. Bacterial survival was monitored by measuring the fluorescence for 19 days. We found (i) that contaminated sediments did not release E. coli in the water column in lentic conditions and (ii) that monocultures of E. canadensis, M. aquatica and S. emersum reduced the E. coli concentration in the water column. This suggests that aquatic plant species may be used in constructed wetlands to clear surface freshwater from bacteria of fecal origin.

scholarly journals Escherichia coli is not a suitable fecal indicator to assess water fecal contamination by otters

2017 ◽  
Vol 78 (1) ◽  
pp. 155-159 ◽  
Author(s):  
M. Oliveira ◽  
D. Freire ◽  
N. M. Pedroso
Keyword(s):  
Escherichia Coli ◽  
Fecal Contamination ◽  
Microbiological Quality ◽  
Aquatic Environments ◽  
Pathogenic Microorganisms ◽  
Fecal Indicator ◽  
Fecal Samples ◽  
E Coli ◽  
Paulo State

Abstract The detection of pathogenic microorganisms in aquatic environments is extremely relevant in terms of public health. As these laboratorial methodologies are usually difficult, expensive and time-consuming, they are frequently replaced by the assessment of fecal indicator bacteria, such as Escherichia coli. This study aimed to assess the presence of E. coli in fecal samples from Neotropical otters, to evaluate its potential as fecal indicator to be applied to the determination of water microbiological quality in areas where otters’ populations are high. Twenty-six otter fecal samples, collected in Alto Paranapanema river basin, São Paulo State, Brazil, were analyzed for the presence of E. coli, using conventional bacteriological methods. Only 8 scat samples (30%) were E. coli positive, indicating that this microorganism is not a suitable fecal indicator to assess water fecal contamination by Neotropical otters, and should not be used to infer the presence of otter related pathogens in waters.

scholarly journals Numerical investigation of the spatial distribution of Escherichia coli in river deltas for different values of river discharge, temperature and irradiation of the water surface

2020 ◽  
Vol 3 (1) ◽  
pp. 69-76
Author(s):  
Nicoletta Leonardi ◽  
Constantinos Matsoukis ◽  
Iacopo Carnacina
Keyword(s):  
Escherichia Coli ◽  
Spatial Distribution ◽  
River Discharge ◽  
Water Surface ◽  
Shelf Area ◽  
Quality Model ◽  
Fecal Matter ◽  
E Coli ◽  
River Deltas ◽  
Discharge Temperature

Abstract Escherichia coli and other enteric pathogens presence indicate that the water has been contaminated with fecal matter. River deltas are population hotspots which are becoming increasingly urbanized and where poor sanitation has been frequently identified as a pressing issue. In this study, we have investigated the spatial distribution of E. coli in river deltas under varying river discharge, temperature and irradiation at the water surface. A hydrodynamic and water quality model has been used to reproduce an idealized river delta configuration and to investigate the spatial distribution of E. coli across the delta floodplain and channels. The concentration of E. coli rapidly declines downstream, following a tripartite trend with different decline rates on the delta front, pro-delta and shelf area. The highest differences in the spatial distribution of E. coli bacteria occur for low-river discharge values. Temperature and irradiation both influence the concentration of E. coli and mostly influence downstream areas and smaller channels.

scholarly journals Genome Sequence of a T4-like Phage, Escherichia Phage vB_EcoM-Sa45lw, Infecting Shiga Toxin-Producing Escherichia coli Strains

2019 ◽  
Vol 8 (32) ◽  
Author(s):  
Yen-Te Liao ◽  
Yujie Zhang ◽  
Alexandra Salvador ◽  
Vivian C. H. Wu
Keyword(s):  
Escherichia Coli ◽  
Surface Water ◽  
Genome Size ◽  
Shiga Toxin ◽  
Open Reading Frames ◽  
Content Type ◽  
E Coli ◽  
Double Stranded Dna ◽  
A Genome ◽  
Reading Frames

Escherichia phage vB_EcoM-Sa45lw, a new member of the T4-like phages, was isolated from surface water in a produce-growing area. The phage, containing double-stranded DNA with a genome size of 167,353 bp and 282 predicted open reading frames (ORFs), is able to infect generic Escherichia coli and Shiga toxin-producing E. coli O45 and O157 strains.

Effect of Prechill Fecal Contamination on Numbers of Bacteria Recovered from Broiler Chicken Carcasses Before and After Immersion Chilling

2004 ◽  
Vol 67 (9) ◽  
pp. 1829-1833 ◽  
Author(s):  
J. A. CASON ◽  
M. E. BERRANG ◽  
R. J. BUHR ◽  
N. A. COX
Keyword(s):  
Escherichia Coli ◽  
Broiler Chickens ◽  
Broiler Chicken ◽  
Tap Water ◽  
Fecal Contamination ◽  
Bacterial Counts ◽  
E Coli ◽  
Before And After ◽  
Marked Area ◽  
Skin Samples

