scholarly journals Is drinking water from ‘improved sources’ really safe? A case study in the Logone valley (Chad-Cameroon)

2013 ◽  
Vol 11 (4) ◽  
pp. 748-761 ◽  
Author(s):  
S. Sorlini ◽  
D. Palazzini ◽  
A. Mbawala ◽  
M. B. Ngassoum ◽  
M. C. Collivignarelli
Keyword(s):  
Health Risks ◽  
Membrane Filtration ◽  
Microbiological Quality ◽  
Health Concern ◽  
Water Safety ◽  
Domestic Water ◽  
Filtration Method ◽  
E Coli ◽  
Piped Water ◽  
Joint Monitoring

Within a cooperation project coordinated by the Association for Rural Cooperation in Africa and Latin America (ACRA) Foundation, water supplies were sampled across the villages of the Logone valley (Chad-Cameroon) mostly from boreholes, open wells, rivers and lakes as well as from some piped water. Microbiological analyses and sanitary inspections were carried out at each source. The microbiological quality was determined by analysis of indicators of faecal contamination, Escherichia coli, Enterococci and Salmonellae, using the membrane filtration method. Sanitary inspections were done using WHO query forms. The assessment confirmed that there are several parameters of health concern in the studied area; bacteria of faecal origins are the most significant. Furthermore, this study demonstrated that Joint Monitoring Programme (JMP) classification and E. coli measurement are not sufficient to state water safety. In fact, in the studied area, JMP defined ‘improved sources’ may provide unsafe water depending on their structure and sources without E. coli may have Enterococci and Salmonellae. Sanitary inspections also revealed high health risks for some boreholes. In other cases, sources with low sanitary risk and no E. coli were contaminated by Enterococci and Salmonellae. Better management and protection of the sources, hygiene improvement and domestic water treatment before consumption are possible solutions to reduce health risks in the Logone valley.

An Improved Membrane Filtration Method for Enumeration of Faecal Coliforms and E. Coli by a Fluorogenic β-Glucuronidase Assay

1993 ◽  
Vol 27 (3-4) ◽  
pp. 267-270 ◽  
Author(s):  
M. T. Augoustinos ◽  
N. A. Grabow ◽  
B. Genthe ◽  
R. Kfir
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
Membrane Filtration ◽  
Faecal Coliforms ◽  
Environmental Waters ◽  
Filtration Method ◽  
E Coli ◽  
Wide Range ◽  
Pure Cultures ◽  
Glucuronidase Assay

A fluorogenic β-glucuronidase assay comprising membrane filtration followed by selective enumeration on m-FC agar at 44.5°C and further confirmation using tlie 4-metliylumbelliferyl-β-D-glucuronide (MUG) containing medium was evaluated for the detection of Escherichia coli in water. A total of 200 typical blue and non-typical blue colonies were isolated from sea and fresh water samples using initial selective enumeration on m-FC agar. Pure cultures of the selected colonies were further tested using the MUG assay and identified using the API 20E method. Of the colonies tested which were shown to be positive using the MUG assay 99.4% were Escherichia coli. The results of this study indicate the combination of the m-FC method followed by the MUG assay to be highly efficient for the selection and confirmation of E. coli from a wide range of environmental waters.

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 Methods for enumeratingEscherichia coliin subtropical waters

1991 ◽  
Vol 106 (2) ◽  
pp. 345-354 ◽  
Author(s):  
W. H. S. Cheung ◽  
D. K. K. Ha ◽  
K. Y. Yeung ◽  
R. P. S. Hung
Keyword(s):  
Membrane Filtration ◽  
Good Alternative ◽  
Environmental Waters ◽  
Filtration Method ◽  
E Coli ◽  
Bacterial Indicator ◽  
Urease Test ◽  
The Uk ◽  
Mls Method

