scholarly journals Comparison of four β-glucuronidase and β-galactosidase-based commercial culture methods used to detect Escherichia coli and total coliforms in water

2014 ◽  
Vol 13 (2) ◽  
pp. 340-352 ◽  
Author(s):  
Andrée F. Maheux ◽  
Vanessa Dion-Dupont ◽  
Sébastien Bouchard ◽  
Marc-Antoine Bisson ◽  
Michel G. Bergeron ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Water Samples ◽  
Microbiological Quality ◽  
Total Coliform ◽  
Ease Of Use ◽  
Well Water ◽  
Positive Signal ◽  
Culture Methods ◽  
E Coli

The MI agar, Colilert®, Chromocult coliform® agar, and DC with BCIG agar chromogenic culture-based methods used to assess microbiological quality of drinking water were compared in terms of their ubiquity, sensitivity, ease of use, growth of atypical colonies and affordability. For ubiquity, 129 total coliform (representing 76 species) and 19 Escherichia coli strains were tested. Then, 635 1-L well water samples were divided into 100 mL subsamples for testing by all four methods. Test results showed that 70.5, 52.7, 36.4, and 23.3% of the non-E. coli total coliform strains and 94.7, 94.7, 89.5, and 89.5% of the 19 E. coli strains yielded a positive signal with the four methods, respectively. They also yielded a total coliform positive signal for 66.5, 51.7, 64.9, and 55.0% and an E. coli positive signal for 16.1, 14.8, 17.3, and 13.4% of the 635 well water samples tested, respectively. Results showed that Colilert® is the most expensive method tested in terms of reactants, yet it is the easiest to use. Large numbers of atypical colonies were also often observed on Chromocult coliform® and DC with BCIG, thereby challenging the target microorganism count. Thus, the MI agar method seems to be the best option for the assessment of drinking water quality.

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 A comparison between minerals-modified glutamate medium and lauryl tryptose lactose broth for the enumeration of Escherichia coli and coliform organisms in water by the multiple tube method

1980 ◽  
Vol 85 (1) ◽  
pp. 35-49 ◽  
Author(s):  
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Water Samples ◽  
Total Coliform ◽  
Faecal Contamination ◽  
E Coli ◽  
Chlorinated Drinking Water ◽  
Laboratory Trial ◽  
Gas Reactions ◽  
Better Than

SummaryIn a multi-laboratory trial, minerals-modified glutamate medium (MMGM) was compared with lauryl tryptose lactose broth (LTLB) in the multiple tube method for the enumeration of coliform organisms, including Escherichia coli, in water. Samples of raw and chlorinated waters yielded a total of 2313 positive tube-reactions with MMGM and 2174 with LTLB. These were interpreted either as E. coli; other coliform organisms; or as false positive reactions. The results at first reading (18 or 24 h) and at 48 h have been analysed statistically in terms of (i) most probable numbers of coliform organisms; (ii) positive reactions and their interpretation; and (iii) whether or not the sample yielded any E. coli or other coliform organisms. All three analyses indicated the same trends. For the detection of E. coli in raw waters LTLB was better than MMGM at 18–24 h, but MMGM was better at 48 h with waters containing small numbers of coliform organisms; for raw waters with greater numbers of organisms, both media performed equally well. Analysis of a subset of samples read at both 18 and 24 h indicated that the superiority of LTLB over MMGM with raw waters disappeared by 24 h. For chlorinated waters, LTLB yielded more positive gas reactions at 18–24 h, but fewer of these were E. coli than with MMGM; at 48 h MMGM was clearly better than LTLB for total coliform organisms including E. coli – especially if the numbers were small. MMGM therefore remains the medium of choice for the detection of E. coli as an indicator of faecal contamination of chlorinated drinking water supplies. It is also better for the detection of small numbers of E. coli in other waters.

scholarly journals Borehole water: a potential health risk to rural communities in South Africa

