Assessment of microbiological quality of drinking water from household tanks in Bermuda

2008 ◽  
Vol 54 (6) ◽  
pp. 495-500 ◽  
Author(s):  
B. Lévesque ◽  
D. Pereg ◽  
E. Watkinson ◽  
J.S. Maguire ◽  
L. Bissonnette ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Membrane Filtration ◽  
Microbiological Quality ◽  
General Information ◽  
Total Coliforms ◽  
E Coli ◽  
Electoral Register ◽  
Highly Correlated

Bermuda residents collect rainwater from rooftops to fulfil their freshwater needs. The objective of this study was to assess the microbiological quality of drinking water in household tanks throughout Bermuda. The tanks surveyed were selected randomly from the electoral register. Governmental officers visited the selected household (n = 102) to collect water samples and administer a short questionnaire about the tank characteristics, the residents’ habits in terms of water use, and general information on the water collecting system and its maintenance. At the same time, water samples were collected for analysis and total coliforms and Escherichia coli were determined by 2 methods (membrane filtration and culture on chromogenic media, Colilert kit). Results from the 2 methods were highly correlated and showed that approximately 90% of the samples analysed were contaminated with total coliforms in concentrations exceeding 10 CFU/100 mL, and approximately 66% of samples showed contamination with E. coli. Tank cleaning in the year prior to sampling seems to protect against water contamination. If rainwater collection from roofs is the most efficient mean for providing freshwater to Bermudians, it must not be considered a source of high quality drinking water because of the high levels of microbial contamination.

scholarly journals Are the defined substrate-based methods adequate to determine the microbiological quality of natural recreational waters?

2009 ◽  
Vol 8 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Marta Sofia Valente ◽  
Paulo Pedro ◽  
M. Carmen Alonso ◽  
Juan J. Borrego ◽  
Lídia Dionísio
Keyword(s):  
Standard Method ◽  
Membrane Filtration ◽  
Microbiological Quality ◽  
Recreational Waters ◽  
Total Coliforms ◽  
E Coli ◽  
Quality Of Water ◽  
Routine Monitoring ◽  
Rapid Tests

Monitoring the microbiological quality of water used for recreational activities is very important to human public health. Although the sanitary quality of recreational marine waters could be evaluated by standard methods, they are time-consuming and need confirmation. For these reasons, faster and more sensitive methods, such as the defined substrate-based technology, have been developed. In the present work, we have compared the standard method of membrane filtration using Tergitol-TTC agar for total coliforms and Escherichia coli, and Slanetz and Bartley agar for enterococci, and the IDEXX defined substrate technology for these faecal pollution indicators to determine the microbiological quality of natural recreational waters. ISO 17994:2004 standard was used to compare these methods. The IDEXX for total coliforms and E. coli, Colilert®, showed higher values than those obtained by the standard method. Enterolert® test, for the enumeration of enterococci, showed lower values when compared with the standard method. It may be concluded that more studies to evaluate the precision and accuracy of the rapid tests are required in order to apply them for routine monitoring of marine and freshwater recreational bathing areas. The main advantages of these methods are that they are more specific, feasible and simpler than the standard methodology.

scholarly journals Multiparametric comparison of chromogenic-based culture methods used to assess the microbiological quality of drinking water and the mFC method combined with a molecular confirmation procedure

2014 ◽  
Vol 13 (1) ◽  
pp. 67-72
Author(s):  
Andrée F. Maheux ◽  
Vanessa Dion-Dupont ◽  
Marc-Antoine Bisson ◽  
Sébastien Bouchard ◽  
Éric Jubinville ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Membrane Filtration ◽  
Microbiological Quality ◽  
Ease Of Use ◽  
Contamination Rate ◽  
Well Water ◽  
Culture Methods ◽  
E Coli ◽  
Agar Method

MI agar and Colilert®, as well as mFC agar combined with an Escherichia coli-specific molecular assay (mFC + E. coli rtPCR), were compared in terms of their sensitivity, ease of use, time to result and affordability. The three methods yielded a positive E. coli signal for 11.5, 10.8, and 11.5% of the 968 well water samples tested, respectively. One hundred and thirty-six (136) samples gave blue colonies on mFC agar and required confirmation. E. coli-specific rtPCR showed false-positive results in 23.5% (32/136) of cases. In terms of ease of use, Colilert was the simplest method to use while the MI method provided ease of use comparable to all membrane filtration methods. However, the mFC + E. coli rtPCR assay required highly trained employees for confirmation purposes. In terms of affordability, and considering contamination rate of well water samples tested, the Colilert method and the mFC + E. coli rtPCR assay were at least five times more costly than the MI agar method. Overall, compared with the other two methods tested, the MI agar method offers the most advantages to assess drinking water quality.

scholarly journals Drivers of microbiological quality of household drinking water – a case study in rural Ethiopia

