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Moses A, Ramírez-Andreotta MD, McLain JET, Obergh V, Rutin E, Sandhaus S, Kilungo AP. The efficacy of hydrogen sulfide (H 2S) tests for detecting microbial contamination in rooftop-harvested rainwater. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:1398. [PMID: 37910273 PMCID: PMC10620290 DOI: 10.1007/s10661-023-11942-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 10/05/2023] [Indexed: 11/03/2023]
Abstract
As climate change strains the world's freshwater resources, access to safe and clean water becomes limited. The use of alternative water sources, such as rooftop-harvested rainwater, has become one mechanism to address freshwater scarcity in the American Southwest, particularly when it comes to home gardening. The University of Arizona's Project Harvest, in partnership with the Sonora Environmental Research Institute, Inc., is a multi-year, co-created citizen science project aimed at increasing current understanding of harvested rainwater quality. Citizens in four Arizona, USA, communities (Hayden/Winkelman, Globe/Miami, Dewey-Humboldt, and Tucson) submitted harvested rainwater samples over 3 years. The harvested rainwater samples were then analyzed using IDEXX Colilert® for total coliforms and E. coli and using Hach PathoScreen™ test for sulfate-reducing bacteria (SRB). This study design allows for the validation of a low-cost, at-home alternative methodology for testing rainwater for bacteria that may indicate fecal contamination. In total, 226 samples were tested using both methodologies, revealing a positive correlation (r=0.245; p<0.002) between total coliform MPN and SRB MPN, but no discernable correlation between E. coli MPN and SRB MPN. This work indicates a potential value of SRB testing for harvested rainwater if cost, laboratory access, and fecal contamination are of concern.
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Affiliation(s)
- Arthur Moses
- Department of Environmental Science, University of Arizona, 1177 E. Fourth St, Tucson, AZ, 85721, USA
| | - Mónica D Ramírez-Andreotta
- Department of Environmental Science, University of Arizona, 1177 E. Fourth St, Tucson, AZ, 85721, USA
- Mel and Enid Zuckerman College of Public Health, Department of Community, Environment and Policy, University of Arizona, 1295 N. Martin Ave, Tucson, AZ, 85721, USA
| | - Jean E T McLain
- Department of Environmental Science, University of Arizona, 1177 E. Fourth St, Tucson, AZ, 85721, USA
- Water Resources Research Center, University of Arizona, 350 N. Campbell Ave, Tucson, AZ, 85719, USA
| | - Victoria Obergh
- Department of Environmental Science, University of Arizona, 1177 E. Fourth St, Tucson, AZ, 85721, USA
| | - Emma Rutin
- Mel and Enid Zuckerman College of Public Health, Department of Community, Environment and Policy, University of Arizona, 1295 N. Martin Ave, Tucson, AZ, 85721, USA
| | - Shana Sandhaus
- Department of Environmental Science, University of Arizona, 1177 E. Fourth St, Tucson, AZ, 85721, USA
| | - Aminata P Kilungo
- Mel and Enid Zuckerman College of Public Health, Department of Community, Environment and Policy, University of Arizona, 1295 N. Martin Ave, Tucson, AZ, 85721, USA.
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Crocker J, Bartram J. Comparison and cost analysis of drinking water quality monitoring requirements versus practice in seven developing countries. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2014; 11:7333-46. [PMID: 25046632 PMCID: PMC4113879 DOI: 10.3390/ijerph110707333] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 06/12/2014] [Accepted: 07/08/2014] [Indexed: 11/16/2022]
Abstract
Drinking water quality monitoring programs aim to support provision of safe drinking water by informing water quality management. Little evidence or guidance exists on best monitoring practices for low resource settings. Lack of financial, human, and technological resources reduce a country's ability to monitor water supply. Monitoring activities were characterized in Cambodia, Colombia, India (three states), Jordan, Peru, South Africa, and Uganda according to water sector responsibilities, monitoring approaches, and marginal cost. The seven study countries were selected to represent a range of low resource settings. The focus was on monitoring of microbiological parameters, such as E. coli, coliforms, and H2S-producing microorganisms. Data collection involved qualitative and quantitative methods. Across seven study countries, few distinct approaches to monitoring were observed, and in all but one country all monitoring relied on fixed laboratories for sample analysis. Compliance with monitoring requirements was highest for operational monitoring of large water supplies in urban areas. Sample transport and labor for sample collection and analysis together constitute approximately 75% of marginal costs, which exclude capital costs. There is potential for substantive optimization of monitoring programs by considering field-based testing and by fundamentally reconsidering monitoring approaches for non-piped supplies. This is the first study to look quantitatively at water quality monitoring practices in multiple developing countries.
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Affiliation(s)
- Jonny Crocker
- The Water Institute, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, 148 Rosenau Hall, CB #7431 Chapel Hill, NC 27599, USA.
| | - Jamie Bartram
- The Water Institute, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, 148 Rosenau Hall, CB #7431 Chapel Hill, NC 27599, USA.