Paired carcass halves were used to test whether fecal contamination of skin during processing of broiler chickens can be detected by increased bacterial counts in samples taken before and after immersion chilling. In each of three trials, six freshly defeathered and eviscerated carcasses were cut in half, and a rectangle (3 by 5 cm) was marked with dots of ink on the breast skin of each half. One half of each pair was chosen randomly, and 0.1 g of freshly collected feces was spread over the rectangle with a spatula. After 10 min, both halves were sprayed with tap water for 10 to 15 s until feces could no longer be seen in the marked area. Both halves were sampled with a 1-min carcass rinse and were then put in a paddle chiller with other eviscerated carcasses for 45 min to simulate industrial immersion chilling. Immediately after chilling, each carcass half was subjected to another 1-min rinse, after which the skin within the rectangle was aseptically removed from the carcass halves and stomached. Rinses of fecally contaminated halves had significantly higher Enterobacteriaceae immediately before chilling, but there were no differences in coliform and Escherichia coli counts. After chilling, there were no differences in Enterobacteriaceae, coliform, and E. coli counts in rinse or skin samples from the paired carcass halves. Correlations were generally poor between counts in rinse and skin samples but were significant between prechill and postchill rinses for both control and fecally contaminated halves. Correlations were also significant between counts in rinses of control and contaminated halves of the same carcass after chilling. Bacterial counts in postchill carcass rinses did not indicate that fecal contamination occurred before chilling.

Survival of Escherichia coli in agricultural soil and presence in tile drainage and shallow groundwater

2010 ◽  
Vol 90 (3) ◽  
pp. 495-505 ◽  
Author(s):  
A C VanderZaag ◽  
K J Campbell ◽  
R C Jamieson ◽  
A C Sinclair ◽  
L G Hynes
Keyword(s):  
Escherichia Coli ◽  
Fecal Contamination ◽  
Shallow Groundwater ◽  
Drainage Water ◽  
Tile Drainage ◽  
Subsurface Water ◽  
Bacterial Survival ◽  
Manure Application ◽  
Monitoring Wells ◽  
E Coli

Animal agriculture and the use of manure as a soil amendment can lead to enteric pathogens entering water used for drinking, irrigation, and recreation. The presence of Escherichia coli in water is commonly used as an indicator of recent fecal contamination; however, a few recent studies suggest some E. coli populations are able to survive for extended time periods in agricultural soils. This important finding needs to be further assessed with field-scale studies. To this end, we conducted a 1-yr study within a 9.6-ha field that had received fertilizer and semi-solid dairy cattle manure annually for the past decade. Escherichia coli concentrations were monitored throughout the year (before and after manure application) in the effluent from tile drains (at approximately 80 cm depth) and in 5- to 8-m-deep groundwater wells. Escherichia coli was detected in both groundwater and tile drain effluent at concentrations exceeding irrigation and recreational water-quality guidelines. Within two of the monitoring wells, concentrations of E. coli, and frequency of detections, were greatest several months after the manure application. In two monitoring wells and one tile drain the frequency of E. coli detections was higher before manure was applied than after. This suggests the presence and abundance of E. coli was not strongly related to the timing of manure application. A laboratory study using naladixic acid resistant E. coli showed the bacteria could survive at least two times longer in soil samples collected from the study field than in soil from the adjacent riparian area, which had not received manure applications. Together, field and lab results suggest that a consistent source of E. coli exists within the field, which may include “naturalized” strains of E. coli. Further studies are required to determine the specific source of E. coli detected in tile drainage water and shallow groundwater. If the E. coli recovered in subsurface water is primarily mobilized from naturalized populations residing within the soil profile, this indicator organism would have little value as an indicator of recent fecal contamination. Key words: Bacterial survival, naturalized Escherichia coli, groundwater, tile drainage

scholarly journals Plant-Pathogenic Oomycetes, Escherichia coli Strains, and Salmonella spp. Frequently Found in Surface Water Used for Irrigation of Fruit and Vegetable Crops in New York State

2014 ◽  
Vol 80 (16) ◽  
pp. 4814-4820 ◽  
Author(s):  
Lisa A. Jones ◽  
Randy W. Worobo ◽  
Christine D. Smart
Keyword(s):  
Escherichia Coli ◽  
Water Quality ◽  
New York ◽  
Food Safety ◽  
Surface Water ◽  
New York State ◽  
Quality Parameters ◽  
Content Type ◽  
York State ◽  
E Coli

ABSTRACTIn the United States, surface water is commonly used to irrigate a variety of produce crops and can harbor pathogens responsible for food-borne illnesses and plant diseases. Understanding when pathogens infest water sources is valuable information for produce growers to improve the food safety and production of these crops. In this study, prevalence data along with regression tree analyses were used to correlate water quality parameters (pH, temperature, turbidity), irrigation site properties (source, the presence of livestock or fowl nearby), and precipitation data to the presence and concentrations ofEscherichia coli,Salmonellaspp., and hymexazol-insensitive (HIS) oomycetes (PhytophthoraandPythiumspp.) in New York State surface waters. A total of 123 samples from 18 sites across New York State were tested forE. coliandSalmonellaspp., of which 33% and 43% were positive, respectively. Additionally, 210 samples from 38 sites were tested for HIS oomycetes, and 88% were found to be positive, with 10 species ofPhytophthoraand 11 species ofPythiumbeing identified from the samples. Regression analysis found no strong correlations between water quality parameters, site factors, or precipitation to the presence or concentration ofE. coliin irrigation sources. ForSalmonella, precipitation (≤0.64 cm) 3 days before sampling was correlated to both presence and the highest counts. Analyses for oomycetes found creeks to have higher average counts than ponds, and higher turbidity levels were associated with higher oomycete counts. Overall, information gathered from this study can be used to better understand the food safety and plant pathogen risks of using surface water for irrigation.

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