2017 ◽  
Vol 16 (2) ◽  
pp. 275-288 ◽  
Author(s):  
Muhammed A. Usman ◽  
Nicolas Gerber ◽  
Evita H. Pangaribowo
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Rural Areas ◽  
Fecal Contamination ◽  
Microbiological Quality ◽  
Water Sources ◽  
Multiple Use ◽  
Water Safety ◽  
E Coli

Abstract This study aims at assessing the determinants of microbiological contamination of household drinking water under multiple-use water systems in rural areas of Ethiopia. For this analysis, a random sample of 454 households was surveyed between February and March 2014, and water samples from community sources and household storage containers were collected and tested for fecal contamination. The number of Escherichia coli (E. coli) colony-forming units per 100 mL water was used as an indicator of fecal contamination. The microbiological tests demonstrated that 58% of household stored water samples and 38% of protected community water sources were contaminated with E. coli. Moreover, most improved water sources often considered to provide safe water showed the presence of E. coli. The result shows that households' stored water collected from unprotected wells/springs had higher levels of E. coli than stored water from alternative sources. Distance to water sources and water collection containers are also strongly associated with stored water quality. To ensure the quality of stored water, the study suggests that there is a need to promote water safety from the point-of-source to point-of-use, with due considerations for the linkages between water and agriculture to advance the Sustainable Development Goal 6 of ensuring access to clean water for everyone.

scholarly journals Microbiological Contamination of Strawberries from U-Pick Farms in Guangzhou, China

2019 ◽  
Vol 16 (24) ◽  
pp. 4910
Author(s):  
Xiaohong Wei ◽  
Shuiping Hou ◽  
Xinhong Pan ◽  
Conghui Xu ◽  
Juntao Li ◽  
...  
Keyword(s):  
Irrigation Water ◽  
Water Samples ◽  
Southern China ◽  
Microbiological Quality ◽  
Metropolitan Region ◽  
Microbiological Contamination ◽  
Total Coliforms ◽  
E Coli ◽  
Quality Of Irrigation Water

This study quantified the association of rodent fruit damage and the microbiological quality of irrigation water on the risk of microbiological contamination of strawberries collected from 18 U-pick farms across five different districts in the Guangzhou metropolitan region of southern China. Fifty-four composite strawberries samples, with or without evidence of rodent or avian foraging damage (i.e., bitten), along with 16 irrigation water samples, were collected during the spring of 2014 and winter of 2015 from our cohort of 18 farms. Composite strawberry samples and irrigation water were analyzed for total coliforms, E. coli, Salmonella, E. coli O157, Giardia, and Cryptosporidium. Total coliforms and E. coli were detected in 100% and ~90% of irrigation water samples, respectively. In contrast, Cryptosporidium was detected in only two water samples, while Salmonella, E. coli O157, and Giardia were not detected in any water samples. Strawberries with signs of being bitten by wildlife had significantly higher concentrations of total coliforms and E. coli, compared to strawberries with no physical evidence of rodent damage (p < 0.001). Similarly, Cryptosporidium was detected in 7/18 (39%) of bitten, 4/18 (22%) of edge, and 5/18 (28%) of central strawberry samples, respectively. Concentration of E. coli on strawberries (p < 0.001), air temperature (p = 0.025), and presence of Cryptosporidium in irrigation water (p < 0.001) were all associated with the risk of Cryptosporidium contamination on strawberries. Salmonella and Giardia were detected in <4% strawberry samples and E. coli O157 was not detected in any samples. These results indicate the potential food safety and public health risks of consuming unwashed strawberries from U-pick farms, and the need for improved rodent biosecurity of U-pick strawberry fields and enhanced microbiological quality of irrigation water used at these facilities.

Microbial Quality of Water Supply to an Urban Community in Trinidad

2002 ◽  
Vol 65 (8) ◽  
pp. 1297-1303 ◽  
Author(s):  
LAVAUGHN AGARD ◽  
CORLIS ALEXANDER ◽  
SIMONE GREEN ◽  
MICHAEL JACKSON ◽  
SANJEEV PATEL ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Residual Chlorine ◽  
Reservoir Water ◽  
Total Coliforms ◽  
E Coli ◽  
Significant Difference ◽  
Thermotolerant Coliforms ◽  
The Difference

