Concentrations of Escherichia Coli in Streams in the Upper Wabash River Watershed in Indiana, June-September 1998

2000 ◽  
Keyword(s):  
Escherichia Coli ◽  
River Watershed ◽  
Wabash River

Hydrologic alterations in the Wabash River watershed, USA

2008 ◽  
Vol 24 (8) ◽  
pp. 1175-1184 ◽  
Author(s):  
Mark Pyron ◽  
Klaus Neumann
Keyword(s):  
River Watershed ◽  
Wabash River ◽  
Hydrologic Alterations

Factors affecting the occurrence of Escherichia coli O157 contamination in irrigation ponds on produce farms in the Suwannee River Watershed

2013 ◽  
Vol 59 (3) ◽  
pp. 175-182 ◽  
Author(s):  
Ganyu Gu ◽  
Zhiyao Luo ◽  
Juan M. Cevallos-Cevallos ◽  
Paige Adams ◽  
George Vellidis ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Environmental Factors ◽  
Water Samples ◽  
Fecal Coliforms ◽  
Subsurface Water ◽  
Escherichia Coli O157 ◽  
Culturable Bacteria ◽  
River Watershed ◽  
E Coli ◽  
Suwannee River

Outbreaks of enteritis caused by Escherichia coli O157 associated with fresh produce have resulted in questions about the safety of irrigation water; however, associated risks have not been systematically evaluated. In this study, the occurrence and distribution of the human pathogen E. coli O157 from vegetable irrigation ponds within the Suwannee River Watershed in Georgia were investigated, and the relationship to environmental factors was analyzed. Surface and subsurface water samples were collected monthly from 10 vegetable irrigation ponds from March 2011 to February 2012. Escherichia coli O157 was isolated from enriched filtrates on CHROMagar and sorbitol MacConkey agar media and confirmed by an agglutination test. Presence of virulence genes stx1, stx2 , and eae was tested by polymerase chain reaction. In addition, 27 environmental variables of the sampled ponds were measured. Denaturing gradient gel electrophoresis was conducted for the analysis of bacterial communities in the water samples. Biserial correlation coefficients were calculated to evaluate the log10 colony-forming unit per millilitre correlations between the environmental factors and the occurrence of E. coli O157. Stepwise and canonical discriminant analyses were used to determine the factors that were associated with the presence and absence of E. coli O157 in water samples. All 10 ponds were positive for E. coli O157 some of the time, mainly in summer and fall of 2011. The temporal distribution of this bacterium differed among the 10 ponds. Temperature, rainfall, populations of fecal coliform, and culturable bacteria were positively correlated with the occurrence of E. coli O157 (P < 0.05), while the total nitrogen concentration, oxidation–reduction potential, and dissolved oxygen concentration were negatively correlated with the occurrence of this pathogen (P < 0.05). Temperature and rainfall were the most important factors contributing to the discrimination between samples with and without E. coli O157, followed by bacterial diversity and culturable bacteria population density. Bacterial numbers and diversity, including fecal coliforms and E. coli O157, increased after rainfall (and possibly runoff from pond margins) in periods with relatively high temperatures, suggesting that prevention of runoff may be important to minimize the risk of enteric pathogens in irrigation ponds.

scholarly journals First detection of diarrheagenic Escherichia coli pathotypes in the Mearim River Watershed, Maranhão State, Brazil

2021 ◽  
Vol 42 (6supl2) ◽  
pp. 3869-3882
Author(s):  
Vitórya Mendes da Silva Monteiro ◽  
◽  
Edianez dos Santos Mendes ◽  
Kelyane da Costa Silva Menezes ◽  
Carlos Alberto Guimarães ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Water Resource ◽  
Fruits And Vegetables ◽  
Enzymatic System ◽  
Supply Source ◽  
River Watershed ◽  
E Coli ◽  
Diarrheagenic Escherichia Coli ◽  
Pure Cultures ◽  
Typical Epec

The Mearim River Watershed has multiple uses e.g. leisure, navigation, fishing and subsistence agriculture and constitutes the main source of supply for the populations of municipalities situated along its course. In addition to being a water supply source, the existence of the ‘pororoca’ (tidal bore) effect in a stretch of the lower course of the Mearim River attracts people from several Brazilian states and different countries, as it offers excellent conditions for surfing in fresh water. In this respect, given the importance of the watershed, this study was developed to report the detection of diarrheagenic Escherichia coli pathotypes in a stretch of the lower course of the Mearim River, located in the state of Maranhão, Brazil. Thirty water samples were collected from 10 sampling points. To quantify E. coli, the chromogenic enzymatic system was used and positive samples were isolated and biochemically identified. Pure cultures underwent DNA extraction by heating followed by polymerase chain reaction (PCR) characterization. At the time of the collections, an observation schedule was used to record information on the existence of rearing of livestock and domestic animals; businesses; residences; and fruit and vegetable farming on the riverbanks. The samples were analyzed for the mean populations of E. coli, which ranged from 444 to 2,585 MPN mL-1. Twenty bacterial isolates were identified and the diarrheal pathotypes ETEC, typical EPEC and atypical EPEC were detected. The detection of these pathotypes can represent an epidemiological risk and compromise several uses of this water resource, such as irrigation of fruits and vegetables consumed raw, fishing, animal watering and recreation. Structural investments in basic sanitation are essential to minimize environmental degradation resulting from anthropic activities and to act preventively in public health. In addition, the recovery of riparian forests along the watershed and the maintenance of vegetation in these areas are measures to reduce the transport of particles from the soil to the watercourses, improving the qualitative and quantitative characteristics of this water resource.

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