Seasonal influence of environmental variables and artificial aeration on Escherichia coli in small urban lakes

This study investigated patterns of Escherichia coli in urban lakes in Lubbock, Texas. Specific objectives were to (1) document seasonal patterns in abundance of E. coli over a 3-year period, (2) identify environmental factors, including effects of migratory geese and artificial aeration devices that may influence E. coli abundance, and (3) determine if E. coli abundance over time was similar for individual lakes. Water samples were collected monthly for 36 months from six lakes, three of which contained artificial aeration devices (fountains). Regression models were constructed to determine which environmental variables most influence E. coli abundance in summer and winter seasons. Escherichia coli is present in the lakes of Lubbock, Texas year-round and typically exceeds established bacterial thresholds for recreational waters. Models most frequently contained pH and dissolved oxygen as predictor variables and explained from 17.4% to 92.4% of total variation in E. coli. Lakes with fountains had a higher oxygen concentration during summer and contained consistently less E. coli. We conclude that solar irradiation in synergy with pH and dissolved oxygen is the primary control mechanism for E. coli in study lakes, and that fountains help control abundance of fecal bacteria within these systems.

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Colistin-Resistant mcr-1-Positive Escherichia coli on Public Beaches, an Infectious Threat Emerging in Recreational Waters

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00234-17 ◽

2017 ◽

Vol 61 (7) ◽

Cited By ~ 46

Author(s):

Miriam R. Fernandes ◽

Fábio P. Sellera ◽

Fernanda Esposito ◽

Caetano P. Sabino ◽

Louise Cerdeira ◽

...

Keyword(s):

Escherichia Coli ◽

Recreational Waters ◽

Content Type ◽

E Coli ◽

Rapid Spread ◽

Environmental Reservoir ◽

Public Beaches ◽

Urban Beaches

ABSTRACT The emergence and rapid spread of colistin-resistant Escherichia coli carrying the mcr-1 gene have generated an urgent need to strengthen surveillance. We performed a meticulous investigation of strains of this sort, which resulted in the identification of international clones of E. coli carrying IncX4-plasmid-mediated mcr-1 and bla CTX-M genes in recreational waters of public urban beaches in cities with high tourist turnover, highlighting a new environmental reservoir.

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A Virulence and Antimicrobial Resistance DNA Microarray Detects a High Frequency of Virulence Genes in Escherichia coli Isolates from Great Lakes Recreational Waters

Applied and Environmental Microbiology ◽

10.1128/aem.00137-06 ◽

2006 ◽

Vol 72 (6) ◽

pp. 4200-4206 ◽

Cited By ~ 82

Author(s):

Katia Hamelin ◽

Guillaume Bruant ◽

Abdel El-Shaarawi ◽

Stephen Hill ◽

Thomas A. Edge ◽

...

Keyword(s):

Public Health ◽

Escherichia Coli ◽

Antimicrobial Resistance ◽

Great Lakes ◽

Dna Microarray ◽

Resistance Genes ◽

Virulence Genes ◽

Recreational Waters ◽

E Coli ◽

Antimicrobial Resistance Genes

ABSTRACT Escherichia coli is generally described as a commensal species with occasional pathogenic strains. Due to technological limitations, there is currently little information concerning the prevalence of pathogenic E. coli strains in the environment. For the first time, using a DNA microarray capable of detecting all currently described virulence genes and commonly found antimicrobial resistance genes, a survey of environmental E. coli isolates from recreational waters was carried out. A high proportion (29%) of 308 isolates from a beach site in the Great Lakes carried a pathotype set of virulence-related genes, and 14% carried antimicrobial resistance genes, findings consistent with a potential risk for public health. The results also showed that another 8% of the isolates had unusual virulence gene combinations that would be missed by conventional screening. This new application of a DNA microarray to environmental waters will likely have an important impact on public health, epidemiology, and microbial ecology in the future.