A microbiological study was conducted to determine the quality of the water supply to an urban community in San Fernando proper in south Trinidad using total coliforms and thermotolerant coliforms as indicators of water pollution. The membrane filter technique was used to detect total coliforms and thermotolerant coliforms on endo agar and MFc agar, respectively. The residual chlorine levels in water from the reservoir, from standpipes along the distribution line, and from households were determined with a commercial test kit. Of a total of 104 drinking water samples obtained from households, 84 (80.8%), 56 (53.8%), and 70 (67.3%) tested positive for total coliforms, thermotolerant coliforms, and Escherichia coli, respectively. The difference was statistically significant (P &lt; 0.05, χ2). Of the 81 water samples collected from the Water and Sewerage Authority (WASA) main supply to households, 38 (46.9%), 13 (16.0%), and 27 (33.3%) were contaminated by total coliforms, thermotolerant coliforms, and E. coli, respectively, and the difference was statistically significant (P &lt; 0.05, χ2). Eight (20.5%) of 39 water samples from standpipes along the distribution line tested positive for total coliforms, compared with 4 (10.3%) samples testing positive for thermotolerant coliforms. All five samples of treated water obtained from the reservoir tested negative for coliforms. There was a significant difference (P = 0.004) in the mean residual chlorine levels in water from the reservoir, water from standpipes, and water from households. Similarly, as the level of residual chlorine decreased, there was a statistically significant (P = 0.004) increase in the prevalence of total coliforms in water from 0.0% (treated reservoir water) to 15.2% (standpipe) to 53.5% (household mains) to 80.0% (household drinking water). There was also a statistically significant difference (P &lt; 0.001, χ2) in the prevalence of total coliforms in drinking water and in water from the WASA main supply to households. Of the 105 E. coli strains tested, 7 (6.7%), 16 (15.2%), and 22 (21.0%) were mucoid, hemolytic, and non–sorbitol fermenters, respectively. It was concluded that the high degree of contamination of drinking water in households poses a health hazard to consumers.

scholarly journals Bacteriological and physicochemical quality of drinking water in Kobo town, Northern Ethiopia

2021 ◽  
Author(s):  
Baye Sitotaw ◽  
Molla Nigus
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Physicochemical Parameters ◽  
Membrane Filtration ◽  
Microbiological Quality ◽  
National Standards ◽  
Fecal Coliforms ◽  
Northern Ethiopia ◽  
Waterborne Diseases

Abstract Despite drinking water supply in Kobo town is from a borehole through pipes, a high incidence of waterborne diseases are frequently reported. Hence, this study aimed to assess the bacteriological and physicochemical drinking water quality in Kobo town. One hundred and twenty water samples were collected from four sampling sites (the source, reservoir, taps, and households' containers) from February to April 2020. Total and fecal coliforms were counted from the water samples using membrane filtration while selected physicochemical parameters were determined using standard methods. The mean counts of total and fecal coliforms ranged from 3.9 to 22.9 and 1 to 13.6 CFU/100 mL, respectively. Hence, all water samples did not satisfy the WHO guidelines and national standards. There were statistically significant differences in the coliform counts between the different sampling sites, and the counts were significantly higher in the taps and households' containers compared to the counts in the source and reservoir (p &lt; 0.05). All physicochemical parameters, except for temperature, were within the recommended acceptable limits. High coliform count in the water system demands proper maintenance of the distribution line and good hygiene practices at household level to improve the microbiological quality of drinking water in Kobo town.

scholarly journals Pollution Physique Et Bactériologique De L’eau Du Fleuve Dans La Basse Vallée De L’ouémé Pendant Les Périodes De Basses Et Hautes Eaux Au Bénin

2017 ◽  
Vol 13 (33) ◽  
pp. 167
Author(s):  
Adjagodo A. ◽  
Agassounon Djikpo Tchibozo M. ◽  
Kelomè N.C. ◽  
Vissin E.W. ◽  
Agbossou E.
Keyword(s):  
Water Samples ◽  
Membrane Filtration ◽  
High Water ◽  
Total Coliforms ◽  
E Coli ◽  
Sampling Campaign ◽  
High Water Period ◽  
Thermotolerant Coliforms

The objective of this study is to assess the water river quality of the Lower Valley of Ouémé in Benin. Two river water sampling campaigns were carried out during low and high water. At each sampling campaign, eleven (11) sampling sites were selected and at each site four samples were taken, making a total of 44 water samples. Hydrogen potential, dissolved oxygen, suspended matter and turbidity were measured in situ. Fecal contamination germs such as total coliforms, thermotolerant coliforms, Escherichia coli and fecal enterococci were counted by the membrane filtration technique. The results of the physical analyzes reveal that the pH measured in the water samples conformed to the WHO standard except turbidity. The results of the bacteriological analyzes in 100 mL of water sample of the river reveal average bacterial loads in periods of low and high waters which vary respectively from 2.57.10 2 ± 451 CFU and 3.35.102 ± 459 CFU for total coliforms; 1.42.102 ± 315 CFU and 1.55.102 ± 251 for thermotolerant coliforms; 0,79.102 ± 216 CFU and 1.55.102 ± 251 for E. coli. The Enterococci are absent in the waters during these two periods. The high burden of these germs counted in the high water period may be due runoff phenomenon and unhygienic behavior observable in the study area.