SUMMARYThe standard membrane filtration method of the UK has been modified in order to improve its specificity for enumeratingEscherichia coliin the subtropical waters of Hong Kong. This involves incorporating into the membrane lauryl sulphate (mLS) method either anin situurease test (the mLS-UA method), or anin situβ-glucuronidase test (the mLS-GUD method). The false-positive errors of the mLS-UA and mLS-GUD methods are low, ranging from 3–5%. A comparison between the membrane filtration (mLS-UA) method and the multiple tube technique in testingE. coliin subtropical beach-waters has demonstrated that the former can give much more precise counts, and is the method of choice for such a purpose. The mLS-GUD method, for which automated counting ofE. colicolonies is possible, is a good alternative to mLS-UA in routine enumeration of this bacterial indicator in environmental waters.

scholarly journals Bacterial Contamination of Drinking Water in Guadalajara, Mexico

2018 ◽  
Author(s):  
Francesca Rubino ◽  
Yahaira Corona ◽  
José Guadalupe Jiménez Pérez ◽  
Charlotte D. Smith
Keyword(s):  
Drinking Water ◽  
Microbiological Quality ◽  
Total Coliform ◽  
Coliform Bacteria ◽  
E Coli ◽  
Chlorine Residual ◽  
Piped Water ◽  
Regulatory Limits ◽  
Access To Water

In many regions where drinking water supply is intermittent and unreliable, households adapt by storing water in cisterns or rooftop tanks. Both intermittent supply and stored water can be vulnerable to contamination by microorganisms with deleterious health effects. The Guadalajara Metropolitan Area is a rapidly growing urban center with over five million residents where household storage is nearly ubiquitous. This pilot study was conducted in July 2018 to examine the microbiological quality of drinking water in Guadalajara. Samples were tested for free available chlorine residual, total coliform bacteria, and E. coli. A survey on access to water and public perspectives was also conducted. Water exiting rooftop tanks exceeded regulatory limits for total coliform levels in half of the homes studied. Piped water arriving at two homes had total coliform levels that far exceeded regulatory limits. No E. coli were detected in any of the samples. Only 35% of homes had a chlorine residual between the recommended 0.2 and 1.5 mg/L. Many homes reported unpleasant odors and colors. Only 7% of residents drank the piped water. Future studies are needed, especially during April and May when many homes reported a higher disruption to water service.

scholarly journals Sanitary Status and Occurrence of Some Water-Borne Pathogens in Well and Surface Waters of Panhauya Community and Ahmadu Bello University Farm, Zaria

2020 ◽  
Vol 5 (2) ◽  
pp. 138-147
Author(s):  
S. L. Afegbua ◽  
Keyword(s):  
Drinking Water ◽  
Surface Waters ◽  
Water Samples ◽  
Universal Access ◽  
Microbiological Quality ◽  
Health Concern ◽  
Salmonella Spp ◽  
Open Defecation ◽  
E Coli ◽  
Water Borne

The Sustainable Development Goal on sanitation aims to achieve universal access to good health, affordable drinking water, sanitation and an end to open defeacation by 2030. The recent ranking of Nigeria as first globally for open defecation is of public and environmental health concern. This study assessed the sanitary condition and the microbiological quality of well and surface waters of Panhauya community and Ahmadu Bello University farm, Zaria, and the antibiogram of the bacterial isolates.. Based on the WHO criteria, the sanitary inspection showed that 16.7%, 54.2%, 25% and 4.2% of the water sampling points had a very high, high, intermediate and low risk of contamination respectively. Occurrence of Escherichia coli, Giardia lamblia, Entamoeba histolytica, Pseudomonas aeruginosa, Salmonella spp and Vibrio cholerae in water samples from Panhuaya community was 87.5%, 75%, 68.8%, 50%, 25% and 12.5% respectively. In ABU farm Shika, the occurrence was; E. coli (75%), E. histolytica (63%), G. lamblia and Salmonella spp. All E. coli isolates exhibited high multidrug resistance to antibiotics screened with a MAR index of 0.3-0.8. The drinking water sources in Panhuaya and ABU farm were unsafe and the presence of these pathogens in the water samples may be attributed to a number of factors including poor sanitation, manure application and open defecation practice. This indicates a public health risk to the residents and emphasises the need for safe water supplies sanitation and antibiotic stewardship. Keywords: Well water; surface water; sanitary inspection; open defecation; water-borne pathogens; Zaria.