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Impact of Metazooplankton Filter Feeding on Escherichia coli under Variable Environmental Conditions

Applied and Environmental Microbiology ◽

10.1128/aem.02006-19 ◽

2019 ◽

Vol 85 (23) ◽

Cited By ~ 1

Author(s):

Niveen S. Ismail ◽

Brittney M. Blokker ◽

Tyler R. Feeney ◽

Ruby H. Kohn ◽

Jingyi Liu ◽

...

Keyword(s):

Escherichia Coli ◽

Water Quality ◽

Surface Waters ◽

Environmental Variables ◽

Bacterial Species ◽

Clearance Rates ◽

Filter Feeding ◽

Fecal Indicator ◽

Content Type ◽

E Coli

ABSTRACT The fecal indicator bacterial species Escherichia coli is an important measure of water quality and a leading cause of impaired surface waters. We investigated the impact of the filter-feeding metazooplankton Daphnia magna on the inactivation of E. coli. The E. coli clearance rates of these daphnids were calculated from a series of batch experiments conducted under variable environmental conditions. Batch system experiments of 24 to 48 h in duration were completed to test the impacts of bacterial concentration, organism density, temperature, and water type. The maximum clearance rate for adult D. magna organisms was 2 ml h−1 organism−1. Less than 5% of E. coli removed from water by daphnids was recoverable from excretions. Sorption of E. coli on daphnid carapaces was not observed. As a comparison, the clearance rates of the freshwater rotifer Branchionus calyciflorus were also calculated for select conditions. The maximum clearance rate for B. calyciflorus was 6 × 10−4 ml h−1 organism−1. This research furthers our understanding of the impacts of metazooplankton predation on E. coli inactivation and the effects of environmental variables on filter feeding. Based on our results, metazooplankton can play an important role in the reduction of E. coli in natural treatment systems under environmentally relevant conditions. IMPORTANCE Escherichia coli is a fecal indicator bacterial species monitored by the U.S. Environmental Protection Agency to assess microbial water quality. Due to the potential human health implications linked to high levels of E. coli, it is important to understand the inactivation or reduction mechanisms in surface waters. Our research examines the capacities of two types of widespread filter-feeding freshwater metazooplankton, Daphnia magna and Brachionus calyciflorus, to reduce E. coli concentrations. We examine the impacts of different environmentally relevant conditions on the clearance rates. Our results contribute to a better understanding of the importance of metazooplankton in controlling E. coli concentrations and what conditions will reduce or increase grazing. These results provide baseline data to support future efforts to develop a quantitative model relating zooplankton uptake rates to relevant environmental variables.

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Relationship between eae and stx Virulence Genes and Escherichia coli in an Agricultural Watershed: Implications for Irrigation Water Standards and Leafy Green Commodities†

Journal of Food Protection ◽

10.4315/0362-028x.jfp-10-241 ◽

2011 ◽

Vol 74 (1) ◽

pp. 18-23 ◽

Cited By ~ 18

Author(s):

DANIEL R. SHELTON ◽

JEFFREY S. KARNS ◽

CARY COPPOCK ◽

JITU PATEL ◽

MANAN SHARMA ◽

...

Keyword(s):

Escherichia Coli ◽

Virulence Genes ◽

Agricultural Watershed ◽

Recreational Waters ◽

Waterborne Pathogen ◽

E Coli ◽

Leafy Greens ◽

Genes Encoding ◽

Forested Areas ◽

Irrigation Waters

The California Leafy Greens Marketing Agreement (LGMA) was adopted in an effort to minimize the risk of contamination of leafy greens with enteric pathogens from a variety of sources, including ground and surface irrigation waters. The LGMA contains standards similar to those established for recreational waters, based on Escherichia coli concentrations. However, no correlation between E. coli and any specific waterborne pathogen(s) has been reported. We conducted this monitoring study in an agricultural watershed to (i) evaluate spatial and temporal fluctuations in E. coli populations and virulence genes associated with pathogenic E. coli and (ii) investigate whether a relationship could be established between E. coli and virulence genes. The virulence genes targeted for analysis were the eae and stx genes, encoding for intimin and Shiga-like toxins, respectively; they were detected with PCR methods. E. coli concentrations and eae and stx prevalence varied both spatially and temporally. In general, both were higher in agricultural than in forested areas and were higher in the summer and fall seasons than in winter. The eae and stx genes were prevalent throughout the watershed. However, in the absence of actual isolates, no conclusions could be drawn regarding the prevalence of specific pathogenic E. coli. No correlation was observed between E. coli concentrations and virulence genes; lower E. coli concentrations were not necessarily associated with decreased prevalence of eae and stx genes. These results suggest that the LGMA standards might not adequately address the issue of waterborne contamination, and that alternative criteria might be required.