Commercialization Conditions and Practices Influence the Microbiological Quality of Mineral Waters

2008 ◽  
Vol 71 (6) ◽  
pp. 1253-1257 ◽  
Author(s):  
SÉRGIO A. P. NUNES FILHO ◽  
ANDERSON S. SANT'ANA ◽  
ADRIANO G. CRUZ
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Water Samples ◽  
Mineral Water ◽  
Microbiological Quality ◽  
Mineral Waters ◽  
Fecal Coliforms ◽  
Street Vendors ◽  
Total Coliforms ◽  
Bottled Mineral Water

The objective of the present study was to determine the microbiological quality of bottled mineral water marketed in commercial establishments and by street vendors and to evaluate the influence of the storage and maintenance conditions on the microbiological quality of the product. Ten samples from the same batches of five different brands of water were analyzed, for a total of 50 samples. Of the five brands analyzed, only one (brand A), when collected in a commercial establishment, complied with the legal Brazilian standards for mineral water with respect to the presence of total coliforms, fecal coliforms, and Pseudomonas aeruginosa. The remaining samples failed to comply with these microbiological standards for at least one of the parameters evaluated. The water samples obtained from street vendors were inferior in microbiological quality to samples from the same batch that were obtained from commercial establishments.

scholarly journals Point-of-Use Water Treatment Methods and the Microbiological Quality of Drinking Water in a Peri-Urban Community of Bonendale, Douala IV, Cameroon

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ngouakam H ◽  
◽  
Fru Cho J ◽  
Tientche B ◽  
◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Microbiological Quality ◽  
Coliform Bacteria ◽  
Cross Sectional ◽  
Potential Health ◽  
Coliform Count ◽  
Point Of Use ◽  
Dug Wells

Background: The study aimed at assessing the knowledge of Bonendale populations related to safe drinking water; determine the microbiological quality and the household treatment practices of drinking water at the point of use (PoU). Methods: The study was descriptive and cross-sectional, conducted between November 2017 and November 2018 in Bonendale, Douala IV. A systematic random sampling method was used to select 237 households. Results: The main source of drinking water in the study population was dug wells (64.9%). The major activity around the boreholes was agriculture 50% (6/12) while agriculture and livestock rearing were practiced around 34.3% (12/35) and 42.8% (15/35) of dug wells respectively. Nearly half 110 (46.4%) of respondents had a good knowledge of physical properties of drinking water. Fifty-nine water samples out of a total of 60 tested (98.3%) were contaminated by coliform bacteria. Analysis of water samples indicated that 47.6% (10/21) of dug wells, 37.0% (10/27) of Camwater, and 41.2% (5/12) of boreholes had a total coliform count varying between 101-1000 CFU/100mL. And only a single Camwater water sample 1 (137%) had a coliform count of 0 CFU/100mL. Conclusion: These findings indicated the poor microbiological quality of point water used by Bonendale populations representing an important potential health risk of water-borne diseases. The results also reveal that a very high proportion of households treat their PoU before drinking.

scholarly journals Microbiological quality of shellfish and evaluation of compact dry EC for detecting total coliforms and Escherichia coli

2020 ◽  
Vol 49 (1) ◽  
pp. 32-39 ◽  
Author(s):  
A. Vásquez García ◽  
S.H. Gomes de Sá ◽  
G. de Sousa Silva ◽  
J.E. Mejia Ballesteros ◽  
E. Barbieri ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Conventional Method ◽  
Microbiological Quality ◽  
Correlation Coefficients ◽  
Mean Values ◽  
Total Coliforms ◽  
E Coli ◽  
The Mean

The objective of this study was to evaluate the microbiological quality of oysters and mussels grown in Cananéia, Brazil, by analysing mesophiles, psychrothophic bacteria, moulds and yeasts, Staphylococcus aureus, and Salmonella spp., and to compare the efficiency of Compact Dry EC method and the conventional method for counting of total coliforms and Escherichia coli. The microbial analysis showed that the mean values of mesophilic counts were 3.14±0.81 log CFU g−1 for oysters and 3.92±0.90 for mussels; the mean values of psychrophilic counts were 2.78±0.75 log CFU g−1 for oysters and 3.22±0.75 log CFU g−1 for mussels; the mean values of mould and yeast counts were 3.70±0.58 log CFU g−1 for oysters and 3.33±0.81 log CFU g−1 for mussels. Salmonella spp. did not present positive results, and the maximal count of Staphylococcus aureus was 1.7 log CFU g−1, therefore, within the limits established in the legislation. The correlation coefficients between the Compact Dry EC method and conventional method were >0.87 for total coliform and E. coli counts for both types of shellfish. The data in this study show that the Compact Dry EC method is an acceptable alternative to conventional methods for enumeration of total coliforms and E. coli in shellfish.

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