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Bain R, Cronk R, Wright J, Yang H, Slaymaker T, Bartram J. Fecal contamination of drinking-water in low- and middle-income countries: a systematic review and meta-analysis. PLoS Med 2014; 11:e1001644. [PMID: 24800926 PMCID: PMC4011876 DOI: 10.1371/journal.pmed.1001644] [Citation(s) in RCA: 269] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Accepted: 04/03/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Access to safe drinking-water is a fundamental requirement for good health and is also a human right. Global access to safe drinking-water is monitored by WHO and UNICEF using as an indicator "use of an improved source," which does not account for water quality measurements. Our objectives were to determine whether water from "improved" sources is less likely to contain fecal contamination than "unimproved" sources and to assess the extent to which contamination varies by source type and setting. METHODS AND FINDINGS Studies in Chinese, English, French, Portuguese, and Spanish were identified from online databases, including PubMed and Web of Science, and grey literature. Studies in low- and middle-income countries published between 1990 and August 2013 that assessed drinking-water for the presence of Escherichia coli or thermotolerant coliforms (TTC) were included provided they associated results with a particular source type. In total 319 studies were included, reporting on 96,737 water samples. The odds of contamination within a given study were considerably lower for "improved" sources than "unimproved" sources (odds ratio [OR] = 0.15 [0.10-0.21], I2 = 80.3% [72.9-85.6]). However over a quarter of samples from improved sources contained fecal contamination in 38% of 191 studies. Water sources in low-income countries (OR = 2.37 [1.52-3.71]; p<0.001) and rural areas (OR = 2.37 [1.47-3.81] p<0.001) were more likely to be contaminated. Studies rarely reported stored water quality or sanitary risks and few achieved robust random selection. Safety may be overestimated due to infrequent water sampling and deterioration in quality prior to consumption. CONCLUSION Access to an "improved source" provides a measure of sanitary protection but does not ensure water is free of fecal contamination nor is it consistent between source types or settings. International estimates therefore greatly overstate use of safe drinking-water and do not fully reflect disparities in access. An enhanced monitoring strategy would combine indicators of sanitary protection with measures of water quality.
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Affiliation(s)
- Robert Bain
- The Water Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Ryan Cronk
- The Water Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Jim Wright
- University of Southampton, Southampton, United Kingdom
| | - Hong Yang
- University of Southampton, Southampton, United Kingdom
| | | | - Jamie Bartram
- The Water Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
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Luyt CD, Tandlich R, Muller WJ, Wilhelmi BS. Microbial monitoring of surface water in South Africa: an overview. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2012; 9:2669-93. [PMID: 23066390 PMCID: PMC3447580 DOI: 10.3390/ijerph9082669] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 07/06/2012] [Accepted: 07/12/2012] [Indexed: 11/16/2022]
Abstract
Infrastructural problems force South African households to supplement their drinking water consumption from water resources of inadequate microbial quality. Microbial water quality monitoring is currently based on the Colilert®18 system which leads to rapidly available results. Using Escherichia coli as the indicator microorganism limits the influence of environmental sources on the reported results. The current system allows for understanding of long-term trends of microbial surface water quality and the related public health risks. However, rates of false positive for the Colilert®18-derived concentrations have been reported to range from 7.4% to 36.4%. At the same time, rates of false negative results vary from 3.5% to 12.5%; and the Colilert medium has been reported to provide for cultivation of only 56.8% of relevant strains. Identification of unknown sources of faecal contamination is not currently feasible. Based on literature review, calibration of the antibiotic-resistance spectra of Escherichia coli or the bifidobacterial tracking ratio should be investigated locally for potential implementation into the existing monitoring system. The current system could be too costly to implement in certain areas of South Africa where the modified H(2)S strip test might be used as a surrogate for the Colilert®18.
