<i>E. coli</i> as a public health indicator of drinking water quality

Standridge, Jon H.

doi:10.1002/j.1551-8833.2008.tb08143.x

Cited by 22 publications

(11 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…coli is recognized as an indicator of fecal pollution by the United States, Australia, the European Union, and the World Health Organization (53). Recent studies challenge its utility as an indicator with the identification of "naturalized" E. coli strains that persist and grow autochthonously under natural environmental conditions (5,24,25).…”

Section: Downloaded Frommentioning

confidence: 99%

Cryptic Lineages of the Genus Escherichia

Walk

Alm

Gordon

et al. 2009

Appl Environ Microbiol

244

View full text Add to dashboard Cite

Extended multilocus sequence typing (MLST) analysis of atypical Escherichia isolates was used to identify five novel phylogenetic clades (CI to CV) among isolates from environmental, human, and animal sources. Analysis of individual housekeeping loci showed that E. coli and its sister clade, CI, remain largely indistinguishable and represent nascent evolutionary lineages. Conversely, clades of similar age (CIII and CIV) were found to be phylogenetically distinct. When all Escherichia lineages (named and unnamed) were evaluated, we found evidence that Escherichia fergusonii has evolved at an accelerated rate compared to E. coli, CI, CIII, CIV, and CV, suggesting that this species is younger than estimated by the molecular clock method. Although the five novel clades were phylogenetically distinct, we were unable to identify a discriminating biochemical marker for all but one of them (CIII) with traditional phenotypic profiling. CIII had a statistically different phenotype from E. coli that resulted from the loss of sucrose and sorbitol fermentation and lysine utilization. The lack of phenotypic distinction has likely hindered the ability to differentiate these clades from typical E. coli, and so their ecological significance and importance for applied and clinical microbiology are yet to be determined. However, our sampling suggests that CIII, CIV, and CV represent environmentally adapted Escherichia lineages that may be more abundant outside the host gastrointestinal tract.

show abstract

Section: Downloaded Frommentioning

confidence: 99%

Cryptic Lineages of the Genus Escherichia

Walk

Alm

Gordon

et al. 2009

Appl Environ Microbiol

244

View full text Add to dashboard Cite

show abstract

“…Escherichia coli are commonly used in testing recreational water for the presence of fecal contamination (USEPA, ; Tallon et al ., ; Ishii & Sadowsky, ; Standridge, ). To be considered a reliable fecal indicator, an organism should be unable to replicate in the environment and have similar persistence to fecal pathogens (Ishii & Sadowsky, ).…”

Section: Introductionmentioning

confidence: 99%

Persistence of Escherichia coli in freshwater periphyton: biofilm-forming capacity as a selective advantage

Moreira

Brown

et al. 2011

FEMS Microbiol Ecol

View full text Add to dashboard Cite

Recent research has shown that Escherichia coli can persist in aquatic environments, although the characteristics that contribute to their survival remain poorly understood. This study examines periphytic E. coli populations that were continuously present in three temperate freshwater lakes from June to October 2008 in numbers ranging from 2 to 2 × 10(2) CFU 100 cm(-2) . A crystal violet assay revealed that all tested periphytic E. coli isolates were superior biofilm formers and they formed, on average, 2.5 times as much biofilm as E. coli isolated from humans, 4.5 times as much biofilm as shiga-like toxin-producing E. coli, and 7.5 times as much biofilm as bovine E. coli isolates. Repetitive extragenic palindromic polymerase chain reaction (REP-PCR) DNA fingerprinting analysis demonstrated the genetically diverse nature of the periphytic isolates, with genetic similarity between strains ranging from 40% to 86%. Additionally, the role of curli fibers in biofilm formation was investigated by comparing biofilm formation with curli expression under optimal conditions, although little correlation (R(2) = 0.095, P = 0.005) was found. The high mean biofilm-forming capacity observed in E. coli isolated from the periphyton suggests that selective pressures may favor E. coli capable of forming biofilms in freshwater environments.

show abstract

“…Escherichia coli alongside other coliform group members are the most widely used water safety microbial indicators [1,2]. Despite some of its limitations as an indicator of microbial water quality [3] and of health risk [4], testing for bacteriological water quality is still considered by major water-and public health-related agencies and organizations as a key element to determine the safety of drinking water, verify the correct operation of water treatment systems, and risk assessment/management strategies.…”

Section: Introductionmentioning

confidence: 99%

A Simple Off-Grid Incubator for Microbiological Water Quality Analysis

Bernardes¹,

Bernardes

Zimmer

et al. 2020

Water

View full text Add to dashboard Cite

There is a need for accessible and low-cost microbiological water quality testing in contexts where diarrheal illness is a major public health concern. In most cases, the quantification of Escherichia coli and other microbial indicators by conventional culture methods requires an incubation step for processed samples at specific temperatures for bacterial growth over a prescribed time. However, incubators can be the most expensive equipment required for such microbial analyses, limiting the number and scope of water quality testing available in low-resource contexts. In this study, a low-cost incubator was developed using a locally available expanded polystyrene (EPS) foam cooler, with two water bottles filled with hot water to heat incubator to a target of 35 °C. The EPS incubator performance was validated by processing 150 water samples in duplicates using the Colilert Quanti-tray/2000 system, incubated in either the EPS incubator or a standard laboratory incubator set at 35 °C. Statistically significant correlations of results indicated that the quantification of E. coli was comparable between both methods. Risk categorizations from standard and EPS incubation results agreed for 141 of 150 (94%) samples, with zero false negatives. In addition to being reasonably mobile the EPS incubator would reduce the cost of such water quality testing, thus potentially increasing the scope of water quality testing coverage.

show abstract

E. coli as a public health indicator of drinking water quality

Cited by 22 publications

References 21 publications

Cryptic Lineages of the Genus Escherichia

Cryptic Lineages of the Genus Escherichia

Persistence of Escherichia coli in freshwater periphyton: biofilm-forming capacity as a selective advantage

A Simple Off-Grid Incubator for Microbiological Water Quality Analysis

Contact Info

Product

Resources

About