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

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 lowincome 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 QuantiTray1. AT was compared with IDEXX Colilert-181 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-181 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

A Summary Catalogue of Microbial Drinking Water Tests for Low and Medium Resource Settings

Microbial drinking-water quality testing plays an essential role in measures to protect public health. However, such testing remains a significant challenge where resources are limited. With a wide variety of tests available, researchers and practitioners have expressed difficulties in selecting the most appropriate test(s) for a particular budget, application and setting. To assist the selection process we identified the characteristics associated with low and medium resource settings and we specified the basic information that is needed for different forms of water quality monitoring. We then searched for available faecal indicator bacteria tests and collated this information. In total 44 tests have been identified, 18 of which yield a presence/absence result and 26 of which provide enumeration of bacterial concentration. The suitability of each test is assessed for use in the three settings. The cost per test was found to vary from $0.60 to$5.00 for a presence/absence test and from $0.50 to$7.50 for a quantitative format, though it is likely to be only a small component of the overall costs of testing. This article presents the first comprehensive catalogue of the characteristics of available and emerging low-cost tests for faecal indicator bacteria. It will be of value to organizations responsible for monitoring national water quality, water service providers, researchers and policy makers in selecting water quality tests appropriate for a given setting and application

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

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%; p95% 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

Training future generations to deliver evidence-based conservation and ecosystem management

1. To be effective, the next generation of conservation practitioners and managers need to be critical thinkers with a deep understanding of how to make evidence-based decisions and of the value of evidence synthesis. 2. If, as educators, we do not make these priorities a core part of what we teach, we are failing to prepare our students to make an effective contribution to conservation practice. 3. To help overcome this problem we have created open access online teaching materials in multiple languages that are stored in Applied Ecology Resources. So far, 117 educators from 23 countries have acknowledged the importance of this and are already teaching or about to teach skills in appraising or using evidence in conservation decision-making. This includes 145 undergraduate, postgraduate or professional development courses. 4. We call for wider teaching of the tools and skills that facilitate evidence-based conservation and also suggest that providing online teaching materials in multiple languages could be beneficial for improving global understanding of other subject areas.Peer reviewe

Accounting for water quality in monitoring access to safe drinking-water as part of the Millennium Development Goals: lessons from five countries

Objective: To take account of source water quality in estimating access to safe drinking water under Millennium Development Goal (MDG) target 7c and adjust reported progress.Methods: For five countries, we adjust the Joint Monitoring Programme (JMP) methods for reporting baseline and progress towards MDG Target 7c by incorporating the results from nationally representative surveys of the microbial and chemical quality of improved water sources. We cross-checked our application of these methods with JMP.Findings: Accounting for microbial and chemical compliance with a subset of WHO water quality guidelines as part of the MDG indicator substantially reduces reported access to ‘safe’ water in 2008 for four of the five countries: Ethiopia (11%), Nicaragua (16%), Nigeria (15%), and Tajikistan (7%). In these countries, the mix of improved sources includes substantial numbers of unsafe sources that have poor water quality. Adjusting for microbial compliance has the larger effect.Conclusion: Although our analysis cannot be extrapolated to global scale, it suggests that the current MDG indicator overestimates levels of access to safe water and that in some countries the over-estimation is substantial. In future monitoring developments, separately capturing the effects of access and water quality would represent a significant improvement

Improved but not necessarily safe: water access and the Millennium Development Goals

This article examines the consequences of the disparity between the drinking-water target of the Millennium Development Goals and the measure used to report progress. It has recently been announced that the target had been met in 2010. The authors adjust reported figures to reflect that the official measure, use of an ‘improved water source’, may not always indicate safe water. They find that progress towards the target may have been substantially over-estimate

Water safety and inequality in access to drinking-water between rich and poor households

While water and sanitation are now recognized as a human right by the United Nations, monitoring inequality in safe water access poses challenges. This study uses survey data to calculate household socio-economic-status (SES) indices in seven countries where national drinking-water quality surveys are available. These are used to assess inequalities in access as indicated by type of improved water source, use of safe water and a combination of these . In Bangladesh, arsenic exposure through drinking-water is not significantly related to SES (p=0.06) among households using tubewells, whereas in Peru, chlorine residual in piped systems varies significantly with SES (p&lt;0.0001). In Ethiopia, Nicaragua and Nigeria, many poor households access non-piped improved sources, which may provide unsafe water, resulting in greater inequality of access to ‘safe’ water compared to ‘improved’ water sources. Concentration indices increased from 0.08 to 0.15, 0.10 to 0.14, and 0.24 to 0.26 respectively in these countries. There was minimal difference in Jordan and Tajikistan. Although the results are likely to be underestimates as they exclude individual-level inequalities, they show that use of a binary ‘improved’ / ‘unimproved’ categorization masks substantial inequalities. Future international monitoring programmes should take account inequality in access and safet