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Optimized Dissolved Oxygen Fuzzy Control for Recombinant Escherichia coli Cultivations

Algorithms ◽

10.3390/a14110326 ◽

2021 ◽

Vol 14 (11) ◽

pp. 326

Author(s):

Rafael Akira Akisue ◽

Matheus Lopes Harth ◽

Antonio Carlos Luperni Horta ◽

Ruy de Sousa Junior

Keyword(s):

Escherichia Coli ◽

Decision Tree ◽

Dissolved Oxygen ◽

Fuzzy Inference ◽

Recombinant Escherichia Coli ◽

Oxygen Flow ◽

Oxygen Solubility ◽

Inference System ◽

Flow Rates ◽

E Coli

Due to low oxygen solubility and mechanical stirring limitations of a bioreactor, ensuring an adequate oxygen supply during a recombinant Escherichia coli cultivation is a major challenge in process control. Under the light of this fact, a fuzzy dissolved oxygen controller was developed, taking into account a decision tree algorithm presented in the literature, and implemented in the supervision software SUPERSYS_HCDC. The algorithm was coded in MATLAB with its membership function parameters determined using an Adaptive Network-Based Fuzzy Inference System tool. The controller was composed of three independent fuzzy inference systems: Princ1 and Princ2 assessed whether there would be an increment or a reduction in air and oxygen flow rates (respectively), whilst Delta estimated the size of these variations. To test the controller, simulations with a neural network model and E. coli cultivations were conducted. The fuzzification of the decision tree was successful, resulting in smoothing of air and oxygen flow rates and, hence, in an attenuation of dissolved oxygen oscillations. Statistically, the average standard deviation of the fuzzy controller was 2.45 times lower than the decision tree (9.48%). Results point toward an increase in the flow meter lifespan and a possible reduction of the metabolic stress suffered by E. coli during the cultivation.

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Repetitive element (REP)-polymerase chain reaction (PCR) analysis of Escherichia coli isolates from recreational waters of southeastern Lake Huron

Canadian Journal of Microbiology ◽

10.1139/w08-123 ◽

2009 ◽

Vol 55 (3) ◽

pp. 269-276 ◽

Cited By ~ 23

Author(s):

Tanya Kon ◽

Susan C. Weir ◽

E. Todd Howell ◽

Hung Lee ◽

Jack T. Trevors

Keyword(s):

Escherichia Coli ◽

Repetitive Element ◽

Microbial Source Tracking ◽

Lake Huron ◽

Source Tracking ◽

Chain Reaction ◽

Recreational Waters ◽

E Coli ◽

Potential Sources ◽

Polymerase Chain

Repetitive element-polymerase chain reaction (REP-PCR) DNA fingerprinting and library-based microbial source tracking (MST) methods were utilized to investigate the potential sources of Escherichia coli pollution in recreational waters of southeastern Lake Huron. In addition to traditional sources such as humans, agriculture, and wildlife, environmentally persistent E. coli isolates were included in the identification library as a separate library unit consisting of the E. coli strains isolated from interstitial water on the beach itself. Our results demonstrated that the dominant source of E. coli pollution of the lake was agriculture, followed by environmentally adapted E. coli strains, wildlife, and then humans. A similar ratio of contributing sources was observed in all samples collected from various locations including the river discharging to the beach in both 2005 and 2006. The high similarity between the compositions of E. coli communities collected simultaneously in the river and in the lake suggests that tributaries were the major overall sources of E. coli to the lake. Our findings also suggest that environmentally adapted strains (EAS) of E. coli should be included as one of the potential sources in future microbial source tracking efforts.

