Comparison of methods and confirmation tests for the recovery Escherichia coli in water

Bonadonna, Lucia; Cataldo, Claudia; Semproni, Maurizio

doi:10.1016/j.desal.2006.03.601

Cited by 12 publications

(5 citation statements)

References 15 publications

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“…coli by definition. The organisms isolated from false positive wells in South Africa are summarized in S3 Table and in all cases at least one of the predominant isolates has been reported to have β -glucuronidase activity: Citrobacter freundii [ 37 ] and Enterobacter cloacae [ 38 ], Klebsiella oxytoca [ 39 ] and Enterobacter sakazakii [ 40 ]. In isolating predominant strains, it is possible that the bacteria responsible for false positives were not identified.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of an Inexpensive Growth Medium for Direct Detection of Escherichia coli in Temperate and Sub-Tropical Waters

et al. 2015

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The cost and complexity of traditional methods for the detection of faecal indicator bacteria, including E. coli, hinder widespread monitoring of drinking water quality, especially in low-income countries and outside controlled laboratory settings. In these settings the problem is exacerbated by the lack of inexpensive media for the detection of E. coli in drinking water. We developed a new low-cost growth medium, aquatest (AT), and validated its use for the direct detection of E. coli in temperate and sub-tropical drinking waters using IDEXX Quanti-Tray®. AT was compared with IDEXX Colilert-18® and either EC-MUG or MLSB for detecting low levels of E. coli from water samples from temperate (n = 140; Bristol, UK) and subtropical regions (n = 50, Pretoria/Tshwane, South Africa). Confirmatory testing (n = 418 and 588, respectively) and the comparison of quantitative results were used to assess performance. Sensitivity of AT was higher than Colilert-18® for water samples in the UK [98.0% vs. 86.9%; p<0.0001] and South Africa [99.5% vs. 93.2%; p = 0.0030]. There was no significant difference in specificity, which was high for both media (>95% in both settings). Quantitative results were comparable and within expected limits. AT is reliable and accurate for the detection of E. coli in temperate and subtropical drinking water. The composition of the new medium is reported herein and can be used freely.

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Section: Discussionmentioning

confidence: 99%

Evaluation of an Inexpensive Growth Medium for Direct Detection of Escherichia coli in Temperate and Sub-Tropical Waters

et al. 2015

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“…The Colilert system simultaneously detects and enumerates total coliforms and E. coli, and does not require any confirmation steps (Edberg et al 1988). In addition, the Colilert 18 method demonstrated the highest accuracy in the detection of E. coli in comparison to other standard methods used (Edberg et al 1988;Buckalew et al 2006;Bonadonna et al 2007). This method was originally developed for the examination of water samples, but it has been also employed for testing wastewater, sludge, sediment, soil, and various other environmental samples (Muirhead et al 2004;Lee et al 2006;Ottoson et al 2006).…”

Section: Methodsmentioning

confidence: 96%

Long-term survival of Escherichia coli in lightweight aggregate filter media of constructed wastewater treatment wetlands

Paruch

2011

Water Science and Technology

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A laboratory scale experiment on the survival of Escherichia coli in samples of filter media from a horizontal subsurface flow constructed wetland treating domestic wastewater was performed. A concentration of E. coli was examined in samples collected from a wetland filter filled with lightweight aggregates (LWA). All samples testing positive for E. coli contamination were used to examine the effect of storage time on the survival of E. coli at three temperature regimes: cold (4°C), mild (10°C) and warm (22°C). It was found that the mild storage condition favoured the growth and survival of E. coli in the tested LWA media. The growth in samples of the uppermost layer of the media lasted for 5.5 months, during which E. coli reached a maximum concentration of 6.4×10(3) MPN/100 g dry matter in the media. It was also observed that E. coli had a greater capacity to survive for extended periods of time in samples collected from the upper layer of the LWA filter compared to samples taken from the deeper layers. The survival of E. coli in the shallowest samples of the wetland filter was remarkably long and unexpected, lasting for a period of over 14 months.

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“…The media were chosen for their ability to differentiate E. coli colonies, allow detection at low and high concentrations, inhibit non-target microorganisms and enhance injured (Niemelä et al 2003;Bonadonna et al 2007) and officially accepted by many countries (testing requirements as per ISO 17994, paragraph 5.3.8).…”

Section: Microbiological Methodsmentioning

confidence: 99%

“…Hamilton et al (2006) and Bonadonna et al (2007) report that Chromocult Coliform agar is more sensitive than the ISO reference procedure.…”

Section: Chromocult Coliform Agar Vs Ttc Tergitol 7 Agarmentioning

confidence: 97%

Equivalency testing of TTC Tergitol 7 agar (ISO 9308-1:2000) with five culture media for the detection of E. coli in water samples in Greece

Mavridou

Smeti

Mandilara

et al. 2010

Water Science and Technology

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In this study ten laboratories in Greece compared the performance of reference method TTC Tergitol 7 Agar (with the additional test of beta-glucuronidase production) with five alternative methods, to detect E. coli in water, in line with European Water Directive recommendations. The samples were prepared by spiking drinking water with sewage effluent following a standard protocol. Chlorinated and non-chlorinated samples were used. The statistical analysis was based on the mean relative difference of confirmed counts and was performed in line with ISO 17994. The results showed that in total, three of the alternative methods (Chromocult Coliform agar, Membrane Lauryl Sulfate agar and Trypton Bilex-glucuronidase medium) were not different from TTC Tergitol 7 agar (TTC Tergitol 7 agar vs Chromocult Coliform agar, 294 samples, mean RD% 5.55; vs MLSA, 302 samples, mean RD% 1; vs TBX, 297 samples, mean RD% -2.78). The other two alternative methods (Membrane Faecal coliform medium and Colilert 18/ Quantitray) gave significantly higher counts than TTC Tergitol 7 agar (TTC Tergitol 7 agar vs MFc, 303 samples, mean RD% 8.81; vs Colilert-18/Quantitray, 76 samples, mean RD% 18.91). In other words, the alternative methods generated performance that was as reliable as, or even better than, the reference method. This study will help laboratories in Greece overcome culture and counting problems deriving from the EU reference method for E. coli counts in water samples.

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Comparison of methods and confirmation tests for the recovery Escherichia coli in water

Cited by 12 publications

References 15 publications

Evaluation of an Inexpensive Growth Medium for Direct Detection of Escherichia coli in Temperate and Sub-Tropical Waters

Evaluation of an Inexpensive Growth Medium for Direct Detection of Escherichia coli in Temperate and Sub-Tropical Waters

Long-term survival of Escherichia coli in lightweight aggregate filter media of constructed wastewater treatment wetlands

Equivalency testing of TTC Tergitol 7 agar (ISO 9308-1:2000) with five culture media for the detection of E. coli in water samples in Greece

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