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Affiliation(s)
- Catherine D. Luyt
- Environmental Health and Biotechnology Research Group, Division of Pharmaceutical Chemistry, Faculty of Pharmacy, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa;
| | - Roman Tandlich
- Environmental Health and Biotechnology Research Group, Division of Pharmaceutical Chemistry, Faculty of Pharmacy, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa;
| | - Wilhelmine J. Muller
- Unilever Centre for Environmental Water Quality, Institute for Water Research, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa;
| | - Brendan S. Wilhelmi
- Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, P.O. Box 94, Grahamstown 6140, South Africa;
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McMahan L, Grunden AM, Devine AA, Sobsey MD. Evaluation of a quantitative H2S MPN test for fecal microbes analysis of water using biochemical and molecular identification. WATER RESEARCH 2012; 46:1693-1704. [PMID: 22244995 DOI: 10.1016/j.watres.2011.12.037] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Revised: 12/15/2011] [Accepted: 12/16/2011] [Indexed: 05/31/2023]
Abstract
The sensitivity and specificity of the H(2)S test to detect fecal bacteria in water has been variable and uncertain in previous studies, partly due to its presence-absence results. Furthermore, in groundwater samples false-positive results have been reported, with H(2)S-positive samples containing no fecal coliforms or Escherichia coli. False-negative results also have been reported in other studies, with H(2)S-negative samples found to contain E. coli. Using biochemical and molecular methods and a novel quantitative test format, this research identified the types and numbers of microbial community members present in natural water samples, including fecal indicators and pathogens as well as other bacteria. Representative water sources tested in this study included cistern rainwater, a protected lake, and wells in agricultural and forest settings. Samples from quantitative H(2)S tests of water were further cultured for fecal bacteria by spread plating onto the selective media for detection and isolation of Aeromonas spp., E. coli, Clostridium spp., H(2)S-producers, and species of Salmonella and Shigella. Isolates were then tested for H(2)S production, and identified to the genus and species level using biochemical methods. Terminal Restriction Fragment Length Polymorphisms (TRFLP) was the molecular method employed to quantitatively characterize microbial community diversity. Overall, it was shown that water samples testing positive for H(2)S bacteria also had bacteria of likely fecal origin and waters containing fecal pathogens also were positive for H(2)S bacteria. Of the microorganisms isolated from natural water, greater than 70 percent were identified using TRFLP analysis to reveal a relatively stable group of organisms whose community composition differed with water source and over time. These results further document the validity of the H(2)S test for detecting and quantifying fecal contamination of water.
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Affiliation(s)
- Lanakila McMahan
- University of North Carolina at Chapel Hill, Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, Chapel Hill, NC 27599, USA.
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Pathak SP, Gopal K. Efficiency of modified H2S test for detection of faecal contamination in water. ENVIRONMENTAL MONITORING AND ASSESSMENT 2005; 108:59-65. [PMID: 16160778 DOI: 10.1007/s10661-005-3960-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2003] [Accepted: 09/21/2004] [Indexed: 05/04/2023]
Abstract
Faecal contamination is a major causative factor for incidence of water borne infectious diseases. Certain hydrogen sulfide (H(2)S) producing enteric bacteria such as Salmonella sp. and Citrobacter sp., associated with coliforms, have been considered for rapid detection of recent faecal contamination in water. The basic H(2)S test medium, modified by adding 0.25 gm/L of L-cystine HCl, was examined for its efficiency with 90 water samples collected from 40 pipe supplies, 20 open wells, 15 hand pumps and 15 different surface water bodies (river, streams and ponds). Sterilized modified culture medium in glass vials was inoculated with 100 mL of each sample and incubated at 20, 25, 30, 35 and 44 degrees C for 18, 24, 42, 48, 66 and 72 h. Blackening of content in incubated vials was considered positive. For comparison, most probable number (MPN) of coliform and faecal coliform per 100 mL was also estimated in each sample by multiple tube fermentation (MTF) method. H(2)S positive result was exhibited by 78% of samples. Coliform (> 10) and faecal coliform/100 mL were also detected in 59% of samples. Maximum H(2)S positive results (100%) were found with well and surface water samples incubated at 30, 35 and 44 degrees C for 18 h. Coliform (> 10) and faecal coliform/100 mL were also detected in most of these samples. Pipe supplies (60%) and hand pumps (73%) also exhibited considerable H(2)S production. Coliforms and faecal coliforms were also found in significant number of these samples. Thus, the modified H(2)S test may prove a useful alternative indicator of faecal contamination for water quality surveillance and screening of large number of water samples in short duration, particularly during any outbreak of water borne disease among rural population.
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Affiliation(s)
- S P Pathak
- Aquatic Toxicology Division, Industrial Toxicology Research Centre, M. G. Marg, Lucknow, India.
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Pillai SD, Widmer KW, Dowd SE, Ricke SC. Occurrence of airborne bacteria and pathogen indicators during land application of sewage sludge. Appl Environ Microbiol 1996; 62:296-9. [PMID: 8572708 PMCID: PMC167798 DOI: 10.1128/aem.62.1.296-299.1996] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Glass impingers (AGI-30) were used at a commercial sludge application site to determine the levels of airborne bacteria and pathogen indicators. Even though heterotrophic bacteria averaged 10(5) CFU/m3, none of the sites showed the presence of Salmonella spp. or indicators such as fecal coliforms or coliphages. Indicators such as H2S producers and pathogenic clostridia were present in locations having significant physical agitation of the sludge material. PCR-based ribotyping using the 16S-23S interspacer region is a promising method to identify the genetic relatedness and origins of airborne clostridia.
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Affiliation(s)
- S D Pillai
- Environmental Science Program, Texas A&M University Research Center, El Paso, USA
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Hernandez J, Kaspar C, Hartman P, Colwell R. Microtitration plate most-probable-number tests for the enumeration of Escherichia coli in estuarine and marine waters. J Microbiol Methods 1993. [DOI: 10.1016/0167-7012(93)90067-r] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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