scholarly journals Bacterial Contamination of Drinking Water in Guadalajara, Mexico

2018 ◽  
Vol 16 (1) ◽  
pp. 67 ◽  
Author(s):  
Francesca Rubino ◽  
Yahaira Corona ◽  
José Guadalupe Jiménez Pérez ◽  
Charlotte Smith
Keyword(s):  
Drinking Water ◽  
Microbiological Quality ◽  
Total Coliform ◽  
Coliform Bacteria ◽  
E Coli ◽  
Chlorine Residual ◽  
Piped Water ◽  
Regulatory Limits ◽  
Access To Water

In many regions where drinking water supply is intermittent and unreliable, households adapt by storing water in cisterns or rooftop tanks. Both intermittent supply and stored water can be vulnerable to contamination by microorganisms with deleterious health effects. The Metropolitan Zone of Guadalajara is a rapidly growing urban center with over five million residents where household storage is nearly ubiquitous. This pilot study was conducted in July 2018 to examine the microbiological quality of drinking water in Guadalajara. Samples were tested for free available chlorine residual, total coliform bacteria, and Escherichia coli. A survey on access to water and public perspectives was also conducted. Water exiting rooftop tanks exceeded regulatory limits for total coliform levels in half of the homes studied. Piped water arriving at two homes had total coliform levels that far exceeded regulatory limits. No E. coli were detected in any of the samples. Only 35% of homes had a chlorine residual between the recommended 0.2 and 1.5 mg/L. Many homes reported unpleasant odors and colors. Only 7% of residents drank the piped water. Future studies are needed, especially during April and May when many homes reported a higher disruption to water service.

scholarly journals The microbiological quality of potable water on board ships docking in the UK and the Channel Islands: an association of Port Health Authorities and Health Protection Agency Study

2008 ◽  
Vol 6 (2) ◽  
pp. 215-224 ◽  
Author(s):  
P. Grenfell ◽  
C. L. Little ◽  
S. Surman-Lee ◽  
M. Greenwood ◽  
J. Averns ◽  
...  
Keyword(s):  
Water Quality ◽  
Potable Water ◽  
Microbiological Quality ◽  
Water Safety ◽  
E Coli ◽  
Chlorine Residual ◽  
Health Authorities ◽  
Processing Water ◽  
The Uk ◽  
Port Health

Providing safe potable water onboard vessels presents particular challenges and contamination can occur directly from source waters as well as during loading, storage and distribution. Between May and October 2005, 950 potable water samples were collected from 342 ships docking at ports. Comparison with Guidelines found 9% of samples contained coliforms, Escherichia coli or enterococci and 2.8% had faecal indicators (E. coli or enterococci). Action levels of aerobic colony count (ACC) bacteria were detected in 20% (22°C) and 21.5% (37°C) of samples. ACC results from one-off sampling are not informative as this does not enable port health authorities to monitor ACC trends. They should be removed as a routine criterion for remedial action and vessels should adopt the WHO Water Safety Plan approach, whilst continuing to monitor water quality with public health-based indicators (e.g. chlorine residual, coliforms, E. coli and enterococci). Logistic regression analyses identified practices associated with water quality. Practices protective against coliforms, E. coli or enterococci in potable supplies were: good hose hygiene, processing water onboard, maintaining free chlorine residual at ≥0.2 mg/L. This emphasizes the importance of good hygiene during potable water loading and maintaining adequate disinfection of supplies onboard.