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Comparison of Rapid Quantitative PCR-Based and Conventional Culture-Based Methods for Enumeration of Enterococcus spp. and Escherichia coli in Recreational Waters

Applied and Environmental Microbiology ◽

10.1128/aem.00651-10 ◽

2010 ◽

Vol 76 (22) ◽

pp. 7437-7443 ◽

Cited By ~ 94

Author(s):

Rachel T. Noble ◽

A. Denene Blackwood ◽

John F. Griffith ◽

Charles D. McGee ◽

Stephen B. Weisberg

Keyword(s):

Escherichia Coli ◽

Water Quality ◽

Quantitative Pcr ◽

23S Rrna ◽

Management Decision ◽

Beach Management ◽

Recreational Waters ◽

E Coli ◽

Conventional Culture ◽

Pure Cultures

ABSTRACT Recreational water quality is currently monitored using culture-based methods that require 18 to 96 h for results. Quantitative PCR (QPCR) methods that can be completed in less than 2 h have been developed, but they could yield different results than the conventional methods. We present two studies in which samples were processed simultaneously for Enterococcus spp. and Escherichia coli using two culture-based methods (EPA method 1600 and Enterolert/Colilert-18) and QPCR. The proprietary QPCR assays targeted the 23S rRNA (Enterococcus spp.) and uidA (E. coli) genes and were conducted using lyophilized beads containing all reagents. In the first study, the QPCR method developers processed 54 blind samples that were inoculated with sewage or pure cultures or were ambient beach samples. The second study involved 163 samples processed by water quality personnel. The correlation between results of QPCR and EPA 1600 during the first study (r 2) was 0.69 for Enterococcus spp., which was less than that observed between the culture-based methods (r 2, 0.87). During the second study, the correlations were similar. No false positives occurred in either study when QPCR-based assays were used with blank samples. Levels of reproducibility measured through coefficients of variation were similar for results by Enterococcus QPCR and culture-based methods during both studies but were higher for E. coli QPCR results in the first study. Regarding the concentration at which beach management decisions are issued in the State of California, the agreement between results of Enterococcus QPCR and EPA method 1600 was 88%, compared to 94% agreement between EPA method 1600 and Enterolert. The beach management decision agreement between E. coli QPCR and Colilert-18 was 94%. The samples showing disagreement suggested an underestimation bias for QPCR.

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Genetic Relatedness of Escherichia coli Isolates in Interstitial Water from a Lake Huron (Canada) Beach

Applied and Environmental Microbiology ◽

10.1128/aem.02437-06 ◽

2007 ◽

Vol 73 (6) ◽

pp. 1961-1967 ◽

Cited By ~ 23

Author(s):

Tatiana Kon ◽

Susan C. Weir ◽

E. Todd Howell ◽

Hung Lee ◽

Jack T. Trevors

Keyword(s):

Escherichia Coli ◽

Water Samples ◽

Genetic Relatedness ◽

Interstitial Water ◽

Lake Huron ◽

Beach Sand ◽

Sampling Location ◽

Swash Zone ◽

Recreational Waters ◽

E Coli

ABSTRACT Research was undertaken to characterize Escherichia coli isolates in interstitial water samples of a sandy beach on the southeastern shore of Lake Huron, Ontario, Canada. A survey of the beach area revealed the highest abundance of E. coli in interstitial water of the foreshore beach sand next to the swash zone. Higher concentrations of E. coli (up to 1.6 × 106 CFU/100 ml of water) were observed in the interstitial water from the sampling holes on the beach itself compared to lake water and sediment. Repetitive extragenic palindromic PCR (REP-PCR) was used to characterize the genetic diversity of E. coli isolates from interstitial water samples on the beach. E. coli isolates from the same sampling location frequently exhibited the same REP-PCR pattern or were highly similar to each other. In contrast, E. coli isolates from different sampling locations represented populations distinct from each other. This study has identified a unique ecological niche within the foreshore area of the beach where E. coli may survive and possibly multiply outside of host organisms. The results are of interest as increasing concentrations of E. coli in recreational waters are often considered to be an indication of recent fecal pollution.