2018 ◽  
Vol 19 (1) ◽  
pp. 128-136 ◽  
Author(s):  
S. Taonameso ◽  
L. S. Mudau ◽  
A. N. Traoré ◽  
N. Potgieter
Keyword(s):  
Drinking Water ◽  
Rural Communities ◽  
Water Samples ◽  
Rural Areas ◽  
Total Coliform ◽  
Water Sources ◽  
Potential Health ◽  
Point Mapping ◽  
E Coli ◽  
Mapping Tool

Abstract Sporadic outbreaks of diarrhoea in children in the Vhembe rural areas could be an indication of contamination in drinking water sources. In areas where improved water sources are used, not all rural households experience the benefits of these improved water sources. Water samples were collected from boreholes in three wards in the Vhembe District to determine microbiological risks over a 5-month period. A Water Point Mapping tool was used to indicate the borehole distribution. Water samples were taken from each functional borehole and analysed for total coliform and Escherichia coli counts, electrical conductivity, pH and temperature. A multiplex PCR protocol was used for identification of pathogenic E. coli. A total of 125 boreholes were identified of which only 12 were functional. Seven boreholes tested positive for total coliforms and E. coli counts. Four boreholes (33.3%) tested positive for diarrhoeagenic E. coli. Fifty-eight percent (58%) of water samples were without health risks, 17% were low risk and 25% could cause infection according to the South African water quality standards. This study indicated the importance of the role of the Municipalities and the maintenance plans that need to ensure that all boreholes are functional and provide safe drinking water to the rural communities.

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 PCR detection of Vibrio cholerae, Escherichia coli, and Salmonella sp. from bottled drinking water in Iran

2018 ◽  
Vol 12 (09) ◽  
pp. 700-705
Author(s):  
Mojtaba Bonyadian ◽  
Hamdallah Moshtaghi ◽  
Hanie Nadi
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Vibrio Cholerae ◽  
Screening Method ◽  
Chain Reaction ◽  
Culture Methods ◽  
E Coli ◽  
Drinking Waters ◽  
Polymerase Chain

Introduction: The quality of drinking water has an important role in human health. This study was aimed to detect Escherichia. coli, Salmonella sp. and Vibrio cholerae from bottled drinking waters produced in Iran. Methodology: A total of 240 samples of bottled water of different brands were collected for testing between March 2015 to December 2015 in Shahrekord-Iran. Samples were examined by polymerase chain reaction (PCR) combined with culture methods for the detection of E. coli, Salmonella sp., and V. cholerae. Results: The results of PCR revealed that the uidA gene from E. coli, IpaB gene from Salmonella sp, and epsM gene from V. cholerae were detected in 6 (2.5%), 1 (0.4 %), 0 (0%) of the samples, respectively. But in culture methods, only E. coli 5 (2.1%) were isolated from the samples. The contamination with E. coli was significantly higher (P < 0.05) in water produced during the hot seasons than the cold seasons. Conclusions: This study confirmed the presence of Escherichia coli as the main microorganism in bottle drinking water in Iran. Also, our study showed that PCR can be used as a screening method for monitoring the enteric pathogens in drinking water.

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 Diversity, virulence and antibiogram traits of Escherichia coli recovered from potable water sources in Gharbia, Egypt

2020 ◽  
Vol 18 (3) ◽  
pp. 430-438
Author(s):  
Walid Elmonir ◽  
Etab Mohamed Abo Remela ◽  
Yasmine Alwakil
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Water Samples ◽  
Potable Water ◽  
Multiple Drug Resistance ◽  
Tap Water ◽  
Water Sources ◽  
Multiple Drug ◽  
Well Water ◽  
E Coli

Abstract This study aimed to assess the public health risk of coliforms and Escherichia coli contamination of potable water sources in Egypt. A total of 150 water samples (100 tap and 50 well) were collected from five districts in Gharbia governorate, Egypt. High rates of coliforms contamination were recorded in 52 and 76% of examined tap and well water samples, respectively. E. coli strains were detected in 16% of the water samples (15% tap water and 18% well water; 23.7% rural and 8.1% urban). Rural water sources were 3.5 times more likely to be contaminated than urban sources (P = 0.01). Eight (33.3%) E. coli isolates were Shiga toxin-producing E. coli (STEC). Multiple drug resistance (MDR) was observed for 62.5% of the isolates. Seven (29.2%) E. coli isolates harboured at least one of the extended-spectrum beta-lactamase (ESBL) genes. The majority (87.5%) of the STEC isolates were MDRs and harboured ESBL genes. STEC isolates were significantly more likely to resist six classes of antibiotics than non-STEC isolates. This is the first report of potable water contamination with MDR-STEC in Egypt. This study highlights an alarming public health threat that necessitates preventive interventions for public and environmental safety.