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 Management of Microbiological Contamination of the Water Network of a Newly Built Hospital Pavilion

Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 75
Author(s):  
Osvalda De Giglio ◽  
Giusy Diella ◽  
Marco Lopuzzo ◽  
Francesco Triggiano ◽  
Carla Calia ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Microbiological Quality ◽  
Silver Ions ◽  
Waterborne Diseases ◽  
Water Safety ◽  
Water Network ◽  
E Coli ◽  
Quality Of Water ◽  
Water Safety Plan

The good installation, as well as commissioning plan, of a water network is a crucial step in reducing the risk of waterborne diseases. The aim of this study was to monitor the microbiological quality of water from a newly built pavilion before it commenced operation. Overall, 91 water samples were tested for coliforms, Escherichia coli, enterococci, Pseudomonas aeruginosa and Legionella at three different times: T0 (without any water treatment), T1 (after treatment with hydrogen peroxide and silver ions at initial concentration of 20 mg/L and after flushing of water for 20 min/day for seven successive days) and T2 (15 days later). Coliforms were detected in 47.3% of samples at T0, 36.3% at T1 and 4.4% at T2. E. coli was isolated in 4.4% of the samples only at T1, while enterococci appeared in 12.1% of the samples at T1 and in 2.2% at T2. P. aeruginosa was isolated in 50.5% of the samples at T0, 29.7% at T1 and 1.1% at T2. Legionella pneumophila serogroup 8 was isolated in 80.2% of the samples at T0, 36.3% at T1 and 2.2% at T2. Our results confirmed the need for a water safety plan in new hospital pavilions to prevent the risk of waterborne diseases.

Antimicrobial Resistance and Genetic Profiling of Escherichia coli from a Commercial Beef Packing Plant†

2006 ◽  
Vol 69 (7) ◽  
pp. 1508-1513 ◽  
Author(s):  
MUEEN ASLAM ◽  
CARA SERVICE
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Membrane Filtration ◽  
Antimicrobial Agents ◽  
Random Amplified Polymorphic Dna ◽  
Ground Beef ◽  
Resistant Bacteria ◽  
Filtration Method ◽  
E Coli ◽  
Beef Processing

The objective of this study was to investigate the extent of antimicrobial resistance and to genetically characterize resistant Escherichia coli recovered from a commercial beef packing plant. E. coli isolates were recovered by a hydrophobic grid membrane filtration method by direct plating on SD-39 medium. A total of 284 isolates comprising 71, 36, 55, 52, and 70 isolates from animal hides, washed carcasses, conveyers, beef trimmings, and ground beef, respectively, were analyzed. The susceptibility of E. coli isolates to 15 antimicrobial agents was evaluated with an automated broth microdilution system, and the genetic characterization of these isolates was performed by the random amplified polymorphic DNA (RAPD) method. Of the 284 E. coli isolates, 56% were sensitive to all 15 antimicrobial agents. Resistance to tetracycline, ampicillin, and streptomycin was observed in 38, 9, and 6% of the isolates, respectively. Resistance to one or more antimicrobial agents was observed in 51% of the E. coli isolates recovered from the hides but in only 25% of the E. coli from the washed carcasses. Resistance to one or more antimicrobial agents was observed in 49, 50, and 37% of the isolates recovered from conveyers, beef trimmings, and ground beef, respectively. The RAPD pattern data showed that the majority of resistant E. coli isolates were genetically diverse. Only a few RAPD types of resistant strains were shared among various sample sources. The results of this study suggest that antimicrobial-resistant E. coli isolates were prevalent during all stages of commercial beef processing and that considerably higher numbers of resistant E. coli were present on conveyers, beef trimmings, and ground beef than on dressed carcasses. This stresses the need for improving hygienic conditions during all stages of commercial beef processing and meatpacking to avoid the risks of transfer of antimicrobial-resistant bacteria to humans.

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