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Relationships between abiotic and biotic variables in a maturation pond and their influence on E. coli removal

Water Science & Technology ◽

10.2166/wst.2021.268 ◽

2021 ◽

Author(s):

Ana M. M. Batista ◽

Daniella do Valle ◽

Daniel F. C. Dias ◽

Luciene A. B. Sinischachi ◽

Bruna Coelho Lopes ◽

...

Keyword(s):

Escherichia Coli ◽

Ultraviolet Radiation ◽

Dissolved Oxygen ◽

Driving Forces ◽

Zooplankton Community ◽

Domestic Wastewater ◽

E Coli ◽

Bacterial Removal ◽

Significant Difference ◽

Integral Role

Abstract The effects of depth and climate seasonality on zooplankton, algal biomass, coliforms and Escherichia coli in a small full-scale shallow maturation pond receiving pre-treated domestic wastewater were evaluated during a tropical climatic seasonal cycle. The experiment revealed that the zooplankton community was dominated by rotifers and protozoans, and concentrations were influenced by seasonality. A negative correlation between zooplankton, and pH, Dissolved Oxygen, temperature and ultraviolet radiation, and Chlorophyll-a and Escherichia coli were observed at all depths. The major driving forces influencing Escherichia coli were pH, Dissolved Oxygen, ultraviolet radiation and the zooplankton. A significant difference between Escherichia coli removal throughout the three different depths were observed. Both bacterial and zooplankton concentrations were greater closer to the bottom of the pond, therefore reinforcing the integral role of solar radiation on bacterial removal. These results give an insight on the dynamics of these groups in pond systems treating domestic wastewater, by correlating the variation of zooplankton with biotic and abiotic variables and seasonal changes in a tropical climate, where few studies have been performed on this topic.

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Effects of pH, Dissolved Oxygen, and Ionic Strength on the Survival of Escherichia coli O157:H7 in Organic Acid Solutions†‡

Journal of Food Protection ◽

10.4315/0362-028x-71.12.2404 ◽

2008 ◽

Vol 71 (12) ◽

pp. 2404-2409 ◽

Cited By ~ 14

Author(s):

AUDREY C. KRESKE ◽

KRISTIN BJORNSDOTTIR ◽

FRED BREIDT ◽

HOSNI HASSAN

Keyword(s):

Escherichia Coli ◽

Ionic Strength ◽

Dissolved Oxygen ◽

Tap Water ◽

Escherichia Coli O157 ◽

Acid Solutions ◽

E Coli ◽

Vegetable Products ◽

The Individual ◽

Acidified Foods

The ability of Escherichia coli O157:H7 to survive in acidified vegetable products is of concern because of previously documented outbreaks associated with fruit juices. A study was conducted to determine the survival of E. coli O157:H7 in organic acids at pH values typical of acidified vegetable products (pH 3.2 and 3.7) under different dissolved oxygen conditions (≤0.05 and 5 mg/liter) and a range of ionic strengths (0.086 to 1.14). All solutions contained 20 mM gluconic acid, which was used as a noninhibitory low pH buffer to compare the individual acid effect to that of pH alone on the survival of E. coli O157:H7. E. coli O157:H7 cells challenged in buffered solution with ca. 5-mg/liter dissolved oxygen (present in tap water) over a range of ionic strengths at pH 3.2 exhibited a decrease in survival over 6 h at 30°C as the ionic strength was increased. Cells challenged in 40 mM protonated l-lactic and acetic acid solutions with ionic strength of 0.684 achieved a >4.7-log CFU/ml reduction at pH 3.2. However, under oxygen-limiting conditions in an anaerobic chamber, with ≤0.05-mg/liter oxygen, E. coli O157:H7 cells showed ≤1.55-log CFU/ml reduction regardless of pH, acid type, concentration, or ionic strength. Many acid and acidified foods are sold in hermetically sealed containers with oxygen-limiting conditions. Our results demonstrate that E. coli O157:H7 may survive better than previously expected from studies with acid solutions containing dissolved oxygen.

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