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.

Effect of Heat Shock on Recovery of Escherichia coli from Drinking Water

1991 ◽  
Vol 24 (2) ◽  
pp. 85-88 ◽  
Author(s):  
C. Berry ◽  
B. J. Lloyd ◽  
J. S. Colbourne
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Heat Shock ◽  
Legionella Pneumophila ◽  
Traditional Culture ◽  
Culturable Bacteria ◽  
Water Industry ◽  
Culture Methods ◽  
E Coli ◽  
Response To Stress

Recent studies on the survival of bacteria in the aquatic environment have suggested that bacteria in water may enter a ‘viable non-culturable' phase in response to stress. Such bacteria are a cause of concern if pathogenic, because they cannot be detected using traditional culture methods. It has been found that mild heat shock causes viable non-culturable Legionella pneumophila to grow on laboratory media. The survival and culturability of Escherichia coli in sterile drinking water was investigated. The isolates used were from the environment rather than clinical. As expected, the count by culture on nutrient agar declined with time while the microscopy count remained approximately constant. Under laboratory conditions the E. coli isolates survived up to three months or more. After three months a portion of each suspension was heat shocked at 35°C for 20 minutes and then assayed by culture and microscopy immediately. An average increase of three log cycles was noted in the count by culture. There was no corresponding increase in the count by microscopy. Thus E. coli appears to exhibit viable non-culturable behaviour. Heat shock causes non-culturable bacteria to regain their ability to grow on artificial media. Such a finding may have several implications for the water industry and microbiology in general.

CONSUMPTION OF RAW WATER – THE HEALTH RISKS RELATED TO THE PRESENCE OF HEAVY METALS AND „ESCHERICHIA COLI“

2021 ◽  
Author(s):  
Mirjana Grujović ◽  
◽  
Katarina Mladenović ◽  
Zoran Simić ◽  
Simona Đuretanović
Keyword(s):  
Escherichia Coli ◽  
Trace Elements ◽  
Health Risks ◽  
Water Samples ◽  
Major And Trace Elements ◽  
Total Coliform ◽  
Coliform Bacteria ◽  
Mountain Stream ◽  
E Coli ◽  
Colorimetric Test

This research aimed to investigate the quality of drinking water from the rural area of village Pajsijević (Šumadija, central Serbia). The water is consumed as raw since it is not purified or chlorinated before consumption. The water was collected at three sampling points – in the spring of Kotlenik Mountain stream (W1 sample), in the local reservoir (W2 sample), and from the tap (W3 sample). Also, the sediment samples (soil and sand) were analyzed, too. The health risks related to the presence and concentration of some major and trace elements (Ca, Cr, Cu, Fe, Mg, Mn, Ni, Zn) and N, NO, NN3, NH4, P, P2O5, and PO4 were evaluated. Additionally, the presence and the number of total coliform bacteria and Escherichia coli (as an indicator of fecal contamination) were evaluated. The concentrations of analyzed major and trace elements in all water samples were below those at which toxic effects may occur. The exception was the concentrations of Fe (2.02 – 2012 mg/L), which were higher than is allowed. The origin of Fe in water is from sediment (soil and sand), which also showed high content of Fe (3006.0 mg/g and 2229.9 mg/g, respectively). The results of the Colorimetric test indicated the presence of coliform bacteria as well as the presence of E. coli in all water samples. Further research needs to include characterization of isolated coliform bacteria and serological investigation of E. coli strains in order to evaluate the risks of consumption related to waterborne illness.

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